Ajani, PA, Larsson, ME, Woodcock, S, Rubio, A, Farrell, H, Brett, S & Murray, SA 2020, 'Fifteen years of Pseudo-nitzschia in an Australian estuary, including the first potentially toxic P. delicatissima bloom in the southern hemisphere', Estuarine, Coastal and Shelf Science, vol. 236.
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Ajani, PA, Lim, HC, Verma, A, Lassudrie, M, McBean, K, Doblin, MA & Murray, SA 2020, 'First report of the potentially toxic marine diatom Pseudo-nitzschia simulans (Bacillariophyceae) from the East Australian Current', Phycological Research, vol. 68, no. 3, pp. 254-259.
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© 2020 Japanese Society of Phycology Certain species of the marine diatom genus Pseudo-nitzschia are responsible for the production of the domoic acid (DA), a neurotoxin that can bioaccumulate in the food chain and cause amnesic shellfish poisoning (ASP) in animals and humans. This study extends our knowledge by reporting on the first observation of the potentially toxic species Pseudo-nitzschia simulans from this region. One clonal strain of P. simulans was isolated from the East Australian Current and characterized using light and transmission electron microscopy, and phylogenetic analyses based on regions of the internal transcribed spacer (ITS) and the D1–D3 region of the large subunit (LSU) of the nuclear-encoded ribosomal deoxyribonucleic acid (rDNA), as well as examined for DA production as measured by liquid chromatography–mass spectrometry. Although this strain was non-toxic under the defined growth conditions, the results unambiguously confirmed that this isolate is the potentially toxic species P. simulans – the first report of this species from the Southern Hemisphere.
Alderdice, R, Suggett, DJ, Cardenas, A, Hughes, DJ, Kuhl, M, Pernice, M & Voolstra, CR 2020, 'Divergent expression of hypoxia response systems under deoxygenation in reef-forming corals aligns with bleaching susceptibility', GLOBAL CHANGE BIOLOGY, vol. 27, no. 2, pp. 312-326.
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Antonaru, LA, Cardona, T, Larkum, AWD & Nürnberg, DJ 2020, 'Global distribution of a chlorophyll f cyanobacterial marker', ISME Journal, vol. 14, no. 9, pp. 2275-2287.
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© 2020, The Author(s). Some cyanobacteria use light outside the visible spectrum for oxygenic photosynthesis. The far-red light (FRL) region is made accessible through a complex acclimation process that involves the formation of new phycobilisomes and photosystems containing chlorophyll f. Diverse cyanobacteria ranging from unicellular to branched-filamentous forms show this response. These organisms have been isolated from shaded environments such as microbial mats, soil, rock, and stromatolites. However, the full spread of chlorophyll f-containing species in nature is still unknown. Currently, discovering new chlorophyll f cyanobacteria involves lengthy incubation times under selective far-red light. We have used a marker gene to detect chlorophyll f organisms in environmental samples and metagenomic data. This marker, apcE2, encodes a phycobilisome linker associated with FRL-photosynthesis. By focusing on a far-red motif within the sequence, degenerate PCR and BLAST searches can effectively discriminate against the normal chlorophyll a-associated apcE. Even short recovered sequences carry enough information for phylogenetic placement. Markers of chlorophyll f photosynthesis were found in metagenomic datasets from diverse environments around the globe, including cyanobacterial symbionts, hypersaline lakes, corals, and the Arctic/Antarctic regions. This additional information enabled higher phylogenetic resolution supporting the hypothesis that vertical descent, as opposed to horizontal gene transfer, is largely responsible for this phenotype’s distribution.
Babayan, A, Neumann, MHD, Herdean, A, Shaffer, JM, Janning, M, Kobus, F, Loges, S, Di Pasquale, F, Kubista, M, Schlumpberger, M, Lampignano, R, Krahn, T, Schlange, T, Sprenger-Haussels, M, Pantel, K & Kloten, V 2020, 'Multicenter Evaluation of Independent High-Throughput and RT-qPCR Technologies for the Development of Analytical Workflows for Circulating miRNA Analysis', CANCERS, vol. 12, no. 5.
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Badis, Y, Klochkova, TA, Brakel, J, Arce, P, Ostrowski, M, Tringe, SG, Kim, GH & Gachon, CMM 2020, 'Hidden diversity in the oomycete genus Olpidiopsis is a potential hazard to red algal cultivation and conservation worldwide', European Journal of Phycology.
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© 2019, © 2019 British Phycological Society. Marine species of the oomycete genus Olpidiopsis that infect cultivated red macroalgae, most notably Pyropia spp., are one of the main causes of economic loss in the Asian seaweed industry. We recently described novel Olpidiopsis species infecting red algae in Scotland, and thus hypothesized that this genus is more abundant and widespread than previously recognized. Here, we show that the eukaryotic microbiome of macroscopically healthy Porphyra umbilicalis thalli frequently contains marker genes closely related to Olpidiopsis. Thanks to a custom pipeline that allows for de novo OTU and biogeography discovery, and the recovery of precomputed OTUs from large-scale metabarcoding campaigns, we unveil more than 20 unknown Olpidiopsis taxa with a worldwide distribution. Additionally, laboratory-controlled cross-infection experiments show that a Scottish variety of O. porphyrae is virulent on the most commonly cultivated Pyropia yezoensis cultivar in Korea and that conversely, a Korean strain of O. porphyrae successfully infects wild Bangia sp. strains isolated from Scotland. These results provide proof-of-concept that a native Olpidiopsis pathogen may threaten an introduced crop or that an Olpidiopsis pathogen potentially introduced alongside a non-native crop might cross-infect a native European alga. Thus, we draw parallels with several current biosecurity crises, where major risks to native floras and faunas, as well as crops, are caused by the inadvertent introduction of poorly known pathogens through the agricultural and horticultural trades. Therefore, we express concern that the rapid growth of algal cultivation worldwide, linked to international movement of seaweed seed and the absence of biosecurity monitoring or regulation pertaining to this trade, potentially lays the ground for grave ecological and economic crises in the marine environment.
Baird, ME, Wild-Allen, KA, Parslow, J, Mongin, M, Robson, B, Skerratt, J, Rizwi, F, Soja-Wozniak, M, Jones, E, Herzfeld, M, Margvelashvili, N, Andrewartha, J, Langlais, C, Adams, MP, Cherukuru, N, Gustafsson, M, Hadley, S, Ralph, PJ, Rosebrock, U, Schroeder, T, Laiolo, L, Harrison, D & Steven, ADL 2020, 'CSIRO Environmental Modelling Suite (EMS): scientific description of the optical and biogeochemical models (vB3p0)', GEOSCIENTIFIC MODEL DEVELOPMENT, vol. 13, no. 9, pp. 4503-4553.
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Barolo, L, Abbriano, RM, Commault, AS, George, J, Kahlke, T, Fabris, M, Padula, MP, Lopez, A, Ralph, PJ & Pernice, M 2020, 'Perspectives for Glyco-Engineering of Recombinant Biopharmaceuticals from Microalgae', CELLS, vol. 9, no. 3.
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Bates, H, Zavafer, A, Szabó, M & Ralph, PJ 2020, 'The Phenobottle, an open-source photobioreactor platform for environmental simulation', Algal Research, vol. 52.
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© 2020 Elsevier B.V. Microalgal biotechnologies have great potential for biofuels, bioremediation, food technologies and more recently the production of pharmaceuticals. However, a major obstacle to use microalgae industrially is the optimisation of environmental parameters to the microalgal species of interest (light, CO2 availability, nutrients, etc.). If one aims to optimise productivity, the use of photobioreactors (PBRs) is essential. However, the restrictive design of the few commercial bioreactors and their elevated costs (> $10,000 USD ea.) prevents their use as a mainstream tool. To propel microalgal research we present the Phenobottle, a fully customizable open-source PBR platform (consisting of hardware and software). As the optimisation of photosynthesis is a central process to increasing the productivity of microalgae, the Phenobottle is equipped with a chlorophyll a fluorometer and growth sensors to probe metabolic performance in near-real time. An introductory guide is provided and the Phenobottle's sensors are benchmarked against commercial instruments using the model green alga Chlorella vulgaris.
Bodachivskyi, I, Kuzhiumparambil, U & Williams, DBG 2020, 'Catalytic Valorization of Native Biomass in a Deep Eutectic Solvent: A Systematic Approach toward High-Yielding Reactions of Polysaccharides', ACS SUSTAINABLE CHEMISTRY & ENGINEERING, vol. 8, no. 1, pp. 678-685.
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Bodachivskyi, I, Kuzhiumparambil, U & Williams, DBG 2020, 'Towards furfural from the reaction of cellulosic biomass in zinc chloride hydrate solvents', INDUSTRIAL CROPS AND PRODUCTS, vol. 146.
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Bodachivskyi, I, Kuzhiumparambil, U & Williams, DBG 2020, 'Understanding the role of the substrate and the metal triflate acidic catalyst in sugar platform biorefineries: A comprehensive systematic approach to catalytic transformations of (poly)carbohydrates in ethanol', Chemical Engineering Journal, vol. 399.
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© 2020 Elsevier B.V. We systematically explore a range of model conversions of mono- and disaccharides, and of linear and branched polysaccharides under the catalytic action of metal trifluoromethanesulfonates (metal triflates) in ethanol. This highlights the preferred reactivity of specific (poly)carbohydrates, and the interplay between selectivities of the reactions and the dominating catalyst activity (Brønsted or Lewis). It unambiguously delineates that selectivities of acid-catalysed transformations of (poly)carbohydrates into value added platform chemicals rely on the origin of the substrate, any (pre)treatment, the acidic catalyst, and the reaction conditions. The optimised catalytic systems enable very efficient conversion of cellulosic carbohydrates into significantly value added ethyl glucosides (yields up to 63%), ethyl xylosides (yields up to 69%), ethyl levulinate (yields up to 75%), ethyl lactate (yields up to 98%), ethoxyacetaldehyde diethylacetal (yields up to 33%), and furfural diethylacetal (yields up to 44%), depending on the substrate and reaction conditions.
Bodachivskyi, I, Page, CJ, Kuzhiumparambil, U, Hinkley, SFR, Sims, IM & Williams, DBG 2020, 'Dissolution of Cellulose: Are Ionic Liquids Innocent or Noninnocent Solvents?', ACS SUSTAINABLE CHEMISTRY & ENGINEERING, vol. 8, no. 27, pp. 10142-10150.
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Boström-Einarsson, L, Babcock, RC, Bayraktarov, E, Ceccarelli, D, Cook, N, Ferse, SCA, Hancock, B, Harrison, P, Hein, M, Shaver, E, Smith, A, Suggett, D, Stewart-Sinclair, PJ, Vardi, T & McLeod, IM 2020, 'Coral restoration – A systematic review of current methods, successes, failures and future directions', PLoS ONE, vol. 15, no. 1.
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This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication. Coral reef ecosystems have suffered an unprecedented loss of habitat-forming hard corals in recent decades. While marine conservation has historically focused on passive habitat protection, demand for and interest in active restoration has been growing in recent decades. However, a disconnect between coral restoration practitioners, coral reef managers and scientists has resulted in a disjointed field where it is difficult to gain an overview of existing knowledge. To address this, we aimed to synthesise the available knowledge in a comprehensive global review of coral restoration methods, incorporating data from the peer-reviewed scientific literature, complemented with grey literature and through a survey of coral restoration practitioners. We found that coral restoration case studies are dominated by short-term projects, with 60% of all projects reporting less than 18 months of monitoring of the restored sites. Similarly, most projects are relatively small in spatial scale, with a median size of restored area of 100 m2. A diverse range of species are represented in the dataset, with 229 different species from 72 coral genera. Overall, coral restoration projects focused primarily on fast-growing branching corals (59% of studies), and report survival between 60 and 70%. To date, the relatively young field of coral restoration has been plagued by similar ‘growing pains’ as ecological restoration in other ecosystems. These include 1) a lack of clear and achievable objectives, 2) a lack of appropriate and standardised monitoring and reporting and, 3) poorly designed projects in relation to stated objectives. Mitigating these will be crucial to successfully scale up projects, and to retain public trust...
Burt, JA, Camp, EF, Enochs, IC, Johansen, JL, Morgan, KM, Riegl, B & Hoey, AS 2020, 'Insights from extreme coral reefs in a changing world', Coral Reefs, vol. 39, no. 3, pp. 495-507.
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© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Coral reefs are one of the most biodiverse and economically important ecosystems in the world, but they are rapidly degrading due to the effects of global climate change and local anthropogenic stressors. Reef scientists are increasingly studying coral reefs that occur in marginal and extreme environments to understand how organisms respond to, and cope with, environmental stress, and to gain insight into how reef organisms may acclimate or adapt to future environmental change. To date, there have been more than 860 publications describing the biology and/or abiotic conditions of marginal and extreme reef environments, most of which were published within the past decade. These include systems characterized by unusually high, low, and/or variable temperatures (intertidal, lagoonal, high-latitude areas, and shallow seas), turbid or urban environments, acidified habitats, and mesophotic depth, and focus on reefs geographically spread throughout most of the tropics. The papers in this special issue of Coral Reefs, entitled Coral Reefs in a Changing World: Insights from Extremes, build on the growing body of literature on these unique and important ecosystems, providing a deeper understanding of the patterns and processes governing life in marginal reef systems, and the implications that these insights may have for the future of tropical coral reefs in our rapidly changing world.
Buzova, D, Maugeri, A, Liguori, A, Napodano, C, Lo Re, O, Oben, J, Alisi, A, Gasbarrini, A, Grieco, A, Cerveny, J, Miele, L & Vinciguerra, M 2020, 'Circulating histone signature of human lean metabolic-associated fatty liver disease (MAFLD)', CLINICAL EPIGENETICS, vol. 12, no. 1.
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Camp, EF, Kahlke, T, Nitschke, MR, Varkey, D, Fisher, NL, Fujise, L, Goyen, S, Hughes, DJ, Lawson, CA, Ros, M, Woodcock, S, Xiao, K, Leggat, W & Suggett, DJ 2020, 'Revealing changes in the microbiome of Symbiodiniaceae under thermal stress', ENVIRONMENTAL MICROBIOLOGY, vol. 22, no. 4, pp. 1294-1309.
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Camp, EF, Suggett, DJ, Pogoreutz, C, Nitschke, MR, Houlbreque, F, Hume, BCC, Gardner, SG, Zampighi, M, Rodolfo-Metalpa, R & Voolstra, CR 2020, 'Corals exhibit distinct patterns of microbial reorganisation to thrive in an extreme inshore environment', CORAL REEFS, vol. 39, no. 3, pp. 701-716.
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Carney, RL, Brown, MV, Siboni, N, Raina, J-B, Kahlke, T, Mitrovic, SM & Seymour, JR 2020, 'Highly heterogeneous temporal dynamics in the abundance and diversity of the emerging pathogens Arcobacter at an urban beach', WATER RESEARCH, vol. 171.
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Ceccarelli, DM, McLeod, IM, Boström-Einarsson, L, Bryan, SE, Chartrand, KM, Emslie, MJ, Gibbs, MT, Gonzalez Rivero, M, Hein, MY, Heyward, A, Kenyon, TM, Lewis, BM, Mattocks, N, Newlands, M, Schläppy, M-L, Suggett, DJ & Bay, LK 2020, 'Substrate stabilisation and small structures in coral restoration: State of knowledge, and considerations for management and implementation.', PloS one, vol. 15, no. 10.
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Coral reef ecosystems are under increasing pressure from local and regional stressors and a changing climate. Current management focuses on reducing stressors to allow for natural recovery, but in many areas where coral reefs are damaged, natural recovery can be restricted, delayed or interrupted because of unstable, unconsolidated coral fragments, or rubble. Rubble fields are a natural component of coral reefs, but repeated or high-magnitude disturbances can prevent natural cementation and consolidation processes, so that coral recruits fail to survive. A suite of interventions have been used to target this issue globally, such as using mesh to stabilise rubble, removing the rubble to reveal hard substrate and deploying rocks or other hard substrates over the rubble to facilitate recruit survival. Small, modular structures can be used at multiple scales, with or without attached coral fragments, to create structural complexity and settlement surfaces. However, these can introduce foreign materials to the reef, and a limited understanding of natural recovery processes exists for the potential of this type of active intervention to successfully restore local coral reef structure. This review synthesises available knowledge about the ecological role of coral rubble, natural coral recolonisation and recovery rates and the potential benefits and risks associated with active interventions in this rapidly evolving field. Fundamental knowledge gaps include baseline levels of rubble, the structural complexity of reef habitats in space and time, natural rubble consolidation processes and the risks associated with each intervention method. Any restoration intervention needs to be underpinned by risk assessment, and the decision to repair rubble fields must arise from an understanding of when and where unconsolidated substrate and lack of structure impair natural reef recovery and ecological function. Monitoring is necessary to ascertain the success or failure of the interv...
Clark, JS, Poore, AGB, Coleman, MA & Doblin, MA 2020, 'Local Scale Thermal Environment and Limited Gene Flow Indicates Vulnerability of Warm Edge Populations in a Habitat Forming Macroalga', Frontiers in Marine Science, vol. 7.
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© Copyright © 2020 Clark, Poore, Coleman and Doblin. Species inhabiting warm-edge populations of their distribution are suggested to be at the forefront of global warming due to reduced fitness, limited gene flow and living close to their physiological thermal limits. Determining the scale that governs thermal niche and the functional responses of habitat-forming species to environmental stressors is critical for successful conservation efforts, particularly as coastal ecosystems are impacted by global change. Here, we examine the susceptibility of warm-edge populations to warming, in the habitat-forming macroalga, Hormosira banksii, from south-eastern Australia. We use a quantitative breeding design to quantify intraspecific variation in thermal performance (growth, ontogenic development and photosynthetic efficiency) of different genotypes sourced from sites at the equatorward distributional edge (warm-edge) and those toward the center of its distribution (non-edge). The genetic diversity and structure of H. banksii was also examined using microsatellite markers amongst the same sites. Our results found variable responses in thermal performance for growth and development. Warm-edge germlings grew optimally in lower temperatures tested and had narrower thermal breadth compared to non-edge germlings which grew in higher and more broader temperatures. Warm-edge germlings however, showed greater plasticity to tolerate high light indicated by a greater proportion of energy being dissipated as regulated non-photochemical quenching [Y(NPQ)] than non-regulated non-photochemical quenching [Y(NO)]. Overall genetic diversity was lower at the warm-edge location with evidence of increased structuring and reduced gene flow in comparison to the non-edge location. Evidence of genetic structuring was not found locally between high and low shore within sites. Together, these data suggest that non-edge populations may be “thermally buffered” from increased temperatures associated...
Clerc, EE, Raina, J-B, Lambert, BS, Seymour, J & Stocker, R 2020, 'In Situ Chemotaxis Assay to Examine Microbial Behavior in Aquatic Ecosystems', JOVE-JOURNAL OF VISUALIZED EXPERIMENTS, no. 159.
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Clifton, J, Osman, EO, Suggett, DJ & Smith, DJ 2020, 'Resolving conservation and development tensions in a small island state: A governance analysis of Curieuse Marine National Park, Seychelles', Marine Policy.
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© 2019 Elsevier Ltd The management and conservation of marine resources in Seychelles, a small island developing state (SIDS) in the western Indian Ocean, is fundamental to maintaining the flow of international visitors which forms the mainstay of the nation's economy. There is an increasing trend towards empowering non-governmental organisations and parastatal entities with protected area management responsibilities, which partly reflects the chronic underfunding of the state protected area management institution. This paper explores these and related issues through a governance analysis of Curieuse Marine National Park, which is the most popular state-owned marine national park in terms of recorded visitor numbers. This demonstrates that the inability to implement economic incentives through not fully capitalising on the use and non-use values of the park has deleterious consequences for managing the combined impacts of tourism and fisheries on the ecological assets of the park. Furthermore, the capacity of the state management institution is being eroded through a focus on the development of an extensive network of new marine protected areas under the direction of an international non-governmental organisation. Suggestions are made that could strengthen economic, participative and interpretative incentives to provide a more sustainable basis for marine national park management.
Clifton, J, Osman, EO, Suggett, DJ & Smith, DJ 2020, 'Resolving conservation and development tensions in a small island state: A governance analysis of Curieuse Marine National Park, Seychelles', Marine Policy, pp. 103650-103650.
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Collins, S, Boyd, PW & Doblin, MA 2020, 'Evolution, Microbes, and Changing Ocean Conditions', ANNUAL REVIEW OF MARINE SCIENCE, VOL 12, vol. 12, pp. 181-208.
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Commault, AS, Walia, NK, Fabris, M, Barolo, L, Siboni, N, Adriaans, J, Ralph, PJ & Pernice, M 2020, 'Effect of biphasic temperature regime on therapeutic recombinant protein production in the green alga Chlamydomonas reinhardtii', ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, vol. 50.
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Ding, Y, Zhang, H, Wang, Z, Xie, Q, Wang, Y, Liu, L & Hall, CC 2020, 'A Comparison of Estimating Crop Residue Cover from Sentinel-2 Data Using Empirical Regressions and Machine Learning Methods', REMOTE SENSING, vol. 12, no. 9.
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Drapela, S, Khirsariya, P, van Weerden, WM, Fedr, R, Suchankova, T, Buzova, D, Cerveny, J, Hampl, A, Puhr, M, Watson, WR, Culig, Z, Krejci, L, Paruch, K & Soucek, K 2020, 'The CHK1 inhibitor MU380 significantly increases the sensitivity of human docetaxel-resistant prostate cancer cells to gemcitabine through the induction of mitotic catastrophe', MOLECULAR ONCOLOGY.
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Fabris, M, Abbriano, RM, Pernice, M, Sutherland, DL, Commault, AS, Hall, CC, Labeeuw, L, McCauley, J, Kuzhiuparambil, U, Ray, P, Kahlke, T & Ralph, PJ 2020, 'Emerging Technologies in Algal Biotechnology: Toward the Establishment of a Sustainable, Algae-Based Bioeconomy', FRONTIERS IN PLANT SCIENCE, vol. 11.
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Fabris, M, George, J, Kuzhiumparambil, U, Lawson, CA, Jaramillo-Madrid, AC, Abbriano, RM, Vickers, CE & Ralph, P 2020, 'Extrachromosomal Genetic Engineering of the Marine Diatom Phaeodactylum tricornutum Enables the Heterologous Production of Monoterpenoids', ACS SYNTHETIC BIOLOGY, vol. 9, no. 3, pp. 598-612.
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Fisher, NL, Campbell, DA, Hughes, DJ, Kuzhiumparambil, U, Halsey, KH, Ralph, PJ & Suggett, DJ 2020, 'Divergence of photosynthetic strategies amongst marine diatoms.', PloS one, vol. 15, no. 12, p. e0244252.
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Marine phytoplankton, and in particular diatoms, are responsible for almost half of all primary production on Earth. Diatom species thrive from polar to tropical waters and across light environments that are highly complex to relatively benign, and so have evolved highly divergent strategies for regulating light capture and utilization. It is increasingly well established that diatoms have achieved such successful ecosystem dominance by regulating excitation energy available for generating photosynthetic energy via highly flexible light harvesting strategies. However, how different light harvesting strategies and downstream pathways for oxygen production and consumption interact to balance excitation pressure remains unknown. We therefore examined the responses of three diatom taxa adapted to inherently different light climates (estuarine Thalassioisira weissflogii, coastal Thalassiosira pseudonana and oceanic Thalassiosira oceanica) during transient shifts from a moderate to high growth irradiance (85 to 1200 μmol photons m-2 s-1). Transient high light exposure caused T. weissflogii to rapidly downregulate PSII with substantial nonphotochemical quenching, protecting PSII from inactivation or damage, and obviating the need for induction of O2 consuming (light-dependent respiration, LDR) pathways. In contrast, T. oceanica retained high excitation pressure on PSII, but with little change in RCII photochemical turnover, thereby requiring moderate repair activity and greater reliance on LDR. T. pseudonana exhibited an intermediate response compared to the other two diatom species, exhibiting some downregulation and inactivation of PSII, but high repair of PSII and induction of reversible PSII nonphotochemical quenching, with some LDR. Together, these data demonstrate a range of strategies for balancing light harvesting and utilization across diatom species, which reflect their adaptation to sustain photosynthesis under environments with inherently different light reg...
Fleck, R, Gill, RL, Pettit, T, Irga, PJ, Williams, NLR, Seymour, JR & Torpy, FR 2020, 'Characterisation of fungal and bacterial dynamics in an active green wall used for indoor air pollutant removal', BUILDING AND ENVIRONMENT, vol. 179.
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Focardi, A, Ostrowski, M, Goossen, K, Brown, M & Paulsen, I 2020, 'Investigating the Diversity of Marine Bacteriophage in Contrasting Water Masses Associated with the East Australian Current (EAC) System', VIRUSES-BASEL, vol. 12, no. 3.
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Fujise, L, Suggett, DJ, Stat, M, Kahlke, T, Bunce, M, Gardner, SG, Goyen, S, Woodcock, S, Ralph, PJ, Seymour, JR, Siboni, N & Nitschke, MR 2020, 'Unlocking the phylogenetic diversity, primary habitats, and abundances of free-living Symbiodiniaceae on a coral reef.', Molecular ecology.
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Dinoflagellates of the family Symbiodiniaceae form mutualistic symbioses with marine invertebrates such as reef-building corals, but also inhabit reef environments as free-living cells. Most coral species acquire Symbiodiniaceae horizontally from the surrounding environment during the larval and/or recruitment phase, however the phylogenetic diversity and ecology of free-living Symbiodiniaceae on coral reefs is largely unknown. We coupled environmental DNA sequencing and genus-specific qPCR to resolve the community structure and cell abundances of free-living Symbiodiniaceae in the water column, sediment, and macroalgae and compared these to coral symbionts. Sampling was conducted at two time points, one of which coincided with the annual coral spawning event when recombination between hosts and free-living Symbiodiniaceae is assumed to be critical. Amplicons of the internal transcribed spacer (ITS2) region were assigned to 12 of the 15 Symbiodiniaceae genera or genera-equivalent lineages. Community compositions were separated by habitat, with water samples containing a high proportion of sequences corresponding to coral symbionts of the genus Cladocopium, potentially as a result of cell expulsion from in hospite populations. Sediment-associated Symbiodiniaceae communities were distinct, potentially due to the presence of exclusively free-living species. Intriguingly, macroalgal surfaces displayed the highest cell abundances of Symbiodiniaceae, suggesting a key role for macroalgae in ensuring the ecological success of corals through maintenance of a continuum between environmental and symbiotic populations of Symbiodiniaceae.
Gao, C, Fernandez, VI, Lee, KS, Fenizia, S, Pohnert, G, Seymour, JR, Raina, J-B & Stocker, R 2020, 'Single-cell bacterial transcription measurements reveal the importance of dimethylsulfoniopropionate (DMSP) hotspots in ocean sulfur cycling.', Nature communications, vol. 11, no. 1.
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Dimethylsulfoniopropionate (DMSP) is a pivotal compound in marine biogeochemical cycles and a key chemical currency in microbial interactions. Marine bacteria transform DMSP via two competing pathways with considerably different biogeochemical implications: demethylation channels sulfur into the microbial food web, whereas cleavage releases sulfur into the atmosphere. Here, we present single-cell measurements of the expression of these two pathways using engineered fluorescent reporter strains of Ruegeria pomeroyi DSS-3, and find that external DMSP concentration dictates the relative expression of the two pathways. DMSP induces an upregulation of both pathways, but only at high concentrations (>1 μM for demethylation; >35 nM for cleavage), characteristic of microscale hotspots such as the vicinity of phytoplankton cells. Co-incubations between DMSP-producing microalgae and bacteria revealed an increase in cleavage pathway expression close to the microalgae's surface. These results indicate that bacterial utilization of microscale DMSP hotspots is an important determinant of the fate of sulfur in the ocean.
George, J, Kahlke, T, Abbriano, RM, Kuzhiumparambil, U, Ralph, PJ & Fabris, M 2020, 'Metabolic Engineering Strategies in Diatoms Reveal Unique Phenotypes and Genetic Configurations With Implications for Algal Genetics and Synthetic Biology', FRONTIERS IN BIOENGINEERING AND BIOTECHNOLOGY, vol. 8.
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Hughes, DJ, Alderdice, R, Cooney, C, Kuehl, M, Pernice, M, Voolstra, CR & Suggett, DJ 2020, 'Coral reef survival under accelerating ocean deoxygenation', NATURE CLIMATE CHANGE, vol. 10, no. 4, pp. 296-307.
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Hughes, DJ, Crosswell, JR, Doblin, MA, Oxborough, K, Ralph, PJ, Varkey, D & Suggett, DJ 2020, 'Dynamic variability of the phytoplankton electron requirement for carbon fixation in eastern Australian waters', Journal of Marine Systems, vol. 202.
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© 2019 Elsevier B.V. Fast Repetition Rate fluorometry (FRRf) generates high-resolution measures of phytoplankton primary productivity as electron transport rates (ETRs). How ETRs scale to corresponding inorganic carbon (C) uptake rates (the so-called electron requirement for carbon fixation, Φe,C), inherently describes the extent and effectiveness with which absorbed light energy drives C-fixation. However, it remains unclear whether and how Φe,C follows predictable patterns for oceanographic datasets spanning physically dynamic, and complex, environmental gradients. We utilise a unique high-throughput approach, coupling ETRs and 14C-incubations to produce a semi-continuous dataset of Φe,C (n = 80), predominantly from surface waters, along the Australian coast (Brisbane to the Tasman Sea), including the East Australian Current (EAC). Environmental conditions along this transect could be generally grouped into cooler, more nutrient-rich waters dominated by larger size-fractionated Chl-a (>10 μm) versus warmer nutrient-poorer waters dominated by smaller size-fractionated Chl-a (<2 μm). Whilst Φe,C was higher for warmer water samples, environmental conditions alone explained <20% variance of Φe,C, and changes in predominant size-fraction(s) distributions of Chl-a (biomass) failed to explain variance of Φe,C. Instead, normalised Stern-Volmer non-photochemical quenching (NPQNSV = F0′/Fv′) was a better predictor of Φe,C, explaining ~55% of observed variability. NPQNSV is a physiological descriptor that accounts for changes in both long-term driven acclimation in non-radiative decay, and quasi-instantaneous PSII downregulation, and thus may prove a useful predictor of Φe,C across physically-dynamic regimes, provided the slope describing their relationship is predictable. We also consider recent advances in fluorescence-based corrections to evaluate the potential role of baseline fluorescence (Fb) in contributing to overestimation of Φe,C and the correlation between Φe,C...
Hughes, DJ, Giannini, FC, Ciotti, AM, Doblin, MA, Ralph, PJ, Varkey, D, Verma, A & Suggett, DJ 2020, 'Taxonomic Variability in the Electron Requirement for Carbon Fixation Across Marine Phytoplankton.', Journal of phycology.
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Fast Repetition Rate fluorometry (FRRf) has been increasingly used to measure marine primary productivity by oceanographers to understand how carbon (C) uptake patterns vary over space and time in the global ocean. As FRRf measures electron transport rates through photosystem II (ETRPSII ), a critical, but difficult to predict conversion factor termed the "electron requirement for carbon fixation" (Φe,C ) is needed to scale ETRPSII to C-fixation rates. Recent studies have generally focused on understanding environmental regulation of Φe,C , while taxonomic control has been explored by only a handful of laboratory studies encompassing a limited diversity of phytoplankton species. We therefore assessed Φe,C for a wide range of marine phytoplankton (n = 17 strains) spanning multiple taxonomic and size classes. Data mined from previous studies were further considered to determine whether Φe,C variability could be explained by taxonomy versus other phenotypic traits influencing growth and physiological performance (e.g., cell size). We found that Φe,C exhibited considerable variability (~4-10 mol e- · [mol C]-1 ) and was negatively correlated with growth rate (R2 = 0.7, P < 0.01). Diatoms exhibited a lower Φe,C compared to chlorophytes during steady-state, nutrient-replete growth. Inclusion of meta-analysis data did not find significant relationships between Φe,C and class, or growth rate, although confounding factors inherent to methodological inconsistencies between studies likely contributed to this. Knowledge of empirical relationships between Φe,C and growth rate coupled with recent improvements in quantifying phytoplankton growth rates in situ, facilitate up-scaling of FRRf campaigns to routinely derive Φe,C needed to assess ocean C-cycling.
Hurtado McCormick, V, Kahlke, T, Krix, D, Larkum, A, Ralph, PJ & Seymour, JR 2020, 'Seagrass leaf reddening alters the microbiome of Zostera muelleri', Marine Ecology Progress Series, vol. 646, pp. 29-44.
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© Inter-Research 2020 · www.int-res.com Seagrasses host an extremely diverse microbiome that plays fundamental roles in seagrass health and productivity but may be sensitive to shifts in host physiology. Here, we observed a leaf reddening phenomenon in Zostera muelleri and characterized bacterial assemblages associated with green and reddened leaves to determine whether this change in leaf pigmentation stimulates shifts in the seagrass microbiome. Using 16S rRNA gene amplicon sequencing, we observed that the microbiome associated with 4 different leaf pigmentation categories (i.e. green, white, purple and black) differed significantly, with substantial changes in microbiome composition when the tissue is whitened (non-pigmented). Actinobacteria, Rhodobacteraceae, Erythrobacter, Sulfitobacter and Granulosicoccus were enriched in black and/or purple tissues and discriminated these microbiomes from those associated with green leaves. Contrastingly, all 'discriminatory' zero-radius operational taxonomic units (zOTUs) were depleted within the communities associated with white samples. While 40% of the abundant zOTUs identified were exclusively associated with a single pigmentation category, only 3% were shared across all categories, indicating partitioning of the phyllosphere microbiome. However, a significant proportion of the 'normal' (green) leaf core microbiome was also retained in the core communities associated with black (70%) and purple (70%) tissues. Contrastingly, no core zOTUs were maintained in the white tissues. These results indicate that environmentally driven physiological shifts in seagrasses, such as leaf reddening expressed in response to high irradiance, can impact the seagrass leaf microbiome, resulting in significant shifts in the microbiome of reddened leaves with the most extreme expression (in white tissue of reddened leaves).
Iermak, I, Szabo, M & Zavafer, A 2020, 'Analysis of OJIP transients during photoinactivation of photosystem II indicates the presence of multiple photosensitizers in vivo and in vitro', PHOTOSYNTHETICA, vol. 58, no. 2, pp. 497-506.
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Jaramillo Madrid, A, Abbriano, R, Ashworth, J, Fabris, M, Pernice, M & Ralph, PJ 2020, 'Overexpression of Key Sterol Pathway Enzymes in Two Model Marine Diatoms Alters Sterol Profiles in Phaeodactylum tricornutum.', Pharmaceuticals (Basel, Switzerland), vol. 13, no. 12.
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Sterols are a class of triterpenoid molecules with diverse functional roles in eukaryotic cells, including intracellular signaling and regulation of cell membrane fluidity. Diatoms are a dominant eukaryotic phytoplankton group that produce a wide diversity of sterol compounds. The enzymes 3-hydroxy-3-methyl glutaryl CoA reductase (HMGR) and squalene epoxidase (SQE) have been reported to be rate-limiting steps in sterol biosynthesis in other model eukaryotes; however, the extent to which these enzymes regulate triterpenoid production in diatoms is not known. To probe the role of these two metabolic nodes in the regulation of sterol metabolic flux in diatoms, we independently over-expressed two versions of the native HMGR and a conventional, heterologous SQE gene in the diatoms Thalassiosira pseudonana and Phaeodactylum tricornutum. Overexpression of these key enzymes resulted in significant differential accumulation of downstream sterol pathway intermediates in P. tricornutum. HMGR-mVenus overexpression resulted in the accumulation of squalene, cycloartenol, and obtusifoliol, while cycloartenol and obtusifoliol accumulated in response to heterologous NoSQE-mVenus overexpression. In addition, accumulation of the end-point sterol 24-methylenecholesta-5,24(24')-dien-3β-ol was observed in all P. tricornutum overexpression lines, and campesterol increased three-fold in P. tricornutum lines expressing NoSQE-mVenus. Minor differences in end-point sterol composition were also found in T. pseudonana, but no accumulation of sterol pathway intermediates was observed. Despite the successful manipulation of pathway intermediates and individual sterols in P. tricornutum, total sterol levels did not change significantly in transformed lines, suggesting the existence of tight pathway regulation to maintain total sterol content.
Jaramillo Madrid, A, Ashworth, J, Fabris, M & Ralph, PJ 2020, 'The unique sterol biosynthesis pathway of three model diatoms consists of a conserved core and diversified endpoints', Algal Research, vol. 48.
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© 2020 Diatoms produce a wide diversity of sterols among different species, the biosynthesis and conservation of which is not yet fully understood. To investigate the conservation and divergence of sterol biosynthesis pathways among diatoms, we performed comparative metabolic profiling and transcriptomics for a centric diatom (Thalassiosira pseudonana), a pennate diatom (Phaeodactylum tricornutum) and a chaetocerid (Chaetoceros muelleri) in response to inhibitors of enzymes involved in sterol biosynthesis. These three model diatoms, which are representative of distinct clades, share a unique core phytosterol biosynthesis pathway that relies on a terbinafine-insensitive alternative squalene epoxidase and the cyclization of 2,3-epoxysqualene into cycloartenol by a conserved oxidosqualene cyclase. Lineage-specific divergence in the synthesis of sterol precursors was found in the species analyzed. Cholesterol synthesis in diatoms seems to occur via cycloartenol rather than lanosterol. The diversification of natural sterols produced by each species appears to occur downstream of all experimentally targeted enzymes, suggesting adaptive specialization in terminal synthesis pathways.
Jaramillo-Madrid, AC, Ashworth, J & Ralph, PJ 2020, 'Levels of Diatom Minor Sterols Respond to Changes in Temperature and Salinity', JOURNAL OF MARINE SCIENCE AND ENGINEERING, vol. 8, no. 2.
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King, WL, Siboni, N, Kahlke, T, Dove, M, O'Connor, W, Mahbub, KR, Jenkins, C, Seymour, JR & Labbate, M 2020, 'Regional and oyster microenvironmental scale heterogeneity in the Pacific oyster bacterial community', FEMS MICROBIOLOGY ECOLOGY, vol. 96, no. 5.
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Kuhl, M, Trampe, E, Mosshammer, M, Johnson, M, Larkum, AWD, Frigaard, N-U & Koren, K 2020, 'Substantial near-infrared radiation-driven photosynthesis of chlorophyll f-containing cyanobacteria in a natural habitat', ELIFE, vol. 9.
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Kulk, G, Platt, T, Dingle, J, Jackson, T, Joensson, BF, Bouman, HA, Babin, M, Brewin, RJW, Doblin, M, Estrada, M, Figueiras, FG, Furuya, K, Gonzalez-Benitez, N, Gudfinnsson, HG, Gudmundsson, K, Huang, B, Isada, T, Kovac, Z, Lutz, VA, Maranon, E, Raman, M, Richardson, K, Rozema, PD, van de Poll, WH, Segura, V, Tilstone, GH, Uitz, J, van Dongen-Vogels, V, Yoshikawa, T & Sathyendranath, S 2020, 'Primary Production, an Index of Climate Change in the Ocean: Satellite-Based Estimates over Two Decades', REMOTE SENSING, vol. 12, no. 5.
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Lampignano, R, Neumann, MHD, Weber, S, Kloten, V, Herdean, A, Voss, T, Groelz, D, Babayan, A, Tibbesma, M, Schlumpberger, M, Chemi, F, Rothwell, DG, Wikman, H, Galizzi, J-P, Bergheim, IR, Russnes, H, Mussolin, B, Bonin, S, Voigt, C, Musa, H, Pinzani, P, Lianidou, E, Brady, G, Speicher, MR, Pantel, K, Betsou, F, Schuuring, E, Kubista, M, Ammerlaan, W, Sprenger-Haussels, M, Schlange, T & Heitzer, E 2020, 'Multicenter Evaluation of Circulating Cell-Free DNA Extraction and Downstream Analyses for the Development of Standardized (Pre) analytical Work Flows', CLINICAL CHEMISTRY, vol. 66, no. 1, pp. 149-160.
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Lawson, CA, Raina, J-B, Deschaseaux, E, Hrebien, V, Possell, M, Seymour, JR & Suggett, DJ 2020, 'Heat stress decreases the diversity, abundance and functional potential of coral gas emissions', GLOBAL CHANGE BIOLOGY, vol. 27, no. 4, pp. 879-891.
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Lawson, CA, Seymour, JR, Possell, M, Suggett, DJ & Raina, JB 2020, 'The Volatilomes of Symbiodiniaceae-Associated Bacteria Are Influenced by Chemicals Derived From Their Algal Partner', Frontiers in Marine Science, vol. 7.
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© Copyright © 2020 Lawson, Seymour, Possell, Suggett and Raina. Biogenic volatile organic compounds (BVOCs) are a large group of molecules involved in trophic interactions, stress response and atmospheric chemistry. Although they have been extensively studied in terrestrial ecosystems, their identity and prevalence in the marine environment remains largely unexplored. Here we characterized the volatilome of two abundant marine bacteria that were previously identified as members of the core microbiome of Symbiodiniaceae (phylum: Dinoflagellata), the photosynthetic endosymbionts of reef building corals. To determine the influence of Symbiodiniaceae exudate on their associated bacteria, we incubated isolates of Marinobacter adhaerens HP15 and Labrenzia sp. 21p with Symbiodiniaceae culture filtrate or culture medium (control) and investigated their volatilomes using GC–MS. The volatilome of Labrenzia sp. incubated in Symbiodiniaceae filtrate was significantly different and more diverse relative to the control. In contrast, the overall composition of the M. adhaerens volatilomes were consistent between treatment and control. Among the 35 compounds detected in both bacterial species, the dominant chemical functional groups were halogenated hydrocarbons, aromatic hydrocarbons and organosulfurs, some of which are known to play roles in inter-organism signaling, to act as antioxidants and as antimicrobials. This study provides new insights into the potential sources and diversity of marine BVOCs, uncovering a wide range of molecules that may play important physiological and ecological roles for these organisms, while also revealing the role of Symbiodiniaceae-associated bacteria in the emission of important atmospheric gases.
Liu, P-C, Peacock, WJ, Wang, L, Furbank, R, Larkum, A & Dennis, ES 2020, 'Leaf growth in early development is key to biomass heterosis in Arabidopsis', JOURNAL OF EXPERIMENTAL BOTANY, vol. 71, no. 8, pp. 2439-2450.
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Mahbub, KR, King, WL, Siboni, N, Nguyen, VK, Rahman, MM, Megharaj, M, Seymour, JR, Franks, AE & Labbate, M 2020, 'Long-lasting effect of mercury contamination on the soil microbiota and its co-selection of antibiotic resistance', Environmental Pollution, vol. 265.
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© 2020 Elsevier Ltd Mercury can drive co-selection of antibiotic resistance genes in non-agricultural soils. The co-selection process is linked with soil properties, mercury content and soil microbiota shift.
Matthews, JL, Raina, J-B, Kahlke, T, Seymour, JR, van Oppen, MJH & Suggett, DJ 2020, 'Symbiodiniaceae-bacteria interactions: rethinking metabolite exchange in reef-building corals as multi-partner metabolic networks', ENVIRONMENTAL MICROBIOLOGY, vol. 22, no. 5, pp. 1675-1687.
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McCauley, JI, Labeeuw, L, Jaramillo Madrid, A, Nguyen, LN, Nghiem, LD, Chaves, AV & Ralph, PJ 2020, 'Management of Enteric Methanogenesis in Ruminants by Algal-Derived Feed Additives', Current Pollution Reports, vol. 6, no. 3, pp. 188-205.
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© 2020, Springer Nature Switzerland AG. Purpose of Review: In this paper, we critically review the current state of nutritional management strategies to reduce methane emissions resulting from enteric fermentation in livestock production. In this context, it highlights the novel strategy regarding the use of macroalgal- and microalgal-derived feed additives. Recent Findings: Several feed management strategies for ruminants focus on the inclusion of nutritional supplements, increasing proportion of starch, or supplementation with high-energy lipids. These strategies aim to improve animal productivity, whilst at the same time reduce methane emissions. Algae supplements are currently investigated as novel ingredients for decreasing methanogenesis, with the potential production of algal biomass also contributing to reducing greenhouse gas emissions. Thus, utilisation of algal biomass as a feed concentrate in dietary supplementation presents a sustainable and environmentally friendly strategy. Summary: This review summarises the current stage of research on dietary strategies and their influences on the metabolic processes during enteric fermentation. This information is essential for developing strategies to mitigate methane emissions in the livestock industry. We specifically present the opportunities that algae could offer as a feed additive for methanogenic reduction in cattle. The data compiled from the peer-reviewed literature revealed synergistic effects of algal biomass on methane reduction and animal productivity. However, the challenges regarding the mass cultivation of macro- and microalgae were noticed. Considering the diversity of algal species, future research should increase screening efforts to include more species and dosage evaluation, along with efforts to see if such effects are sustained over time.
Messer, LF, Ostrowski, M, Doblin, MA, Petrou, K, Baird, ME, Ingleton, T, Bissett, A, Van de Kamp, J, Nelson, T, Paulsen, I, Bodrossy, L, Fuhrman, JA, Seymour, JR & Brown, MV 2020, 'Microbial tropicalization driven by a strengthening western ocean boundary current.', Global change biology, vol. 26, no. 10, pp. 5613-5629.
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Western boundary currents (WBCs) redistribute heat and oligotrophic seawater from the tropics to temperate latitudes, with several displaying substantial climate change-driven intensification over the last century. Strengthening WBCs have been implicated in the poleward range expansion of marine macroflora and fauna, however, the impacts on the structure and function of temperate microbial communities are largely unknown. Here we show that the major subtropical WBC of the South Pacific Ocean, the East Australian Current (EAC), transports microbial assemblages that maintain tropical and oligotrophic (k-strategist) signatures, to seasonally displace more copiotrophic (r-strategist) temperate microbial populations within temperate latitudes of the Tasman Sea. We identified specific characteristics of EAC microbial assemblages compared with non-EAC assemblages, including strain transitions within the SAR11 clade, enrichment of Prochlorococcus, predicted smaller genome sizes and shifts in the importance of several functional genes, including those associated with cyanobacterial photosynthesis, secondary metabolism and fatty acid and lipid transport. At a temperate time-series site in the Tasman Sea, we observed significant reductions in standing stocks of total carbon and chlorophyll a, and a shift towards smaller phytoplankton and carnivorous copepods, associated with the seasonal impact of the EAC microbial assemblage. In light of the substantial shifts in microbial assemblage structure and function associated with the EAC, we conclude that climate-driven expansions of WBCs will expand the range of tropical oligotrophic microbes, and potentially profoundly impact the trophic status of temperate waters.
Miller, AD, Coleman, MA, Clark, J, Cook, R, Naga, Z, Doblin, MA, Hoffmann, AA, Sherman, CDH & Bellgrove, A 2020, 'Local thermal adaptation and limited gene flow constrain future climate responses of a marine ecosystem engineer', EVOLUTIONARY APPLICATIONS, vol. 13, no. 5, pp. 918-934.
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Murray, JS, Nishimura, T, Finch, SC, Rhodes, LL, Puddick, J, Harwood, DT, Larsson, ME, Doblin, MA, Leung, P, Yan, M, Rise, F, Wilkins, AL & Prinsep, MR 2020, 'The role of 44-methylgambierone in ciguatera fish poisoning: Acute toxicity, production by marine microalgae and its potential as a biomarker for Gambierdiscus spp.', Harmful algae, vol. 97.
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Ciguatera fish poisoning (CFP) is prevalent around the tropical and sub-tropical latitudes of the world and impacts many Pacific island communities intrinsically linked to the reef system for sustenance and trade. While the genus Gambierdiscus has been linked with CFP, it is commonly found on tropical reef systems in microalgal assemblages with other genera of toxin-producing, epiphytic and/or benthic dinoflagellates - Amphidinium, Coolia, Fukuyoa, Ostreopsis and Prorocentrum. Identifying a biomarker compound that can be used for the early detection of Gambierdiscus blooms, specifically in a mixed microalgal community, is paramount in enabling the development of management and mitigation strategies. Following on from the recent structural elucidation of 44-methylgambierone, its potential to contribute to CFP intoxication events and applicability as a biomarker compound for Gambierdiscus spp. was investigated. The acute toxicity of this secondary metabolite was determined by intraperitoneal injection using mice, which showed it to be of low toxicity, with an LD50 between 20 and 38 mg kg-1. The production of 44-methylgambierone by 252 marine microalgal isolates consisting of 90 species from 32 genera across seven classes, was assessed by liquid chromatography-tandem mass spectrometry. It was discovered that the production of this secondary metabolite was ubiquitous to the eight Gambierdiscus species tested, however not all isolates of G. carpenteri, and some species/isolates of Coolia and Fukuyoa.
Najafpour, MM, Zaharieva, I, Zand, Z, Maedeh Hosseini, S, Kouzmanova, M, Hołyńska, M, Tranca, I, Larkum, AW, Shen, JR & Allakhverdiev, SI 2020, 'Water-oxidizing complex in Photosystem II: Its structure and relation to manganese-oxide based catalysts', Coordination Chemistry Reviews, vol. 409.
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© 2020 Elsevier B.V. Cyanobacteria, green algae, and higher plants provide the major part of molecular O2 of Earth atmosphere via water oxidation of oxygenic photosynthesis. The water-oxidizing complex is a manganese-calcium oxide-based cluster embedded in Photosystem II that oxidizes water with high turnover frequency. The atomic structure and analysis of the Mn-Ca cluster are important in understanding the mechanism of water oxidation and for the design of efficient artificial water-oxidizing catalysts. With this short review, we aim to introduce the basic features of the biological water oxidation to the new-comers in the field. Taking into account the recent structural studies, including a high-resolution, radiation-damage-free structure of the water-oxidizing complex, and structures of intermediate S-states revealed by femtosecond X-ray free electron lasers, we discuss the structure and functions of the biologically active site and its implications for the development of inorganic catalysts for solar fuels production.
Nguyen, HM, Kim, M, Ralph, PJ, Marín-Guirao, L, Pernice, M & Procaccini, G 2020, 'Stress Memory in Seagrasses: First Insight Into the Effects of Thermal Priming and the Role of Epigenetic Modifications.', Frontiers in plant science, vol. 11.
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While thermal priming and the relative role of epigenetic modifications have been widely studied in terrestrial plants, their roles remain unexplored in seagrasses so far. Here, we experimentally compared the ability of two different functional types of seagrass species, dominant in the Southern hemisphere, climax species Posidonia australis and pioneer species Zostera muelleri, to acquire thermal-stress memory to better survive successive stressful thermal events. To this end, a two-heatwave experimental design was conducted in a mesocosm setup. Findings across levels of biological organization including the molecular (gene expression), physiological (photosynthetic performances and pigments content) and organismal (growth) levels provided the first evidence of thermal priming in seagrasses. Non-preheated plants suffered a significant reduction in photosynthetic capacity, leaf growth and chlorophyll a content, while preheated plants were able to cope better with the recurrent stressful event. Gene expression results demonstrated significant regulation of methylation-related genes in response to thermal stress, suggesting that epigenetic modifications could play a central role in seagrass thermal stress memory. In addition, we revealed some interspecific differences in thermal responses between the two different functional types of seagrass species. These results provide the first insights into thermal priming and relative epigenetic modifications in seagrasses paving the way for more comprehensive forecasting and management of thermal stress in these marine foundation species in an era of rapid environmental change.
Nguyen, LN, Commault, AS, Kahlke, T, Ralph, PJ, Semblante, GU, Johir, MAH & Nghiem, LD 2020, 'Genome sequencing as a new window into the microbial community of membrane bioreactors - A critical review.', Science of the Total Environment, vol. 704.
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Recent developed sequencing techniques have resulted in a new and unprecedented way to study biological wastewater treatment, in which most organisms are uncultivable. This review provides (i) an insight on state-of-the-art sequencing techniques and their limitations; (ii) a critical assessment of the microbial community in biological reactor and biofouling layer in a membrane bioreactor (MBR). The data from high-throughput sequencing has been used to infer microbial growth conditions and metabolisms of microorganisms present in MBRs at the time of sampling. These data shed new insight to two fundamental questions about a microbial community in the MBR process namely the microbial composition (who are they?) and the functions of each specific microbial assemblage (what are their function?). The results to date also highlight the complexity of the microbial community growing on MBRs. Environmental conditions are dynamic and diverse, and can influence the diversity and structural dynamics of any given microbial community for wastewater treatment. The benefits of understanding the structure of microbial communities on three major aspects of the MBR process (i.e. nutrient removal, biofouling control, and micropollutant removal) were symmetrically delineated. This review also indicates that the deployment of microbial community analysis for a practical engineering context, in terms of process design and system optimization, can be further realized.
Nguyen, LN, Kumar, J, Vu, MT, Mohammed, JAH, Pathak, N, Commault, AS, Sutherland, D, Zdarta, J, Tyagi, VK & Nghiem, LD 2020, 'Biomethane production from anaerobic co-digestion at wastewater treatment plants: A critical review on development and innovations in biogas upgrading techniques', Science of the Total Environment.
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© 2020 Elsevier B.V. Anaerobic co-digestion (AcoD) can utilise spare digestion capacity at existing wastewater treatment plants (WWTP) to generate surplus biogas beyond the plant's internal energy requirement. Data from industry reports and the peer-reviewed literature show that through AcoD, numerous examples of WWTPs have become net energy producers, necessitating other high-value applications for surplus biogas. A globally emerging trend is to upgrade biogas to biomethane, which can then be used as town gas or transport fuel. Water, organic solvent and chemical scrubbing, pressure swing adsorption, membrane separation, and cryogenic technology are commercially available CO2 removal technologies for biogas upgrade. Although water scrubbing is currently the most widely applied technology due to low capital and operation cost, significant market growth in membrane separation has been seen over the 2015–2019 period. Further progress in materials engineering and sciences is expected and will further enhance the membrane separation competitiveness for biogas upgrading. Several emerging biotechnologies to i) improve biogas quality from AcoD; ii) accelerate the absorption rate, and iii) captures CO2 in microalgal culture have also been examined and discussed in this review. Through a combination of AcoD and biogas upgrade, more WWTPs are expected to become net energy producers.
Nguyen, LN, Truong, MV, Nguyen, AQ, Johir, MAH, Commault, AS, Ralph, PJ, Semblante, GU & Nghiem, LD 2020, 'A sequential membrane bioreactor followed by a membrane microalgal reactor for nutrient removal and algal biomass production', Environmental Science: Water Research and Technology, vol. 6, no. 1, pp. 189-196.
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© 2019 The Royal Society of Chemistry. A hybrid process combining a single compartment aerobic membrane bioreactor (MBR) and a membrane microalgal reactor (MMR) was evaluated for nutrient removal and microalgal biomass production. When operated without biomass extraction, the microalgal biomass in the MMR reached 920 mg L-1 on day 18 and then collapsed, rendering nutrient removal ineffective. Stable operation of the MMR was achieved by regular biomass extraction (i.e. 1/30 of the microalgal biomass in the reactor daily). The biomass production at steady state was approximately 26 g m-3 d-1. The NO3- and PO43- uptake values by microalgae were 4.0 ± 1.1 and 1.5 ± 0.9 g m-3 d-1, respectively. A facile flocculation and separation technique capable of recovering 98% microalgal biomass was demonstrated. Although the hybrid process can significantly enhance nutrient removal and biomass production, further research is needed to intensify the microalgal growth rate. At the current microalgal growth rate, a large MMR volume (37 times that of the MBR) is necessary for synchronous operation.
Nitschke, MR, Craveiro, SC, Brandão, C, Fidalgo, C, Serôdio, J, Calado, AJ & Frommlet, JC 2020, 'Description of Freudenthalidium gen. nov. and Halluxium gen. nov. to Formally Recognize Clades Fr3 and H as Genera in the Family Symbiodiniaceae (Dinophyceae)', Journal of Phycology, vol. 56, no. 4, pp. 923-940.
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© 2020 Phycological Society of America The Symbiodiniaceae are a family of marine dinoflagellates known mostly for their endosymbiotic interactions with invertebrates and protists, but facultatively and exclusively free-living life histories in this family are also evident. A recent systematic revision of the Symbiodiniaceae replaced the clade-based nomenclature of seven divergent lineages of “Symbiodinium” sensu lato with one based on formally described genera. The revised taxonomy was not extended to the whole group because type species to describe a new genus for each of the remaining clades and subclades were lacking. In an effort to characterize benthic habitats of symbiodiniaceans in sediments at Heron Island (Great Barrier Reef, Australia), we isolated >100 monoclonal Symbiodiniaceae cultures. Four of these belonged to Symbiodiniaceae ‘subclade’ Fr3, and three to Clade H, based on nucleotide sequence similarity (ITS2, LSU, cp23S, and mtCOB), representing the first cultures of these taxa. Based on these isolates, we propose two new genera: Freudenthalidium gen. nov. and Halluxium gen. nov., circumscribing Clades Fr3 and H, respectively. Three new species are described: Freudenthalidium heronense, F. endolithicum, and Halluxium pauxillum. Kofoidian tabulations of motile cells confirm previous observations that amphiesmal vesicle arrangements are generally conserved across the family. These descriptions are an important step toward completing the systematic revision of the Symbiodiniaceae. That this contribution was enabled by isolates from an endopsammic habitat highlights the potential of discovering new symbiodiniacean species in the environment, the study of which will lead to a deeper understanding of free-living versus symbiotic life histories in this ecologically important family of dinoflagellates.
Nitschke, MR, Fidalgo, C, Simões, J, Brandão, C, Alves, A, Serôdio, J & Frommlet, JC 2020, 'Symbiolite formation: a powerful in vitro model to untangle the role of bacterial communities in the photosynthesis-induced formation of microbialites', ISME Journal, vol. 14, no. 6, pp. 1533-1546.
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© 2020, The Author(s), under exclusive licence to International Society for Microbial Ecology. Microbially induced calcification is an ancient, community-driven mineralisation process that produces different types of microbialites. Symbiolites are photosynthesis-induced microbialites, formed by calcifying co-cultures of dinoflagellates from the family Symbiodiniaceae and bacteria. Symbiolites encase the calcifying community as endolithic cells, pointing at an autoendolithic niche of symbiotic dinoflagellates, and provide a rare opportunity to study the role of bacteria in bacterial–algal calcification, as symbiodiniacean cultures display either distinct symbiolite-producing (SP) or non-symbiolite-producing (NP) phenotypes. Using Illumina sequencing, we found that the bacterial communities of SP and NP cultures differed significantly in the relative abundance of 23 genera, 14 families, and 2 phyla. SP cultures were rich in biofilm digesters from the phylum Planctomycetes and their predicted metagenomes were enriched in orthologs related to biofilm formation. In contrast, NP cultures were dominated by biofilm digesters from the Bacteroidetes, and were inferred as enriched in proteases and nucleases. Functional assays confirmed the potential of co-cultures and bacterial isolates to produce biofilms and point at acidic polysaccharides as key stimulators for mineral precipitation. Hence, bacteria appear to influence symbiolite formation primarily through their biofilm-producing and modifying activity and we anticipate that symbiolite formation, as a low-complexity in vitro model, will significantly advance our understanding of photosynthesis-induced microbial calcification processes.
Osman, EO, Suggett, DJ, Voolstra, CR, Pettay, DT, Clark, DR, Pogoreutz, C, Sampayo, EM, Warner, ME & Smith, DJ 2020, 'Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities', Microbiome, vol. 8, no. 1.
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© 2020 The Author(s). Background: The capacity of reef-building corals to tolerate (or adapt to) heat stress is a key factor determining their resilience to future climate change. Changes in coral microbiome composition (particularly for microalgal endosymbionts and bacteria) is a potential mechanism that may assist corals to thrive in warm waters. The northern Red Sea experiences extreme temperatures anomalies, yet corals in this area rarely bleach suggesting possible refugia to climate change. However, the coral microbiome composition, and how it relates to the capacity to thrive in warm waters in this region, is entirely unknown. Results: We investigated microbiomes for six coral species (Porites nodifera, Favia favus, Pocillopora damicornis, Seriatopora hystrix, Xenia umbellata, and Sarcophyton trocheliophorum) from five sites in the northern Red Sea spanning 4° of latitude and summer mean temperature ranges from 26.6 °C to 29.3 °C. A total of 19 distinct dinoflagellate endosymbionts were identified as belonging to three genera in the family Symbiodiniaceae (Symbiodinium, Cladocopium, and Durusdinium). Of these, 86% belonged to the genus Cladocopium, with notably five novel types (19%). The endosymbiont community showed a high degree of host-specificity despite the latitudinal gradient. In contrast, the diversity and composition of bacterial communities of the surface mucus layer (SML) - a compartment particularly sensitive to environmental change - varied significantly between sites, however for any given coral was species-specific. Conclusion: The conserved endosymbiotic community suggests high physiological plasticity to support holobiont productivity across the different latitudinal regimes. Further, the presence of five novel algal endosymbionts suggests selection of certain genotypes (or genetic adaptation) within the semi-isolated Red Sea. In contrast, the dynamic composition of bacteria associated with the SML across sites may contribute to holobiont ...
Osman, EO, Suggett, DJ, Voolstra, CR, Pettay, DT, Clark, DR, Pogoreutz, C, Sampayo, EM, Warner, ME & Smith, DJ 2020, 'Correction to: Coral microbiome composition along the northern Red Sea suggests high plasticity of bacterial and specificity of endosymbiotic dinoflagellate communities (Microbiome (2020) 8:8 DOI: 10.1186/s40168-019-0776-5)', Microbiome, vol. 8, no. 1.
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© 2020 The Author(s). Reference. Following publication of the original article [1], the authors reported an error on the legend of of P.damicornis in Fig. 1.
Patil, PP, Vass, I, Kodru, S & Szabó, M 2020, 'A multi-parametric screening platform for photosynthetic trait characterization of microalgae and cyanobacteria under inorganic carbon limitation', PLoS ONE, vol. 15, no. 7 July.
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© 2020 Patil et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Microalgae and cyanobacteria are considered as important model organisms to investigate the biology of photosynthesis; moreover, they are valuable sources of biomolecules for several biotechnological applications. Understanding the species-specific traits of photosynthetic electron transport is extremely important, because it contributes to the regulation of ATP/NADPH ratio, which has direct/indirect links to carbon fixation and other metabolic pathways and thus overall growth and biomass production. In the present work, a cuvettebased setup is developed, in which a combination of measurements of dissolved oxygen, pH, chlorophyll fluorescence and NADPH kinetics can be performed without disturbing the physiological status of the sample. The suitability of the system is demonstrated using a model cyanobacterium Synechocystis sp. PCC6803, as well as biofuel-candidate microalgae species, such as Chlorella sorokiniana, Dunaliella salina and Nannochloropsis limnetica undergoing inorganic carbon (Ci) limitation. Inorganic carbon limitation, induced by photosynthetic Ci uptake under continuous illumination, caused a decrease in the effective quantum yield of PSII (Y(II)) and loss of oxygen-evolving capacity in all species investigated here; these effects were largely recovered by the addition of NaHCO3. Detailed analysis of the dark-light and light-dark transitions of NADPH production/uptake and changes in chlorophyll fluorescence kinetics revealed species- and condition-specific responses. These responses indicate that the impact of decreased Calvin-Benson cycle activity on photosynthetic electron transport pathways involving several sections of the electron transport chain (such as electron transfer via the QA-QB-plas...
Pernice, M, Raina, J-B, Rädecker, N, Cárdenas, A, Pogoreutz, C & Voolstra, CR 2020, 'Down to the bone: the role of overlooked endolithic microbiomes in reef coral health.', The ISME Journal: multidisciplinary journal of microbial ecology, vol. 14, no. 2, pp. 325-334.
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Reef-building corals harbour an astonishing diversity of microorganisms, including endosymbiotic microalgae, bacteria, archaea, and fungi. The metabolic interactions within this symbiotic consortium are fundamental to the ecological success of corals and the unique productivity of coral reef ecosystems. Over the last two decades, scientific efforts have been primarily channelled into dissecting the symbioses occurring in coral tissues. Although easily accessible, this compartment is only 2-3 mm thick, whereas the underlying calcium carbonate skeleton occupies the vast internal volume of corals. Far from being devoid of life, the skeleton harbours a wide array of algae, endolithic fungi, heterotrophic bacteria, and other boring eukaryotes, often forming distinct bands visible to the bare eye. Some of the critical functions of these endolithic microorganisms in coral health, such as nutrient cycling and metabolite transfer, which could enable the survival of corals during thermal stress, have long been demonstrated. In addition, some of these microorganisms can dissolve calcium carbonate, weakening the coral skeleton and therefore may play a major role in reef erosion. Yet, experimental data are wanting due to methodological limitations. Recent technological and conceptual advances now allow us to tease apart the complex physical, ecological, and chemical interactions at the heart of coral endolithic microbial communities. These new capabilities have resulted in an excellent body of research and provide an exciting outlook to further address the functional microbial ecology of the "overlooked" coral skeleton.
Price, S, Kuzhiumparambil, U, Pernice, M & Ralph, PJ 2020, 'Cyanobacterial polyhydroxybutyrate for sustainable bioplastic production: Critical review and perspectives', Journal of Environmental Chemical Engineering, vol. 8, no. 4.
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© 2020 Elsevier Ltd. PHB is a promising bioplastic material that naturally accumulates in many strains of cyanobacteria. This comprehensive review covers recent advances in several topics including PHB metabolism, material properties, relevant extraction methods and protocols, industrial cultivation strategy, current economic assessment and much more. Ultimately, the profitability of cyanobacterial PHB production is controlled by low PHB productivity as well as expensive cultivation and harvesting equipment. Several research areas for improving viability of cyanobacterial PHB production have also been summarised and perspectives on future efforts suggested including; screening, genetic modification, wastewater cultivation and using chemical modulators among others.
Raven, JA, Suggett, DJ & Giordano, M 2020, 'Inorganic carbon concentrating mechanisms in free-living and symbiotic dinoflagellates and chromerids', Journal of Phycology.
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© 2020 Phycological Society of America Photosynthetic dinoflagellates are ecologically and biogeochemically important in marine and freshwater environments. However, surprisingly little is known of how this group acquires inorganic carbon or how these diverse processes evolved. Consequently, how CO2 availability ultimately influences the success of dinoflagellates over space and time remains poorly resolved compared to other microalgal groups. Here we review the evidence. Photosynthetic core dinoflagellates have a Form II RuBisCO (replaced by Form IB or Form ID in derived dinoflagellates). The in vitro kinetics of the Form II RuBisCO from dinoflagellates are largely unknown, but dinoflagellates with Form II (and other) RuBisCOs have inorganic carbon concentrating mechanisms (CCMs), as indicated by in vivo internal inorganic C accumulation and affinity for external inorganic C. However, the location of the membrane(s) at which the essential active transport component(s) of the CCM occur(s) is (are) unresolved; isolation and characterization of functionally competent chloroplasts would help in this respect. Endosymbiotic Symbiodiniaceae (in Foraminifera, Acantharia, Radiolaria, Ciliata, Porifera, Acoela, Cnidaria, and Mollusca) obtain inorganic C by transport from seawater through host tissue. In corals this transport apparently provides an inorganic C concentration around the photobiont that obviates the need for photobiont CCM. This is not the case for tridacnid bivalves, medusae, or, possibly, Foraminifera. Overcoming these long-standing knowledge gaps relies on technical advances (e.g., the in vitro kinetics of Form II RuBisCO) that can functionally track the fate of inorganic C forms.
Rinke, C, Rubino, F, Messer, LF, Youssef, N, Parks, DH, Chuvochina, M, Brown, M, Jeffries, T, Tyson, GW, Seymour, JR & Hugenholtz, P 2020, 'Correction: A phylogenomic and ecological analysis of the globally abundant Marine Group II archaea (Ca. Poseidoniales ord. nov.).', The ISME journal.
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An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Ros, M, Camp, EF, Hughes, DJ, Crosswell, JR, Warner, ME, Leggat, WP & Suggett, DJ 2020, 'Unlocking the black-box of inorganic carbon-uptake and utilization strategies among coral endosymbionts (Symbiodiniaceae)', Limnology and Oceanography, vol. 65, no. 8, pp. 1747-1763.
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© 2020 Association for the Sciences of Limnology and Oceanography Dinoflagellates within the family Symbiodiniaceae are widespread and fuel metabolism of reef-forming corals through photosynthesis. Adaptation in capacity to harvest and utilize light, and “safely” process photosynthetically generated energy is a key factor regulating their broad ecological success. However, whether such adaptive capacity similarly extends to how Symbiodiniaceae species and genotypes assimilate inorganic carbon (Ci) remains unexplored. We build on recent approaches exploring functional diversity of fitness traits to identify whether Ci uptake and incorporation could be reconciled with evolutionary adaptation among Symbiodiniaceae. We examined phylogenetically diverse Symbiodiniaceae cultures (23 isolates, 6 genera) to track how carbon was invested into cellular uptake, excretion, and growth (cell size, division, storage). Gross carbon uptake rates (GPC) over 1 h varied among isolates grown at 26°C (0.63–3.08 pg C [cell h]−1) with no evident pattern with algal phylogeny. Intriguingly, net carbon uptake rates (24 h) were often higher (1.01–5.54 pg C [cell h]−1) than corresponding values of GPC—we discuss how such GPC measurements may reflect highly conserved biological characteristics for cultured cells linked to high metabolic dependency on photorespiration and heterotrophy. Three isolates from different genera (Cladocopium goreaui, Durusdinium trenchii, and Effrenium voratum) were additionally grown at 20°C and 30°C. Here, Ci uptake consistently decreased with temperature-driven declines in growth rate, suggesting environmental regulation outweighs phylogenetic organization of carbon assimilation capacity among Symbiodiniaceae. Together, these data demonstrate environmental regulation and ecological success among Symbiodiniaceae likely rests on plasticity of upstream photosynthetic processes (light harvesting, energy quenching, etc.) to overcome evolutionary-conserved limitations i...
Siboni, N, Abrego, D, Puill-Stephan, E, King, WL, Bourne, DG, Raina, J-B, Seymour, JR & Harder, T 2020, 'Crustose coralline algae that promote coral larval settlement harbor distinct surface bacterial communities', CORAL REEFS.
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Soja-Woźniak, M, Laiolo, L, Baird, ME, Matear, R, Clementson, L, Schroeder, T, Doblin, MA & Suthers, IM 2020, 'Effect of phytoplankton community size structure on remote-sensing reflectance and chlorophyll a products', Journal of Marine Systems, vol. 211.
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© 2020 Elsevier B.V. Remotely-sensed ocean colour is the main tool for estimating chlorophyll a (Chl-a) concentration and primary productivity on the global scale. In order to investigate the source of errors in remotely-sensed Chl-a concentration we obtained in situ bio-optical properties, in situ reflectances, satellite-derived reflectances and the Chl-a concentration satellite products of the Ocean and Land Colour Instrument (OLCI) Instrument on board Sentinel-3 A in waters off eastern Australia. The mesoscale eddies of these oligotrophic waters provide contrasting phytoplankton communities that allowed us to focus on the effect of phytoplankton size as a source of errors. In these waters, cold-core cyclonic eddies (CE) are dominated by large phytoplankton cells, while small cells dominate warm-core anticyclonic eddies (ACE). The chlorophyll-specific absorption and backscattering from contrasting sites show significant difference due to the differing package effect of phytoplankton size distributions. After normalising the absorption and backscattering spectra to Chl-a associated with just small phytoplankton, the spectra of optical properties become much more similar, showing that small-sized phytoplankton dominate IOPs even when large cells contain the greater fraction of Chl-a concentration of the phytoplankton community. Measured in situ reflectances agreed with reflectances calculated using a simple optical model based on measured IOPs. Furthermore, the in situ measured reflectances agreed well with the OLCI reflectance (mean normalised bias (MNB) of 7% for wavelengths <600 nm). However, a systematic underestimation of Chl-a concentrations by the OLCI algorithms was found in the region of cyclonic eddies characterised by increased Chl-a concentration and dominance of large-sized phytoplankton. A similar underprediction was found in Chl-a concentration calculated with the band-ratio OC4Me algorithm using in situ and IOP-calculated reflectance. Excluding Ch...
Suggett, DJ & Smith, DJ 2020, 'Coral bleaching patterns are the outcome of complex biological and environmental networking.', Global Change Biology, vol. 26, no. 1, pp. 68-79.
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Continued declines in coral reef health over the past three decades have been punctuated by severe mass coral bleaching-induced mortality events that have grown in intensity and frequency under climate change. Intensive global research efforts have therefore persistently focused on bleaching phenomena to understand where corals bleach, when and why-resulting in a large-yet still somewhat patchy-knowledge base. Particularly catastrophic bleaching-induced coral mortality events in the past 5 years have catalyzed calls for a more diverse set of reef management tools, extending far beyond climate mitigation and reef protection, to also include more aggressive interventions. However, the effectiveness of these various tools now rests on rapidly assimilating our knowledge base of coral bleaching into more integrated frameworks. Here, we consider how the past three decades of intensive coral bleaching research has established the basis for complex biological and environmental networks, which together regulate outcomes of bleaching severity. We discuss how we now have enough scaffold for conceptual biological and environmental frameworks underpinning bleaching susceptibility, but that new tools are urgently required to translate this to an operational system informing-and testing-bleaching outcomes. Specifically, adopting network models that can fully describe and predict metabolic functioning of coral holobionts, and how this functioning is regulated by complex doses and interactions among environmental factors. Identifying knowledge gaps limiting operation of such models is the logical step to immediately guide and prioritize future experiments and observations. We are at a time-critical point where we can implement new capacity to resolve how coral bleaching patterns emerge from complex biological-environmental networks, and so more effectively inform rapidly evolving ecological management and social adaptation frameworks aimed at securing the future of coral reefs.
Suggett, DJ, Edmondson, J, Howlett, L & Camp, EF 2020, 'Coralclip®: a low‐cost solution for rapid and targeted out‐planting of coral at scale', Restoration Ecology.
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Re‐attaching or out‐planting coral as fragments, colonies, and on larval settlement devices to substrates is a major bottleneck limiting scalabilty and viability of reef restoration practices. Many attachment approaches are in use, but none that are low‐cost, opportunistic, rapid but effective, for integration into existing tour operations on the Great Barrier Reef (GBR) where staff and boat time is a major cost and chemical fixatives cannot be easily used. We describe a novel attachment device—Coralclip®—developed to meet this need and so aid maintenance and restoration of GBR tourism sites. Coralclip® is a stainless steel springclip attached by a nail integrated through the spring coil, and can be deployed with a coral fragment in as fast as 15 seconds. Initial laboratory tests demonstrated that Coralclip® secured coral fragments or larval settlement tiles under dynamic flow regimes characteristic of exposed reefs. Coral out‐planting from fragments of opportunity and from nurseries (n = 4,580; 0.3–1.9 coral/minute; US$0.6–3.0/coral deployed) or larval settlement tiles (n = 400; 2.5 tiles/minute; US$0.5 tile deployed−1) when deployed by divers from routine boat operations at Opal Reef confirmed highly effective attachment, with ≤15% failure of clips found after 3–7 months. We discuss how Coralclip® is a cost‐effective means to support reef maintenance and restoration practices.
Sukacova, K, Buzova, D & Cerveny, J 2020, 'Biphasic optimization approach for maximization of lipid production by the microalga Chlorella pyrenoidosa', FOLIA MICROBIOLOGICA, vol. 65, no. 5, pp. 901-908.
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Sutherland, DL & Ralph, PJ 2020, '15 years of research on wastewater treatment high rate algal ponds in New Zealand: discoveries and future directions', New Zealand Journal of Botany.
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© 2020, © 2020 The Royal Society of New Zealand. Over the last 15 years, New Zealand led research on wastewater treatment high rate algal ponds (HRAP) has focused on ways to optimise pond performance, particularly with respect to nutrient removal and resource recovery (microalgal biomass production). The primary motivation for most of this research has been the need to cost-effectively improve wastewater treatment, particularly in small towns and rural communities, where wastewater treatment would otherwise be unaffordable. The ability to recover resources (water and nutrients) helps enable a circular bio-economy, through the reuse of these recovered resources in future products. New Zealand HRAP research has focused on 10 broad categories, including improving pond performance (nutrient removal and biomass yield), environmental impacts of HRAPs, pond design and operation, microalgal and zooplankton community composition and control, algal-based products, enhancing phosphorus removal, biomass harvesting and emerging contaminants. Research has been carried out at a range of scales, including mesocosm, pilot-scale and full-scale. Simple modification to how HRAPs are operated, such as culture depth, operating ponds in series, biomass recycling and night-time CO2 addition, have been shown to improve pond performance, particularly nutrient removal, biomass productivity, species dominance maintenance or zooplankton graze control. However, despite our improved understandings over the last 15 years, there are still a number of priorities for increasing HRAP performance, including effective CO2 addition at full-scale, improving phosphorus removal and reducing potential environmental impacts of HRAPs. Uptake of HRAP technology by local government bodies and industries is low and the reasons for this are not fully clear. Cost-effective and sustainable harvesting of the microalgal/bacterial biomass, to ensure effluent discharge meets total nutrient and total suspended solids ...
Sutherland, DL, Burke, J & Ralph, PJ 2020, 'Flow-way water depth affects algal productivity and nutrient uptake in a filamentous algae nutrient scrubber', JOURNAL OF APPLIED PHYCOLOGY.
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Sutherland, DL, Burke, J & Ralph, PJ 2020, 'Increased harvest frequency improves biomass yields and nutrient removal on a filamentous algae nutrient scrubber', ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, vol. 51.
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Sutherland, DL, Burke, J, Leal, E & Ralph, PJ 2020, 'Effects of nutrient load on microalgal productivity and community composition grown in anaerobically digested food-waste centrate', ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, vol. 51.
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Sutherland, DL, Howard-Williams, C, Ralph, P & Hawes, I 2020, 'Environmental drivers that influence microalgal species in meltwater pools on the McMurdo Ice Shelf, Antarctica', Polar Biology, vol. 43, no. 5, pp. 467-482.
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© 2020, Springer-Verlag GmbH Germany, part of Springer Nature. Rich in both microbial mat biomass and species diversity, the meltwater ponds of the McMurdo Ice Shelf (MIS) form important biodiversity and productivity elements in an otherwise barren landscape. These ponds are thought to be sensitive indicators of climate change-driven fluxes in pond water balance but our ability to predict such effects is confounded by our poor understanding of the inherent variability of these communities in response to the physico-chemical environment. Understanding how microbial communities are shaped across broad physico-chemical gradients may allow better predictions of the effects of climate change on the MIS wetlands. Our study found that distinct clustering of community types against environmental variables was apparent for both the diatom and cyanobacterial communities. For diatoms, conductivity was correlated with the separation of five significantly distinct communities. Significant differences in NH4–N concentrations were correlated to the three distinct cyanobacterial communities but many of the cyanobacteria morphotypes were recorded across a wide ecological range. More distinct community types suggested that diatoms were more sensitive to environmental change in these ponds than the cyanobacteria, despite the latter’s overall dominance. Distinct community clusters for diatoms, and to a lesser extent cyanobacteria, suggest that changes at a functional group level may be more important than at the level of individual species. Further understanding of diatom functional groups would provide us with the opportunity to hindcast past climates and water budgets within the Antarctic region. However, the disconnect between biomass and community composition currently prevents hindcasting past productivities in relation to environmental changes.
Sutherland, DL, Park, J, Heubeck, S, Ralph, PJ & Craggs, RJ 2020, 'Size matters – Microalgae production and nutrient removal in wastewater treatment high rate algal ponds of three different sizes', Algal Research, vol. 45.
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© 2019 Elsevier B.V. High rate algal ponds for coupled wastewater treatment and resource recovery have been the focus of much international research over the last 15 years. Microalgal biomass productivity reported in full-scale studies (1-ha or greater) have often been substantially lower than that reported from smaller scale ponds in similar climates, regardless of the season or the dominant microalgal species used. The disconnect between smaller-scale and full-scale productivity is unclear and uncertainty remains regarding the applicability of smaller scale studies to full-scale systems. In order to better understand the differences in reported productivity, the performance of three different size wastewater treatment high rate algal ponds (5 m2, 330 m2 and 1-ha) were assessed with respect to nutrient removal and microalgal productivity over three seasons. Both daily areal nutrient removal and biomass production were affected by the size of the pond. NH4-N removal via nitrification/denitrification decreased with increasing pond size, with the highest removal rate in the 5 m2 pond and the lowest in the 1-ha. Microalgal areal productivity was maximal in the 330 m2 pond, suggesting that a combination of mixing frequency and higher photosynthetic potential under low light conditions were the main drivers of enhanced productivity in this pond compared to the 5 m2 (mesocosm) and 1-ha (full-scale) ponds. The lowest daily nutrient removal and biomass production occurred in the 1-ha (full-scale) pond. Our results suggest that, based on the current design and operation of high rate algal ponds, the optimum size for maximum productivity is considerably smaller than the current full-scale systems. This has implications for commercial scale systems, with respect to capital and operational costs.
Sutherland, DL, Park, J, Ralph, PJ & Craggs, RJ 2020, 'Improved microalgal productivity and nutrient removal through operating wastewater high rate algal ponds in series', ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS, vol. 47.
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Teoh, F, Shah, B, Ostrowski, M & Paulsen, I 2020, 'Comparative membrane proteomics reveal contrasting adaptation strategies for coastal and oceanic marine Synechococcus cyanobacteria', ENVIRONMENTAL MICROBIOLOGY, vol. 22, no. 5, pp. 1816-1828.
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Thackeray, SJ, Robinson, SA, Smith, P, Bruno, R, Kirschbaum, MUF, Bernacchi, C, Byrne, M, Cheung, W, Cotrufo, MF, Gienapp, P, Hartley, S, Janssens, I, Jones, TH, Kobayashi, K, Luo, Y, Penuelas, J, Sage, R, Suggett, DJ, Way, D & Long, S 2020, 'Civil disobedience movements such as School Strike for the Climate are raising public awareness of the climate change emergency', GLOBAL CHANGE BIOLOGY, vol. 26, no. 3, pp. 1042-1044.
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Thomson, ACG, Kristensen, E, Valdemarsen, T & Quintana, CO 2020, 'Short-term fate of seagrass and macroalgal detritus in Arenicola marina bioturbated sediments', Marine Ecology Progress Series, vol. 639, pp. 21-35.
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© The authors 2020. Seagrass meadows are globally important ecosystems for carbon (C) sequestration. However, bioturbation by benthic fauna can alter the distribution, degradation and overall preservation of C in the sediment. We performed a 4 wk laboratory experiment to investigate the short-term degradation and burial of 2 major C sources in bare sediments associated with seagrass ecosystems. Eelgrass Zostera marina and macroalgal (Fucus vesiculosus) detritus were amended in sediment with and without bioturbation by the common polychaete Arenicola marina. Bioturbation did not significantly affect the loss of eelgrass detritus (>0.5 mm), but caused a rapid burial of this material as a discrete layer (55% recovery) at sediment depths ranging from 8 to 14 cm. A. marina effects on macroalgal detritus were more pronounced, resulting, in total, in an 80% loss of macroalgal detritus by microbial degradation and worm ingestion. We conclude that A. marina bioturbation effectively buries eelgrass detritus into deep anoxic sediments, but we cannot confirm that this leads to enhanced C preservation in coastal ecosystems. In contrast, A. marina bioturbation significantly increases the degradation of macroalgal tissue, and it is unlikely that this detritus is a major source for permanent C burial.
Tran, N-AT, Tamburic, B, Evenhuis, CR & Seymour, JR 2020, 'Bacteria-mediated aggregation of the marine phytoplanktonThalassiosira weissflogiiandNannochloropsis oceanica', JOURNAL OF APPLIED PHYCOLOGY, vol. 32, no. 6, pp. 3735-3748.
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Trevathan-Tackett, SM, Jeffries, TC, Macreadie, PI, Manojlovic, B & Ralph, P 2020, 'Long-term decomposition captures key steps in microbial breakdown of seagrass litter', SCIENCE OF THE TOTAL ENVIRONMENT, vol. 705.
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Verma, A, Hughes, DJ, Harwood, DT, Suggett, DJ, Ralph, PJ & Murray, SA 2020, 'Functional significance of phylogeographic structure in a toxic benthic marine microbial eukaryote over a latitudinal gradient along the East Australian Current', Ecology and Evolution, vol. 10, pp. 6257-6273.
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Viet, KN, King, WL, Siboni, N, Mahbub, KR, Dove, M, O'Connor, W, Seymour, JR & Labbate, M 2020, 'The Sydney rock oyster microbiota is influenced by location, season and genetics', AQUACULTURE, vol. 527.
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Wilkinson, S, Ralph, P & Biloria, N 2020, 'The technical Issues associated with Algae Building Technology', International Journal of Building Pathology and Adaptation.
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As the impacts of climate change become more evident, the need to adopt new ways of constructing buildings becomes more urgent. The earth has experienced hotter climates globally for the last 70 years (NASA 2019) and this has resulted in unprecedented levels of bushfire in Australia, flooding in the UK and drought in Africa in early 2020 (World Resources Institute, 2019). The predictions are for increased temperatures (Climate Chip, 2020) globally and increasing carbon emissions from fossil fuel consumption. There is a critical need to reduce the reliance on fossil fuels as a building energy source (WCED 1987). Existing renewables focus on solar, wind and wave power, where technological improvements have increased efficiencies (Hinnells, 2008). Uptake of the technologies is variable depending on location and willingness to adopt renewables. As well as further uptake of existing renewable energy sources, we need to look wider and across traditional discipline groups, at new technologies such as bio-technologies. One potential energy source is biofuels. Biofuels are produced from biomass, which is algae. In 2016 the BIQ, a four storey apartment building, was constructed in Hamburg, Germany. The BIQ features glazed façade panels filled with algae to produce biomass and solar thermal energy. Could algae building technology (ABT), in the form of façade panels offer a new renewable energy source?
What are the technical issues associated with Algae building technology? This qualitative research sought to identify what technical issues likely to arise in terms of algae building construction, operation and maintenance. Semi structured interviews with 24 experienced built environ-ment professionals in Australia were undertaken in 2016 to assess the most likely issues that could arise with this new innovative technology.
As a result, a greater understanding of the range of technical issues related to design, construction, maintenance and operation were identified, as well ...
Yan, J, Kuzhiumparambil, U, Bandodkar, A, Bandodkar, S, Dale, RC & Fu, S 2020, 'Cerebrospinal fluid metabolites in tryptophan-kynurenine and nitric oxide pathways: biomarkers for acute neuroinflammation', DEVELOPMENTAL MEDICINE AND CHILD NEUROLOGY.
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