References of "Wilmotte, Annick"
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See detailCyanobacteria inhabiting biological soil crusts of a polar desert: Sør Rondane Mountains, Antarctica
Pushkareva, Ekaterina; Pessi, Igor S; Namsaraev, Zorigto et al

in Systematic and Applied Microbiology (in press)

Molecular and morphological methods were applied to study cyanobacterial community composition in biological soil crusts (BSCs) from four areas (two nunataks and two ridges) in the Sør Rondane Mountains ... [more ▼]

Molecular and morphological methods were applied to study cyanobacterial community composition in biological soil crusts (BSCs) from four areas (two nunataks and two ridges) in the Sør Rondane Mountains, Antarctica. The sampling sites serve as control areas for open top chambers (OTCs) which were placed in 2010 at the time of sample collection and will be compared with BSC samples taken from the OTCs in future. Cyanobacterial cell biovolume was estimated using epifluorescence microscopy, which revealed the dominance of filamentous cyanobacteria in all studied sites except the Utsteinen ridge, where unicellular cyanobacteria were the most abundant. Cyanobacterial diversity was studied by a combination of molecular fingerprinting methods based on the 16S rRNA gene (denaturing gradient gel electrophoresis (DGGE) and 454 pyrosequencing) using cyanobacteria specific primers. The number of DGGE sequences obtained per site was variable and, therefore, a high-throughput method was later employed to improve the diversity coverage. Consistent with previous surveys in Antarctica, both methods showed that filamentous cyanobacteria such as Leptolyngbya sp., Phormidium sp. and Microcoleus sp. were dominant in the studied sites. In addition, the studied localities differed in substrate type, climatic conditions and soil parameters, which likely resulted in differences in cyanobacterial community composition. Furthermore, the BSC growing on gneiss pebbles had lower cyanobacterial abundances than BSCs associated to granitic substrates. [less ▲]

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See detailEducation and Outreach by the Antarctic Treaty Parties, Observers and Experts under the framework of the Antarctic Treaty Consultative meetings
Xavier, José C; Mateev, Dragomir; Capper, linda et al

in Polar Record (in press)

The development of formal discourse about education and outreach within the Antarctic Treaty Consultative Meetings (ATCM), and the influence of major international activities in this field, are described ... [more ▼]

The development of formal discourse about education and outreach within the Antarctic Treaty Consultative Meetings (ATCM), and the influence of major international activities in this field, are described. We reflect on the ATCM Parties’ approach to implementing the ambition of the Protocol on Environmental Protection to the Antarctic Treaty Article 6.1.a, to promote the educational value of Antarctica and its environment, and we examine the role of workshops and expert groups within the Scientific Committee on Antarctic Research (SCAR), the International Union for the Conservation of Nature (IUCN), and the Council of Managers of National Antarctic Programmes, that emerged in the 1990s, in stimulating discussion within the ATCM. These early initiatives were a prelude to the development and implementation of a large number of International Polar Year (IPY) education and outreach programmes. The establishment of an Antarctic Treaty System Intersessional Contact Group, and an on-line forum on education and outreach during the 2015 ATCM in Bulgaria, is a legacy of IPY and is the next step in fostering collaboration to engage people around the world in the importance and relevance of Antarctica to our daily lives. [less ▲]

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See detailAntarctic environmental protection: strengthening the links between science and governance
Hughes, Kevin; Constable, Andrew; Frenot, Yves et al

in Environmental Science and Policy (2018), 83

The Antarctic has significant environmental, scientific, historic, and intrinsic values, all of which are worth protecting into the future. Nevertheless, the area is subject to an increasing level and ... [more ▼]

The Antarctic has significant environmental, scientific, historic, and intrinsic values, all of which are worth protecting into the future. Nevertheless, the area is subject to an increasing level and diversity of human activities that may impact these values within marine, terrestrial and cryosphere environments. Threats to the Antarctic environment, and to the aforementioned values, include climate change, pollution, habitat destruction, wildlife disturbance and non-native species introductions. Over time, a suite of legally binding international agreements, which form part of the Antarctic Treaty System (ATS), has been established to help safeguard the Antarctic environment and provide a framework for addressing the challenges arising from these threats. Foremost among these agreements are the Protocol on Environmental Protection to the Antarctic Treaty and the Convention on the Conservation of Antarctic Marine Living Resources. Many scientists working in Antarctica undertake research that is relevant to Antarctic environmental policy development. More effective two-way interaction between scientists and those responsible for policy development would further strengthen the governance framework, including by (a) better communication of policy makers’ priorities and identification of related science requirements and (b) better provision by scientists of ‘policy-ready’ information on existing priorities, emerging issues and scientific/technological advances relevant to environmental protection. The Scientific Committee on Antarctic Research (SCAR) has a long and successful record of summarizing policy-relevant scientific knowledge to policy makers, such as through its Group of Specialists on Environmental Affairs and Conservation (GOSEAC) up to 2002, currently the SCAR Standing Committee on the Antarctic Treaty System (SCATS) and recently through its involvement in the Antarctic Environments Portal. Improvements to science-policy communication mechanisms, combined with purposeful consideration of funding opportunities for policy-relevant science, would greatly enhance international policy development and protection of the Antarctic environment. [less ▲]

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See detailThe survival toolkit of the Antarctic cyanobacterium Phormidesmis priestleyi ULC007
Lara, Yannick ULiege; Durieu, Benoit ULiege; Pessi, Igor et al

Conference (2018, March)

Extreme seasonality led by rapid changes in day length and harsh environmental conditions make Antarctica a unique habitat. Freshwater ecosystems range from cryoecosystems and ice shelf meltwater ponds to ... [more ▼]

Extreme seasonality led by rapid changes in day length and harsh environmental conditions make Antarctica a unique habitat. Freshwater ecosystems range from cryoecosystems and ice shelf meltwater ponds to perennially ice-covered lakes where conspicuous benthic microbial mat communities constitute most of the biomass. In these mats, cyanobacteria form the matrix in which other microorganisms can live, and where they are the key primary producers and main drivers of the carbon and food webs[1].
Narrow filamentous cyanobacteria belonging to the order Pseudanabaenales are especially abundant in polar microbial mats [2]. Despite the dominance of cyanobacteria on the Antarctic continent, there is currently no study available on the genomic evolution of Antarctic cyanobacteria. Here we investigate the genome of a widely distributed Antarctic cyanobacterium, Phormidium priestleyi ULC007. To provide a better understanding of the survival strategies of this taxon, we used high-throughput sequencing technologies to investigate its geographic distribution and genome evolution. More precisely, we investigated the abundance of genes in targeted functional categories based on the RAST subsystems technology, so as to provide a better overview of the genetic mechanisms involved in cold adaptation and circadian oscillation [3]. In Polar regions, low temperatures lead to the success of particular organisms featuring adaptations to molecular and cellular disturbances such as rigidity of membranes, reduction of enzyme-catalyzed reactions, and solute transport. Our main results underline the importance of functional categories of genes involved in the production of key molecules for the survival of polar P. priestleyi (e.g. exopolysaccharides, chaperone proteins, fatty acids and phospholipids). [less ▲]

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See detailToxic Cyanobacteria in Svalbard: Chemical Diversity of Microcystins Detected Using a Liquid Chromatography Mass Spectrometry Precursor Ion Screening Method
Kleinteich, Julia; Puddick, Jonathan; Wood, Susanna A et al

in Toxins (2018), 10(147), 1-15

Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs) with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of ... [more ▼]

Cyanobacteria synthesize a large variety of secondary metabolites including toxins. Microcystins (MCs) with hepato- and neurotoxic potential are well studied in bloom-forming planktonic species of temperate and tropical regions. Cyanobacterial biofilms thriving in the Polar Regions have recently emerged as a rich source for cyanobacterial secondary metabolites including previously undescribed congeners of microcystin. However, detection and detailed identification of these compounds is difficult due to unusual sample matrices and structural congeners produced. We here report a time-efficient liquid chromatography-mass spectrometry (LC-MS) precursor ion screening method that facilitates microcystin detection and identification. We applied this method to detect six different MC congeners in 8 out of 26 microbial mat samples of the Svalbard Archipelago in the Arctic. The congeners, of which [Asp3, ADMAdda5, Dhb7] MC-LR was most abundant, were similar to those reported in other polar habitats. Microcystins were also determined using an Adda-specific enzyme-linked immunosorbent assay (Adda-ELISA). Nostoc sp. was identified as a putative toxin producer using molecular methods that targeted 16S rRNA genes and genes involved in microcystin production. The mcy genes detected showed highest similarities to other Arctic or Antarctic sequences. The LC-MS precursor ion screening method could be useful for microcystin detection in unusual matrices such as benthic biofilms or lichen [less ▲]

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See detailCommunity structure and distribution of benthic cyanobacteria in Antarctic lacustrine microbial mats
Pessi, Igor S.; Lara, Yannick ULiege; Durieu, Benoit ULiege et al

in FEMS Microbiology Ecology (2018), 94(5), 042

The terrestrial Antarctic Realm has recently been divided into 16 Antarctic Conservation Biogeographic Regions (ACBRs) based on environmental properties and the distribution of biota. Despite their ... [more ▼]

The terrestrial Antarctic Realm has recently been divided into 16 Antarctic Conservation Biogeographic Regions (ACBRs) based on environmental properties and the distribution of biota. Despite their prominent role in the primary production and nutrient cycling in Antarctic lakes, cyanobacteria were only poorly represented in the biological dataset used to delineate these ACBRs. Here we provide a first high-throughput sequencing (HTS) insight into the spatial distribution of benthic cyanobacterial communities in Antarctic lakes located in four distinct, geographically distant ACBRs and covering a range of limnological conditions. Cyanobacterial community structure differed between saline and freshwater lakes. No clear bioregionalisation was observed, as clusters of community similarity encompassed lakes from distinct ACBRs. Most phylotypes (77.0%) were related to cyanobacterial lineages (defined at ≥ 99.0% 16S rRNA gene sequence similarity) restricted to the cold biosphere, including lineages potentially endemic to Antarctica (55.4%). The latter were generally rare and restricted to a small number of lakes, while more ubiquitous phylotypes were generally abundant and present in different ACBRs. These results point to a widespread distribution of some cosmopolitan cyanobacterial phylotypes across the different Antarctic ice-free regions, but also suggest the existence of dispersal barriers both within and between Antarctica and the other continents. [less ▲]

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See detailEdible cyanobacterial genus Arthrospira: actual state of the art in cultivation methods, genetics and application in medicine
Furmaniak, Magda; Misztak, Agnieszka; Franczuk, Martyna et al

in Frontiers in Microbiology (2017)

The cyanobacterial genus Arthrospira appears very conserved and has been divided into five main genetic clusters on the basis of molecular taxonomy markers. Genetic studies of seven Arthrospira strains ... [more ▼]

The cyanobacterial genus Arthrospira appears very conserved and has been divided into five main genetic clusters on the basis of molecular taxonomy markers. Genetic studies of seven Arthrospira strains, including genome sequencing, have enabled a better understanding of those photosynthetic prokaryotes. Even though genetic manipulations have not yet been performed with success, many genomic and proteomic features such as stress adaptation, nitrogen fixation, or biofuel production have been characterized. Many of above-mentioned studies aimed to optimize the cultivation conditions. Factors like the light intensity and quality, the nitrogen source, or different modes of growth (auto-, hetero-, or mixotrophic) have been studied in detail. The scaling-up of the biomass production using photobioreactors, either closed or open, was also investigated to increase the production of useful compounds. The richness of nutrients contained in the genus Arthrospira can be used for promising applications in the biomedical domain. Ingredients such as the calcium spirulan, immulina, C-phycocyanin, and γ-linolenic acid (GLA) show a strong biological activity. Recently, its use in the fight against cancer cells was documented in many publications. The health-promoting action of “Spirulina” has been demonstrated in the case of cardiovascular diseases and age-related conditions. Some compounds also have potent immunomodulatory properties, promoting the growth of beneficial gut microflora, acting as antimicrobial and antiviral. Products derived from Arthrospira were shown to successfully replace biomaterial scaffolds in regenerative medicine. Supplementation with the cyanobacterium also improves the health of livestock and quality of the products of animal origin. They were also used in cosmetic preparations. [less ▲]

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See detailAvoidance of protein oxidation correlates with the desiccation and radiation resistance of hot and cold desert strains of the cyanobacterium Chroococcidiopsis
Fagliarone, Claudia; Mosca, Claudia; Ubaldi, Ilaria et al

in Extremophiles : Life Under Extreme Conditions (2017), 21

In order to investigate the relationship between desiccation and the extent of protein oxidation in desert strains of Chroococcidiopsis a selection of 10 isolates from hot and cold deserts and the ... [more ▼]

In order to investigate the relationship between desiccation and the extent of protein oxidation in desert strains of Chroococcidiopsis a selection of 10 isolates from hot and cold deserts and the terrestrial cyanobacterium Chroococcidiopsis thermalis sp. PCC 7203, were exposed to desiccation (air-drying) and analysed for survival. Strain CCMEE 029 from the Negev desert and the aquatic cyanobacterium Synechocystis sp. PCC 6803 were further investigated for protein oxidation after desiccation (drying over silica gel), treatment with H2O2 up to 1M and exposure to γ-rays up to 25 kGy. Then a selection of desert strains of Chroococcidiopsis with different survival rates after prolonged desiccation, as well as Synechocystis sp. PCC 6803 and Chroococcidiopsis thermalis sp. PCC 7203, were analysed for protein oxidation after treatment with 10 mM and 100 mM of H2O2. Results suggest that in the investigated strains a tight correlation occurs between desiccation and radiation tolerance and avoidance of protein oxidation [less ▲]

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See detailBioinformatic Processing of Amplicon Sequencing Datasets
Sweetlove, Maxime; Obbels, Dagmar; Verleyen, Elie et al

in Kurmayer, Rainer; Sivonen, Kaarina; Wilmotte, Annick (Eds.) et al Molecular Tools for the Detection and Quantification of Toxigenic Cyanobacteria (2017)

Amplicon sequencing can be a very powerful approach for detecting toxic cyanobacteria or any other kind of microorganism during monitoring programs. However, owing to the huge size of next-generation ... [more ▼]

Amplicon sequencing can be a very powerful approach for detecting toxic cyanobacteria or any other kind of microorganism during monitoring programs. However, owing to the huge size of next-generation sequencing (NGS) datasets (up to several Gb), there is an obvious need for semi-automatic data processing and statistical analysis, as well as visualization of the patterns found. Importantly, raw NGS data contain errors, some of which are easily detected (e.g. too short or low-quality reads), while others remain hidden even after the most stringent quality controls (e.g. chimeras, contaminations, reads with large insertions or deletions, referred to as “indels”). As a consequence, NGS data need to be interpreted with caution, and bioinformatics analysis implementing poor error identification can easily lead to erroneous conclusions. Hence, a crucial step in the analysis of NGS data is the detection and removal of as many erroneous reads as possible. Moreover, bioinformatics involve additional preprocessing steps, including demultiplexing (i.e. grouping reads to samples according to the barcode sequence), deleting non-biological tags together with the adaptors and primer sequences, and removing chimeric sequences. In addition, the bioinformatics pipelines enable the quality-filtered sequences to be clustered into biologically relevant operational taxonomic units (OTUs), which form the basis of the statistical analysis, including the calculation of alpha- and beta-diversity. [less ▲]

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See detailDNA (Diagnostic) and cDNA Microarray
Rantala-Yilinen, Anne; Sivonen, Kaarina; Wilmotte, Annick ULiege

in Kurmayer, Rainer; Sivonen, Kaarina; Wilmotte, Annick (Eds.) et al Molecular Tools for the Detection and Quantification of Toxigenic Cyanobacteria (2017)

Diagnostic microarrays have been used to study cyanobacterial diversity in environmental samples. They usually include sequences (probes) for only one or a few genes allowing a number of genera/species to ... [more ▼]

Diagnostic microarrays have been used to study cyanobacterial diversity in environmental samples. They usually include sequences (probes) for only one or a few genes allowing a number of genera/species to be detected. In contrast, cDNA microarrays are used for screening genome-wide changes in gene expression and include probes for all or most genes in one strain . The purpose of this sub-chapter is to introduce the principle of a diagnostic microarray (= DNA chip) that uses a ligation detection reaction (LDR) and universal microarray to simultaneously detect and identify all potential microcystin and nodularin producers present in a sample. This is especially useful when monitoring environmental samples that can contain many cyanobacterial genera, including toxin-producing strains. [less ▲]

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See detailIsolation, Purification, and Cultivation of Toxigenic Cyanobacteria
Haande, Sigrid; Jasser, Iwona; Gugger, Muriel et al

in Kurmayer, Rainer; Sivonen, Kaarina; Wilmotte, Annick (Eds.) et al Molecular Tools for the Detection and Quantification of Toxigenic Cyanobacteria (2017)

This chapter summarizes the most commonly used methods for the isolation, purification, and cultivation of toxic cyanobacteria. The aim is to give general advice on how to isolate and maintain clonal ... [more ▼]

This chapter summarizes the most commonly used methods for the isolation, purification, and cultivation of toxic cyanobacteria. The aim is to give general advice on how to isolate and maintain clonal cyanobacterial cultures in order to use them in genetic studies. The traditional methods for the isolation of cyanobacteria into culture are well established and described and there are several excellent reviews with detailed information on culturing techniques [less ▲]

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See detailTaxonomic Identification of Cyanobacteria by a Polyphasic Approach
Wilmotte, Annick ULiege; Laughinghouse, Dail Haywood IV; Capelli, Camilla et al

in Kurmayer, Rainer; Sivonen, Kaarina; Wilmotte, Annick (Eds.) et al Molecular Tools for the Detection and Quantification of Toxigenic Cyanobacteria (2017)

In this chapter, we shall discuss the criteria and methods to be adopted for the taxonomic identification and classification of cyanobacteria. This includes a brief introduction of the two Codes of ... [more ▼]

In this chapter, we shall discuss the criteria and methods to be adopted for the taxonomic identification and classification of cyanobacteria. This includes a brief introduction of the two Codes of Nomenclature ruling in parallel on the valid naming of these organisms. We shall then present the major steps important for cyanobacterial taxa identification and their nomenclature. These include: 1) determination of morphology by light microscopy; 2) genetic characterization by single and/or multilocus sequence typing; 3) the assignment of the organism to a taxonomic entity (genus, species, eco- and/or genotype within a species) by reference to, and phylogenetic analysis of, cyanobacterial nucleotide sequences available in public repositories. Ideally, these methods should be accompanied by the determination of other relevant properties (ultrastructural, physiological, biochemical, and ecological characteristics) that may help to define/redefine and circumscribe the cyanobacterial taxon under study. [less ▲]

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See detailMolecular Tools for the Detection and Quantification of Toxigenic Cyanobacteria
Kurmayer, Rainer; Sivonen, Kaarina; Wilmotte, Annick ULiege et al

Book published by John Wiley and sons LTD - This edition first published 2017 (2017)

A guide to state-of-the-art molecular tools for monitoring and managing the toxigenicity of cyanobacteria Runaway climate change has made the monitoring and management of toxigenic organisms in the ... [more ▼]

A guide to state-of-the-art molecular tools for monitoring and managing the toxigenicity of cyanobacteria Runaway climate change has made the monitoring and management of toxigenic organisms in the world’s bodies of water more urgent than ever. In order to influence public policy regarding the detection and quantification of those organisms, it is incumbent upon scientists to clearly demonstrate to policy makers the increase of toxigenic cyanobacteria and the threats they pose. As molecular methods can handle many samples in short time, they are the most reliable, cost-effective tools currently available for tracking cyanotoxicity worldwide. This volume arms scientists with the tools they need to track toxigenicity in surface waters and food supplies and, hopefully, to develop new techniques for managing the spread of toxic cyanobacteria. This book offers the first comprehensive treatment of molecular tools for monitoring cyanotoxicity. Growing out of the findings of the landmark European Cooperation in Science and Technology Cyanobacteria project (CYANOCOST), it provides detailed, practical coverage of the full array of available molecular tools and protocols, from water sampling, nucleic acid extraction, and downstream analysis—including PCR and qPCR based methods—to genotyping (DGGE), diagnostic microarrays, and community characterization using next-gen sequencing techniques. [less ▲]

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See detailDiversity and biogeography of microorganisms in microbial mats of Antarctic lakes
Wilmotte, Annick ULiege; Durieu, Benoit ULiege; Lara, Yannick ULiege et al

in Van de Putte, Anton (Ed.) Book of abstracts: XIIth SCAR Biology Symposium, Leuven, Belgium, 10-14 July 2017. (2017, July)

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms (bacteria, cyanobacteria, microeukaryotes) in lacustrine microbial mats using a combination of techniques ... [more ▼]

The BelSPO project CCAMBIO aims to study the biogeographical distribution of microorganisms (bacteria, cyanobacteria, microeukaryotes) in lacustrine microbial mats using a combination of techniques including microscopic observations, strain isolation and genetic characterisation, and molecular diversity assessments using Next Generation Sequencing of environmental DNA. The samples were collected in different Antarctic and sub-Antarctic biogeographical regions. [less ▲]

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See detailIn Search for Marine Antarctic Cyanobacteria
Lara, Yannick ULiege; Stelmach Pessi, Igor ULiege; Durieu, Benoit ULiege et al

Poster (2017, July)

Cyanobacteria are among the most ancient prokaryotic phyla present on the planet. They are thought to be responsible of two major geological changes and evolutionary process, the Great Oxygenation Event ... [more ▼]

Cyanobacteria are among the most ancient prokaryotic phyla present on the planet. They are thought to be responsible of two major geological changes and evolutionary process, the Great Oxygenation Event and the Endosymbiosis, which supported modern Life. In Polar freshwater and terrestrial ecosystems, cyanobacteria often constitute the major carbon fixers and the base of the food web. They are present in a wide range of habitat from hypersaline lakes to cryoconites. Nevertheless, their presence between the Polar front and Antarctic coast remains enigmatic. For a long time, it has been accepted that they were not present in Antarctic waters (Wilkins et al., 2012). However, they were found in low abundances in two publications, which were investigated the water column (Wilmotte et al., 2002; Wilkins et al., 2013). There is still a lack of information regarding their presence and role in Antarctic coastal waters. In order to investigate the presence of cyanobacteria in Antarctic marine benthos, samples were collected by scuba diving during two expeditions (2015, 2016) in the Lion’s channel, (Terre Adélie, Antarctica). Samples were directly frozen, dried or fixed with formaldehyde. DNA was extracted from one frozen sample and two dried samples. Then, 16S rRNA V3-V4 region was amplified using cyanobacteria-specific primers. Amplicons were sequenced using MiSeq Illumina technology. In parallel, fixed and frozen samples were scrutinized by microscopy. We obtained 14 558 reads, which were related to Cyanobacteria. They clustered into 97 OTUs and belong to six orders (Chroococcales, Nostocales, Oscillatoriales, Pseudanabaenales, Stigonematales, Synechococcales) with a large dominance of Pseudanabaenales. Thirty-one of the cyanobacterial OTUs were 100% identical to sequences of strains isolated from freshwater environment, and air samples from both temperate and Polar regions. Microscope observations revealed the presence of at least 3 cyanobacterial morphotypes including thin filaments, large Oscillatoriales, and a potential symbiotic or opportunist Nostocales. Albeit the low abundance of reads attributed to cyanobacteria, it remains necessary to assess their ecological role in Antarctic coastal waters. [less ▲]

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See detailCyanobacterial Contribution to Travertine Deposition in the Hoyoux River System, Belgium
Kleinteich, Julia; Golubic, Stjepko; Pessi, Igor S. et al

in Microbial Ecology (2017), 74

Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate ... [more ▼]

Travertine deposition is a landscape-forming process, usually building a series of calcareous barriers differentiating the river flow into a series of cascades and ponds. The process of carbonate precipitation is a complex relationship between biogenic and abiotic causative agents, involving adapted microbial assemblages but also requiring high levels of carbonate saturation, spontaneous degassing of carbon dioxide and slightly alkaline pH. We have analysed calcareous crusts and water chemistry from four sampling sites along the Hoyoux River and its Triffoy tributary (Belgium) in winter, spring, summer and autumn 2014. Different surface textures of travertine deposits correlated with particular microenvironments and were influenced by the local water flow. In all microenvironments, we have identified the cyanobacterium Phormidium incrustatum (Nägeli) Gomont as the organism primarily responsible for carbonate precipitation and travertine fabric by combining morphological analysis with molecular sequencing (16S rRNA gene and ITS, the Internal Transcribed Spacer fragments), targeting both field populations and cultures to exclude opportunistic microorganisms responding favourably to culture conditions. Several closely related cyanobacterial strains were cultured; however, only one proved identical with the sequences obtained from the field population by direct PCR. This strain was the dominant primary producer in the calcareous deposits under study and in similar streams in Europe. The dominance of one organism that had a demonstrated association with carbonate precipitation presented a valuable opportunity to study its function in construction, preservation and fossilisation potential of ambient temperature travertine deposits. These relationships were examined using scanning electron microscopy and Raman microspectroscopy. [less ▲]

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See detailAntarctic cyanobacteria: from diversity to genomics
Wilmotte, Annick ULiege

Conference (2017, June 30)

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See detailUnravelling the secret of the resistance of desert strains of Chroococcidiopsis to desiccation and radiation
Billi, Daniela; Fagliarone; Verseux, Cyprien et al

in Van de Putte, Anton (Ed.) Book of abstracts: XIIth SCAR Biology Symposium, Leuven, Belgium, 10-14 July 2017. (2017, June)

Chroococcidiopsis is a unicellular cyanobacterial genus that is growing in extreme dry conditions, either in low or high temperatures. At the lower end of the spectrum, they live as cryptoendoliths in ... [more ▼]

Chroococcidiopsis is a unicellular cyanobacterial genus that is growing in extreme dry conditions, either in low or high temperatures. At the lower end of the spectrum, they live as cryptoendoliths in rocks of the Mc Murdo Dry Valleys in Antarctica where they were discovered by Imre Friedmann, while at the higher end, they grow as hypoliths/endoliths in hot deserts, e.g. Negev, Gobi, Atacama. The capacity of desert strains of Chroococcidiopsis to stabilize their sub-cellular organization is so efficient that, when dried, they can cope with simulated space and Martian conditionsas well as with high doses of ionizing and UV radiations . [less ▲]

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See detailThe BCCM/ULC collection to conserve the biodiversity and study the secondary metabolites of Antarctic cyanobacteria
Lara, Yannick ULiege; Durieu, Benoit ULiege; Renard, Marine et al

in Van de Putte, Anton (Ed.) Book of abstracts: XIIth SCAR Biology Symposium, Leuven, Belgium, 10-14 July 2017. (2017, June)

The BCCM/ULC public collection is funded by the Belgian Science Policy Office since 2011. A Quality Management System ensures that the services of deposits (both public and safe) and distribution are well ... [more ▼]

The BCCM/ULC public collection is funded by the Belgian Science Policy Office since 2011. A Quality Management System ensures that the services of deposits (both public and safe) and distribution are well documented and efficient for the clients’ satisfaction. It has obtained the ISO 9001 certification for deposition and distribution of strains, as part of the multi-site certification for the BCCM consortium. This collection aims to gather a representative portion of the Antarctic cyanobacterial diversity with different ecological origins (limnetic mats, soil crusts, cryoconites, endoliths…) and make it available for researchers to study the taxonomy, evolution, adaptations to harsh environmental conditions, pigments, and genomic make-up. It presently includes 216 cyanobacterial strains, of which 119 are of Antarctic origin (catalogue: http://bccm.belspo.be/catalogues/ulc-catalogue-search). In addition, cyanobacteria are known to produce a wide range of secondary metabolites (e.g. alkaloids, cyclic and linear peptides, polyketides) with bioactive potential. Genome sequencing of 11 strains has been started to enable genome mining for biosynthetic clusters. Pair-read data from illumina MiSeq runs were obtained and submitted to a bioinformatic pipeline dedicated to the assembly of genomes and search of sequences involved in the biosynthesis of secondary metabolites. Gene cluster prediction analysis allowed to characterize 20 clusters of NRPS, PKS and hybrid NRPS-PKS from 2 to 66kb. Surprisingly, none of the characterized operons had previously been described in the literature. [less ▲]

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See detailA strategy to protect reference sites for future microbiology research in Antarctica
Wilmotte, Annick ULiege; Willems, Anne; Verleyen, Elie et al

in Van de Putte, Anton (Ed.) Book of abstracts: XIIth SCAR Biology Symposium, Leuven, Belgium, 10-14 July 2017. (2017, June)

In addition to iconic animals and birds, Antarctica harbours surprisingly diverse microbial communities that drive important biogeochemical processes in virtually all habitats, including ice-free regions ... [more ▼]

In addition to iconic animals and birds, Antarctica harbours surprisingly diverse microbial communities that drive important biogeochemical processes in virtually all habitats, including ice-free regions, ice sheets and subglacial habitats. Recent studies have shown that Antarctic microbiomes may have unique compositions and functions, exhibit biogeographic patterns, and include endemic taxa that have survived in refugia since the continent started to glaciate. Microbial habitats are under constant pressure due to anthropogenic activities, which may introduce non-indigenous microorganisms, via human bodies, clothing, food, cargo, or construction material. New ‘entry points‘ for microbial contamination are a consequence of the increase and diversification of tourism and research stations. Climatic changes might increase the probability of establishment of non-native taxa. The impacts of such introductions are still unknown, but might lead to a loss of the native microbial biodiversity, or its modification. The technical progress in molecular methodologies has generated very sensitive high-throughput methods. They have the potential to describe the microbial communities with unprecedented detail. However, due to the anthropogenic pressure described above, we may be losing the pristine Antarctic areas that would enable scientists to study the native microbial flora, its functions and properties. One tool of the Protocol on Environmental Protection of the Antarctic Treaty that could be specifically used to protect microbial habitats is the creation of inviolate areas where a special entry permit is required (inside ASPAs, for example) and quarantine equipment needs to be used. These zones could be set aside for future research and become extremely valuable as after a few decades, they would be unique examples of pristine habitats, representative of the native microbial diversity and processes. [less ▲]

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