References of "Wilmotte, Annick"
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See detailAn efficient DNA isolation protocol for filamentous cyanobacteria of the genus Arthrospira
Morin, Nicolas ULg; Vallaeys, Tatiana; Hendrickx, Larissa et al

in Journal of Microbiological Methods (2010), 80

Thanks to their photosynthetic and nutritive properties, cyanobacteria of the Arthrospira genus are of interest as food supplements, as efficient oxygen producing life support system organisms for manned ... [more ▼]

Thanks to their photosynthetic and nutritive properties, cyanobacteria of the Arthrospira genus are of interest as food supplements, as efficient oxygen producing life support system organisms for manned space flight, and for the production of biofuels. Despite these potential valuable applications, full genome sequences and genetic information in general on Arthrospira remain scarce. This is mainly due to the difficulty to extract sufficient high molecular weight nucleic acids from these filamentous cyanobacteria. In this article, an efficient and reproducible DNA extraction procedure for cyanobacteria of the genus Arthrospira was developed. The method is based on the combination of a soft mechanical lysis with enzymatic disruption of the cell wall. The comparison with other extraction protocols clearly indicates that this optimised method allows the recovery of a larger amount of DNA. Furthermore, the extracted DNA presents a high molecular weight, a reduced degradation and an excellent overall quality. It can be directly used for molecular biology purposes such as PCR, and clone library construction. [less ▲]

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See detailThe diversity of clostridial hydrogenases revealed by genome sequencing projects
Calusinska, Magdalena ULg; Wilmotte, Annick ULg; Joris, Bernard ULg

Poster (2009, December 15)

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean ... [more ▼]

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean, and transportable energy carrier. Some microorganisms can produce hydrogen during a reversible reduction of protons to dihydrogen, a reaction which is catalyzed by the enzyme hydrogenases. On the basis of their bimetallocenter composition, hydrogenases are divided into three main groups, phylogenetically not related: [NiFe] hydrogenases, [Fe] only hydrogenases and FeS cluster free hydrogenases. The latter were described in methanogenic Archaea only. [NiFe] hydrogenases, composed of at least two subunits are well characterized and widely distributed between Archaea and Bacteria. However, only a few representatives of Clostridium sp. possess this type of enzyme. On the other hand, much less is known about the [Fe] only hydrogenases, that are usually monomeric enzymes and restricted to Bacteria and a few eukaryotic species. Genome sequencing projects gave a completely new insight into the diversity of forms of putative [Fe] only hydrogenases within the genus Clostridium. With the use of bioinformatic tools, we have described the unusual modularity of forms of these enzymes, from monomeric to tetrameric with a different number of accessory domains reacting with diverse redox partners. This fact seems to support the central role of hydrogenases in cell metabolism and quick adaptation of the host to changing environmental conditions. Moreover, the presence of multiple putative operons encoding for multisubunit [FeFe] hydrogenases is highlighting the fact that hydrogen metabolism is very complex in the Clostridium genus. [less ▲]

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See detailCyanobacterial 
molecular 
diversity 
and distribution 
in 
microbial 
mats from 
antarctic 
lakes
De Carvalho Maalouf, Pedro ULg; Lambion, Alexandre ULg; Zakhia, Frédéric et al

Poster (2009, December 11)

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the ... [more ▼]

The coastal deglaciated areas of Antarctica hold lakes and other water bodies with a wide spectrum of limnological conditions. Aquatic habitats offer milder conditions to the microorganisms, which are the only permanent inhabitants of this glacial desert. Among them, cyanobacteria are the first photosynthetic colonisers, sometimes forming thick, cohesive and pigmented benthic mats. In the frame of the BELSPO AMBIO project (Antarctic Microbial BIOdiversity, influence of geographical and ecological factors, www.ambio.ulg.ac.be), we have obtained benthic mat samples coming from lakes from various coastal regions of the continent (MERLIN 2007 and BELARE 2007 field campaigns and by collaborations). We have investigated cyanobacterial molecular diversity via Polymerase Chain Reaction and Denaturating Gradient Gel Electrophoresis (PCR-DGGE) on a set of 80 samples. We couple the numerical analysis of the obtained band patterns with the phylogenetic analysis of the sequences, and by using multivariate analysis, we will assess the role of the ecological and geographical factors shaping the distribution and the diversity of cyanobacteria. Preliminary results of the analysis of 13 samples seem to indicate that lakes separated by a small distance have different cyanobacterial communities, highlighting the importance of ecological factors. Fifty per cent of the obtained Operational Taxonomic Units (OTUs) are potentially endemic to Antarctica while others seem to have a global distribution. The completed study will give us a wide scale view on the distribution and the diversity of cyanobacteria in two biogeographical zones: Continental Antarctica and Maritime Antarctica. Finally, our studies will supply new data and arguments for the ongoing “everything is everywhere, but the environment selects” debate concerning microbial biogeography. [less ▲]

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See detailApplication of molecular techniques to monitor the evolution of bacterial consortia composed of Clostridium sp. in a hydrogen producing bioreactor
Calusinska, Magdalena ULg; Savichtcheva, Olga; Joris, Bernard ULg et al

Poster (2009, December 11)

Our current dependence on fossil fuels as the primary energy source contributes to global climate change, environmental degradation and health problems. Hydrogen offers a tremendous potential as a clean ... [more ▼]

Our current dependence on fossil fuels as the primary energy source contributes to global climate change, environmental degradation and health problems. Hydrogen offers a tremendous potential as a clean, renewable energy currency and it is compatible with electrochemical and combustion processes for energy conversion without producing carbon – based emissions. Many microorganisms, especially photosynthetic as well as facultative and anaerobic bacteria have been reported to produce large amounts of hydrogen from soluble and insoluble biomass. Clostridia, being obligate anaerobes, are capable of biogas production during ‘dark fermentation’ of a wide range of carbohydrates. In this ARC project, entitled Micro – H2 we have focused on a new direction in bio – hydrogen production systems which is the use of mixed cultures of microorganisms (consortia). We expect that the combination of complementary metabolisms could significantly increase the efficiencies of mixed systems compared to monocultures. However, a few fundamental studies need to be carried out in order to investigate and improve the stability of microbial populations involved in the processes. It is now recognised that molecular microbial ecology tools provide the scientific basis to monitor the processes used in environmental biotechnology. To characterize the diversity of bacterial communities, quantitative techniques such as Real – Time Quantitative PCR and FISH (Fluorescence in situ hybridization) and semi – quantitative DGGE (Denaturing Gradient Gel Electrophoresis) have been optimized and applied on different bioreactor samples. This approach enabled for the temporal monitoring of the evolution of bacterial consortia, both in terms of species dominance and their metabolic activity. Molecular analysis of bacterial consortia allowed for careful examination of interactions between different bacterial species within a consortium, which is crucial in the stabilization of the hydrogen production process. [less ▲]

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See detailThe diversity of Clostridial hydrogenases and biohydrogen production
Calusinska, Magdalena ULg; Savichtcheva, Olga; Masset, Julien ULg et al

Poster (2009, June 18)

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean ... [more ▼]

Molecular hydrogen is a key intermediate in metabolomic interactions of a wide range of microorganisms. Hydrogen is also regarded as a key component in future energy systems as it is a sustainable, clean, and transportable energy carrier. Some microorganisms can produce hydrogen during a reversible reduction of protons to dihydrogen, a reaction which is catalyzed by hydrogenases [1]. Hydrogenases belong to an iron – sulphur protein family, that contains active sites consisting of inorganic sulfide and iron atoms bound to the polypeptide chain. On the basis of their bimetallocenter composition hydrogenases are divided into three main groups, phylogenetically not related: [NiFe] hydrogenases, [Fe] only hydrogenases and ‘metal – free hydrogenases’ which were described in methanogenic Archaea only. [NiFe] hydrogenases, composed of at least two subunits are well characterized and widely distributed between Archaea and Bacteria but only a few representatives of Clostridium possess this type of enzyme. On the other hand, [Fe] only hydrogenases, being usually monomeric enzymes and restricted to Bacteria and a few eukaryotic species are far less described. These proteins, being omnipresent catalysts of many biological reactions, are especially abundant in Clostridia. The physiological function of Clostridial [Fe] only hydrogenases is to dispose under the form of hydrogen, of the excess of reducing power generated during the fermentation of carbohydrates. The unusual diversity of forms of [Fe] only hydrogenases within Clostridia seems to support the central role of this enzyme in cell metabolism and to facilitate the quick adaptation of the host to changing environmental conditions. Moreover, the presence of multiple putative operons encoding for multisubunit [Fe] only hydrogenases in the genomes of sequenced Clostridium spp. is highlighting the need to study the new, not yet described function of these ostensibly simple proteins. In this project, we have focused our effort on the molecular characterization of key enzymes involved in the process of biohydrogen production with a special interest in Clostridium species. By applying molecular techniques on samples from different kinds of bioreactors, we want to select highly productive species in terms of hydrogen generation. We also believe that gene expression profiling will provide new data on the possible function and activity of different hydrogenases involved in the process. The better understanding of hydrogen metabolism is essential for its sustainable production. [less ▲]

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See detailThe biodiversity of cyanobacteria in Antarctic microbial mats
Wilmotte, Annick ULg; Fernandez-Carazo, Rafael; Zakhia, Frederic et al

Conference (2009)

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See detailDarwin en Antarctique: diversité et phylogénie
Wilmotte, Annick ULg

in Bulletin de la Société Royale des Sciences de Liège (2009), 78

In the first part, I imagine that Charles Darwin has visited Livingston Island in the Antarctic Peninsula. In the first part, our research on the cyanobacterial diversity in the region of the Belgian ... [more ▼]

In the first part, I imagine that Charles Darwin has visited Livingston Island in the Antarctic Peninsula. In the first part, our research on the cyanobacterial diversity in the region of the Belgian research station Princess Elisabeth is presented. [less ▲]

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See detailSeasonal cyanobacterial dynamics in a mesoeutrophic reservoir: microscopic counts and DGGE (Denaturing Gradient Gel Electrophoresis)
Willame, Raphael; Boutte, Christophe; Grubisic, Stana ULg et al

in Algological Studies (2009), 129

The seasonal planktic cyanobacterial dynamics was assessed during the year 2000 by microscopic and DGGE techniques, on the basis of 22 samples collected from the Haute-Sûre reservoir (Grand-Duchy of ... [more ▼]

The seasonal planktic cyanobacterial dynamics was assessed during the year 2000 by microscopic and DGGE techniques, on the basis of 22 samples collected from the Haute-Sûre reservoir (Grand-Duchy of Luxembourg). Microscopic investigations were carried out according to the standard Utermöhl procedure while 16S rRNA gene fragments obtained by semi-nested PCR were subsequently separated by DGGE. Sequencing of selected excised bands was performed to genotypically define the cyanobacterial assemblages. The dynamics of cyanobacterial communities obtained by both approaches were compared. Several discordances were pointed out. The counting procedure failed to detect cyanobacteria with small dimensions or in very low abundances, whereas DGGE had a lower detection limit when cyanobacteria were scarce (e.g. in spring) and performed better for the study of picosized forms. Generally, only the dominant cyanobacteria were revealed by these two methods. Actually, both techniques appeared to be complementary rather than equivalent. This study underlines the necessity to use multidisciplinary approaches to obtain a more complete view of the microbial diversity and of the community structure [less ▲]

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See detailMicrobiological and ecological responses to global environmental changes in polar regions (MERGE): An IPY core coordinating project
Naganuma, Takeshi; Wilmotte, Annick ULg

in Polar Sciences (2009), 3

An integrated program, ‘‘Microbiological and ecological responses to global environmental changes in polar regions’’ (MERGE), was proposed in the International Polar Year (IPY) 2007e2008 and endorsed by ... [more ▼]

An integrated program, ‘‘Microbiological and ecological responses to global environmental changes in polar regions’’ (MERGE), was proposed in the International Polar Year (IPY) 2007e2008 and endorsed by the IPY committee as a coordinating proposal. MERGE hosts original proposals to the IPYand facilitates their funding. MERGE selected three key questions to produce scientific achievements. Prokaryotic and eukaryotic organisms in terrestrial, lacustrine, and supraglacial habitats were targeted according to diversity and biogeography; food webs and ecosystem evolution; and linkages between biological, chemical, and physical processes in the supraglacial biome. [less ▲]

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See detailAstrobiologie cours-conférence du Collège Belgique (ARB)
Javaux, Emmanuelle ULg; Wilmotte, Annick ULg; Claeys, Philippe et al

Learning material (2009)

cours enregistrés sur le site de l'ARB (http://www.academieroyale.be/)

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See detailDiversité et limites de la vie
Wilmotte, Annick ULg; Javaux, Emmanuelle ULg

Conference (2009)

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See detailA new approach to analyze genotypes of colony-forming cyanobacteria from environmental samples.
Lara, Yannick ULg; BOUTTE, Christophe; PERETYATKO, Anatoly et al

Poster (2008, August 31)

Several studies have shown the efficiency of sequences as rRNA-ITS, cpcBA, rbcLX and other housekeeping genes to study taxonomy [1, 2, 3], population, community structure of cyanobacteria, or for Multi ... [more ▼]

Several studies have shown the efficiency of sequences as rRNA-ITS, cpcBA, rbcLX and other housekeeping genes to study taxonomy [1, 2, 3], population, community structure of cyanobacteria, or for Multi Locus Sequence Analysis [4]. Recently, the genotypic analysis of single colonies and single filaments directly isolated from the environment has been carried out by other authors. It appears that different genotypes of Microcystis are present in one population in one lake. Besides, succession of toxic and non-toxic genotypes may have a critical influence on toxin concentrations during the blooms [5]. Genotypic analysis of colony-forming cyanobacteria requires enough DNA. So far, the genotypes of environmental single colonies of Microcystis were characterized on the basis of one or two PCR [6]. As the DNA content of one single colony only allows for a few PCR reactions, we have developed a new approach using Whole Genome Amplification with Phi29 polymerase to allow for the Multi Locus Sequences Typing analysis of a single colony or filament. For the first time, we were able to amplify and sequence more than one locus of the genome of a single colony of Microcystis. In addition, we have obtained the first sequences of rpoC1, rbcLX and rRNA-ITS from a single colony of the genus Woronichinia ( identified by microscopy). This approach allows to work with a small amount of DNA, and represents a concrete answer to the lack of data on non-cultivable cyanobacteria. This research is supported by the Belgian Science policy under the science for a sustainable development (SSD) and Fonds de la Recherche Scientifique-FNRS with a FRIA fellowship. References: [1] Otsuka S, et al (1999) FEMS Microbiology Letters 172 15-21 [2] Gugger M, et al (2002) Int J Syst Evol Microbiol 52 1867-1880 [3] Haverkamp T, et al (2008) Environmental Microbiology 10(1) 174-188 [4] Lodders N, et al (2005) Environmental Microbiology 7 (3) 434-442 [5] Kardinaal E, and Visser P (2005) In Harmfuf cyanobacteria, Springer Dordrecht pp 41-64 [6] Janse I, et al (2004) Appl Environm Microbiol 70 (7) 3979–3987 [less ▲]

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See detailCyanobacteria from benthic mats of Antarctic lakes as a source of new bioactivities
Biondi, Natascia; Tredici, Mario; Taton, Arnaud et al

in Journal of Applied Microbiology (2008), 105(1), 105-115

Aims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results ... [more ▼]

Aims: To exploit the cyanobacterial diversity of microbial mats growing in the benthic environment of Antarctic lakes for the discovery of novel antibiotic and antitumour activities. Methods and results: In all, 51 Antarctic cyanobacteria isolated from benthic mats were cultivated in the laboratory by optimizing temperature, irradiance and mixing. Productivity was generally very low (£60 mg l)1 d)1) with growth rates (l) in the range of 0Æ02–0Æ44 d)1. Growth rates were limited by photosensitivity, sensitivity to air bubbling, polysaccharide production or cell aggregation. Despite this, 126 extracts were prepared from 48 strains and screened for antimicrobial and cytotoxic activities. Seventeen cyanobacteria showed antimicrobial activity (against the Gram-positive Staphylococcus aureus, the filamentous fungus Aspergillus fumigatus or the yeast Cryptococcus neoformans), and 25 were cytotoxic. The bioactivities were not in accordance with the phylogenetic grouping, but rather strain-specific. One active strain was cultivated in a 10-l photobioreactor. Conclusions: Isolation and mass cultivation of Antarctic cyanobacteria and LCMS (liquid chromatography ⁄ mass spectrometry) fractionation of extracts from a subset of those strains (hits) that exhibited relatively potent antibacterial and ⁄ or antifungal activities, evidenced a chemical novelty worthy of further investigation. Significance and impact of the study: Development of isolation, cultivation and screening methods for Antarctic cyanobacteria has led to the discovery of strains endowed with interesting antimicrobial and antitumour activities. [less ▲]

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See detailDiversity of planktonic cyanobacteria and microcystin occurrence in Polish water bodies investigated using a polyphasic approach
Boutte, Christophe; Mankiewicz-Boczek, Joanna; Komarkova, Jarka et al

in Aquatic Microbial Ecology (2008), 51

Microscopic measurements of fresh biomass and 16S rRNA gene sequences from clone libraries and denaturing gradient gel electrophoresis (DGGE) were used to investigate cyanobacterial diversity in Polish ... [more ▼]

Microscopic measurements of fresh biomass and 16S rRNA gene sequences from clone libraries and denaturing gradient gel electrophoresis (DGGE) were used to investigate cyanobacterial diversity in Polish water bodies in 2002. In addition, measurements of microcystin (MC) concentrations were made. Thirty water samples were taken from 11 water bodies; of these samples, 18 were obtained from the Sulejow Reservoir during regular monitoring from June to October. Intraand extracellular MC concentrations in Sulejow samples were measured by high performance liquid chromatography (HPLC). The extracellular MC concentration was assessed using a protein phosphatase inhibition assay (PPIA) in additional lakes. Additionally, physicochemical parameters were measured (total nitrogen [TN], total phosphorus [TP], TN:TP ratio, chlorophyll a concentration, temperature). In Sulejow, high intracellular MC concentrations corresponded to large cyanobacterial biovolumes and to low TN:TP ratios. In the other lakes, extracellular MCs were not linked to any measured parameters. The combination of the microscopic and molecular data showed that Aphanizomenon and Microcystis were the dominant genera during the summer period in the Sulejow Reservoir. At the genetic level, there was a succession of 2 different operational taxonomic units (OTUs) belonging to the lineage Anabaena/Aphanizomenon. In the other water bodies, the most frequent populations were Aphanizomenon, Anabaena, Microcystis and Planktothrix. Small populations of Romeria, Snowella, Woronichinia, Limnothrix and Pseudanabaena were observed, and an enigmatic cluster affiliated with Prochlorothrix was genetically retrieved. Anabaena and Microcystis were presumed to be the main genera responsible for the MC production. [less ▲]

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See detailAlgal blooms: emerging problem for health and sustainable use of surface waters
Wilmotte, Annick ULg; Descy, Jean-Pierre; Vyverman, Wim

Report (2008)

The BBLOOMS project was a two-year program, which was primarily proposed to make a first assessment of the extent of present cyanobacterial blooms in Belgium and of the potential threat for the surface ... [more ▼]

The BBLOOMS project was a two-year program, which was primarily proposed to make a first assessment of the extent of present cyanobacterial blooms in Belgium and of the potential threat for the surface water resources. In this study, we addressed several aspects: (i) the extent and phenology of nuisance blooms in multiple-use Belgian surface waters, (ii) the taxonomic diversity of bloom-forming cyanobacteria, using traditional and genetic tools, (iii) the use of genetic markers to estimate whether the organisms are potentially toxic, (iv) the measurement of toxin concentration in field samples, and (v) the relationship between environmental variables and nuisance blooms in selected water bodies. Most field samples came from 4 reference lakes (Blaarmeersen lake in Flanders and three pre-dam lakes of Eau d’Heure in Wallonia) that were monitored intensively for 2 years. Twenty-three samples were taken for Blaarmeersen, in a continuous manner. Seventy-three samples were studied for the Eau d’Heure complex, but only when proliferations were observed. Additional samples were provided by summer samplings in a series of small lakes in Flanders carried out by the University of Gent. As this was insufficient to obtain a global view of the phenomenon, we have built BLOOMNET, a network of water managers and users, who received information about cyanobacterial blooms and how to collect them for subsequent analysis. The network contributed about forty samples from all regions. [less ▲]

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See detailDiversité moléculaire des cyanobactéries planctonniques dans les eaux de surface belges
Lara, Yannick ULg; Lambion, Alexandre ULg; Simon, Patricia ULg et al

Poster (2008, April 02)

Les développements massifs de cyanobactéries ou ‘blooms’ sont devenus un phénomène récurrent et de plus en plus important dans les eaux douces du monde entier durant la dernière décennie. Ces ... [more ▼]

Les développements massifs de cyanobactéries ou ‘blooms’ sont devenus un phénomène récurrent et de plus en plus important dans les eaux douces du monde entier durant la dernière décennie. Ces efflorescences présentent des risques potentiels majeurs pour la santé humaine et animale et interfèrent négativement avec l'utilisation des eaux de surface par exemple, pour le captage d'eau potable, les loisirs nautiques, l'irrigation, les exploitations piscicoles. Entre 25 et 70% des blooms sont toxiques. Comme beaucoup de pays la Belgique n'a pas échappé au problème des efflorescences de cyanobactéries toxiques, mais il y a encore relativement peu de données. Durant la dernière décennie, trois projets européens et nationaux (MIDICHIP 1999-2003, B-BLOOMS 2003-2005, B-BLOOMS 2 2007-2011) se sont intéressés à la diversité des cyanobactéries dans les eaux de surfaces belges. Nous présentons ici un arbre phylogénétique élaboré à partir d’ un pool de 249 séquences partielles du gène codant pour l’ARNr 16S obtenu à partir de 31 échantillons d’eaux belges issus de ces projets. Cet arbre représente la mise à jour d’une base de données qui constitue l’inventaire des cyanobactéries d’eaux douces belges. Cette base de données permet le suivi de l’évolution de la diversité observable de ces organismes en Belgique et la surveillance de l’apparition d’espèces tropicales comme conséquence aux changements climatiques globaux. [less ▲]

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