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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 detailBiohydrogen production from anaerobic digestion of carbohydrate organic matter.
Hiligsmann, Serge ULg; Masset, Julien ULg; Beckers, Laurent ULg et al

Poster (2008, December 16)

Hydrogen has received wide attention in the last decade as a clean energy vector. The major advantage of energy from hydrogen is the zero carbon emissions, since the utilization of hydrogen, either via ... [more ▼]

Hydrogen has received wide attention in the last decade as a clean energy vector. The major advantage of energy from hydrogen is the zero carbon emissions, since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. At industrial scale, steam reformation of methane is currently the major hydrogen producing process. However recently, increasing interest has been paid on biological production of hydrogen gas. Indeed, biohydrogen generation from renewable biomass would reduce dependence on fossil fuel, decrease the carbon dioxide emissions and produce usable bioenergy. Biological production of hydrogen using anaerobic bacteria is an exciting and promising new area of technology development that offers the potential production of usable hydrogen from a variety of renewable resources such as carbohydrates from agriculture or agro-food industries. This biological system is called dark fermentation and the most interesting bacteria strains are Clostridium sp. The investigations carried out at CWBI involve selection and characterization of bacteria strains, optimization of the biotechnological process and design of highly efficient bioreactors. [less ▲]

Detailed reference viewed: 33 (8 ULg)
See detailArabidopsis halleri, a model system to understand zinc homeostasis in plants
Hanikenne, Marc ULg; Talke, Ina N.; Hamilton, Christopher ULg et al

Poster (2007, November 16)

Detailed reference viewed: 16 (1 ULg)