References of "Hiligsmann, Serge"
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See detailEffect of iron nanoparticles synthesized by a sol-gel process on Rhodococcus erythropolis T902.1 for biphenyl degradation
Wannoussa, Wissal; Masy, Thibaut ULg; Lambert, Stéphanie ULg et al

in Journal of Water Resource and Protection (2015), 7

Nanoparticles (NPS) are considered as a new generation of compounds to improve environmental remediation and biological processes. The aim of this study is to investigate the effect of iron NPS ... [more ▼]

Nanoparticles (NPS) are considered as a new generation of compounds to improve environmental remediation and biological processes. The aim of this study is to investigate the effect of iron NPS encapsulated in porous silica (SiO2) on the biphenyl biodegradation by Rhodococcus erythropolis T902.1 (RT902.1). The iron NPS (major iron oxide FexOy form) were dispersed in the porosity of a SiO2 support synthesized by sol-gel process. These Fe/SiO2 NPS offer a stimulating effect on the biodegradation rate of biphenyl, an organic pollutant that is very stable and water-insoluble. This positive impact of NPS on the microbial biodegradation was found to be dependent on the NPS concentration ranging from 10−6 M to 10−4 M. After 18 days of incubation the cultures containing NPS at a concentration of 10−4 M of iron improved RT902.1 growth and degraded 35% more biphenyl than those without NPS (positive control) or with the sole SiO2 particles. Though the microorganism could not interact directly with the insoluble iron NPS, the results show that about 10% and 35% of the initial 10−4 M iron NPS encapsulated in the SiO2 matrix would be incorporated inside or adsorbed on the cell surface respectively and 35% would be released in the supernatant. These results suggest that RT902.1 would produce siderophore-like molecules to attract iron from the porous silica matrix. [less ▲]

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See detailGenome-wide transcriptional analysis suggests hydrogenase- and nitrogenase-mediated hydrogen production in Clostridium butyricum CWBI 1009
Calusinska, Magda; Hamilton, Christopher; Monsieurs, Pieter et al

in Biotechnology for Biofuels (2015), 8(27), 1-16

Background: Molecular hydrogen, given its pollution-free combustion, has great potential to replace fossil fuels in future transportation and energy production. However, current industrial hydrogen ... [more ▼]

Background: Molecular hydrogen, given its pollution-free combustion, has great potential to replace fossil fuels in future transportation and energy production. However, current industrial hydrogen production processes, such as steam reforming of methane, contribute significantly to the greenhouse effect. Therefore alternative methods, in particular the use of fermentative microorganisms, have attracted scientific interest in recent years. However the low overall yield obtained is a major challenge in biological H2 production. Thus, a thorough and detailed understanding of the relationships between genome content, gene expression patterns, pathway utilisation and metabolite synthesis is required to optimise the yield of biohydrogen production pathways. Results: In this study transcriptomic and proteomic analyses of the hydrogen-producing bacterium Clostridium butyricum CWBI 1009 were carried out to provide a biomolecular overview of the changes that occur when the metabolism shifts to H2 production. The growth, H2-production, and glucose-fermentation profiles were monitored in 20 L batch bioreactors under unregulated-pH and fixed-pH conditions (pH 7.3 and 5.2). Conspicuous differences were observed in the bioreactor performances and cellular metabolisms for all the tested metabolites, and they were pH dependent. During unregulated-pH glucose fermentation increased H2 production was associated with concurrent strong up-regulation of the nitrogenase coding genes. However, no such concurrent up-regulation of the [FeFe] hydrogenase genes was observed. During the fixed pH 5.2 fermentation, by contrast, the expression levels for the [FeFe] hydrogenase coding genes were higher than during the unregulated-pH fermentation, while the nitrogenase transcripts were less abundant. The overall results suggest, for the first time, that environmental factors may determine whether H2 production in C. butyricum CWBI 1009 is mediated by the hydrogenases and/or the nitrogenase. Conclusions: This work, contributing to the field of dark fermentative hydrogen production, provides a multidisciplinary approach for the investigation of the processes involved in the molecular H2 metabolism of clostridia. In addition, it lays the groundwork for further optimisation of biohydrogen production pathways based on genetic engineering techniques. [less ▲]

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See detailThermophilic and cellulolytic consortium isolated from composting plants improves anaerobic digestion of cellulosic biomass: toward a microbial resource management approach
Kinet, Romain ULg; Destain, Jacqueline ULg; Hiligsmann, Serge ULg et al

in Bioresource Technology (2015)

A cellulolytic consortium was isolated from a composting plant in order to boost the initial hydrolysis step encountered in anaerobic digestion. Improvement of the cellulose degradation, as well as biogas ... [more ▼]

A cellulolytic consortium was isolated from a composting plant in order to boost the initial hydrolysis step encountered in anaerobic digestion. Improvement of the cellulose degradation, as well as biogas production, was observed for the cultures inoculated with the exogenous consortium. Metagenomics analyses pointed out a weak richness (related to the number of OTUs) of the exogenous consortium induced by the selective pressure (cellulose as sole carbon source) met during the initial isolation steps. Main microbial strains determined were strictly anaerobic and belong to the Clostridia class. During cellulose anaerobic degradation, pH drop induced a strong modification of the microbial population. Despite the fact that richness and evenness were very weak, the exogenous consortium was able to adapt and to maintain the cellulolytic degradation potential. This important result point out the fact that simplified microbial communities could be used in order to increase the robustness of mixed cultures involved in environmental biotechnology. [less ▲]

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See detailInvestigation of the links between mass transfer conditions, dissolved hydrogen concentration and biohydrogen production by the pure strain Clostridium butyricum CWBI1009
Beckers, L.; Masset, J.; Hamilton, C. et al

in Biochemical Engineering Journal (2015), 98

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen ... [more ▼]

Fermentative hydrogen production has often been described as inhibited by its own gas production. In this work, hydrogen production by Clostridium butyricum was investigated in batch Biochemical Hydrogen Potential (BHP) tests and in a 2.5L anaerobic sequenced batch reactor (AnSBR) under different operating conditions regarding liquid-to-gas mass transfer. Through the addition of both stirring up to 400rpm and nitrogen sparging, the yields were enhanced from 1.6 to 3.1molH2molglucose -1 and the maximum hydrogen production rates from 140 to 278mLh-1. These original results were achieved with a pure Clostridium strain. They showed that hydrogen production was improved by a higher liquid-to-gas hydrogen transfer resulting in a lower dissolved hydrogen concentration in the culture medium and therefore in a lower bacterial inhibition. In addition, biohydrogen partitioning between the gas and the liquid phase did not conform to Henry's Law due to critical supersaturation phenomena up to seven-fold higher than the equilibrium conditions. Therefore, dissolved hydrogen concentration should be systematically measured instead of the headspace hydrogen partial pressure. A model was proposed to correlate H2 production yield and rate by the pure C. butyricum strain CWBI1009 with mass transfer coefficient KLa. [less ▲]

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See detailProduction de biohydrogène à partir de biomasses
Hiligsmann, Serge ULg

Scientific conference (2014, October 23)

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See detailMontage de projets de Recherche et d’Innovation : A la recherche de financements
Hiligsmann, Serge ULg

Scientific conference (2014, October 23)

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See detailTraitement biologique anaérobie des déchets organiques : Comment tirer profit de la biomasse
Hiligsmann, Serge ULg

Scientific conference (2014, October 09)

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See detailMesophilic biohydrogen production by Clostridium butyricum CWBI1009 in trickling biofilter reactor
Puhulwella, Rathnasiri G.; Beckers, Laurent; Delvigne, Frank ULg et al

in International Journal of Hydrogen Energy (2014), 39

This study investigates the mesophilic biohydrogen production from glucose using a strictly anaerobic strain, Clostridium butyricum CWBI1009, immobilized in a trickling bed sequenced batch reactor (TBSBR ... [more ▼]

This study investigates the mesophilic biohydrogen production from glucose using a strictly anaerobic strain, Clostridium butyricum CWBI1009, immobilized in a trickling bed sequenced batch reactor (TBSBR) packed with a Lantec HD Q-PAC® packing material (132 ft2/ft3 specific surface). The reactor was operated for 62 days. The main parameters measured here were hydrogen composition, hydrogen production rate and soluble metabolic products. pH, temperature, recirculation flow rate and inlet glucose concentration at 10 g/L were the controlled parameters. The maximum specific hydrogen production rate and the hydrogen yield found from this study were 146 mmol H2/L.d and 1.67 mol H2/mol glucose. The maximum hydrogen composition was 83%. Following a thermal treatment, the culture was active without adding fresh inoculum in the subsequent feeding and both the hydrogen yield and the hydrogen production rate were improved. For all sequences, the soluble metabolites were dominated by the presence of butyric and acetic acids compared to other volatile fatty acids. The results from the standard biohydrogen production (BHP) test which was conducted using samples from TBSBR as inoculum confirmed that the culture generated more biogas and hydrogen compared to the pure strain of C. butyricum CWBI1009. The effect of biofilm activity was studied by completely removing (100%) the mixed liquid and by adding fresh medium with glucose. For three subsequent sequences, similar results were recorded as in the previous sequences with 40% removal of spent medium. The TBSBR biofilm density varied from top to bottom in the packing bed and the highest biofilm density was found at the bottom plates. Moreover, no clogging was evidenced in this packing material, which is characterized by a relatively high specific surface area. Following a PCA test, contaminants of the Bacillus genus were isolated and a standard BHP test was conducted, resulting in no hydrogen production. [less ▲]

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See detailFermentation profile of Saccharomyces cerevisiae and Candida tropicalis as starter cultures on barley malt medium
Alloue-Boraud, Mireille; N’Guessan, Kouadio; Djeni, Théodore et al

in Journal of Food Science & Technology (2014)

Saccharomyces cerevisiae C8-5 and Candida tropicalis F0-5 isolated from traditional sorghum beer were tested for kinetic parameters on barley malt extract, YPD (863 medium) and for alcohol production. The ... [more ▼]

Saccharomyces cerevisiae C8-5 and Candida tropicalis F0-5 isolated from traditional sorghum beer were tested for kinetic parameters on barley malt extract, YPD (863 medium) and for alcohol production. The results showed that C. tropicalis has the highest maximum growth rate and the lowest doubling time. Values were 0.22 h-1 and 0.32 h-1 for maximum growth rate, 3 h 09 min and 2 h 09 min for doubling time respectively on barley malt extract and YPD. On contrary, glucose consumption was the fastest with S. cerevisiae (-0.36 g/l/h and -0.722 g/l/h respectively on barley malt extract and YPD). When these two yeasts were used as starters in pure culture and co-culture at proportion of 1:1 and 2:1 (cell/cell) for barley malt extract fermentation, we noticed that maltose content increased first from 12.12 g/l to 13.62-16.46 g/l and then decreased. The highest increase was obtained with starter C. tropicalis + S. cerevisiae 2:1. On contrary, glucose content decreased throughout all the fermentation process. For all the starters used, the major part of the ethanol was produced at 16 h of fermentation. Values obtained in the final beers were 11.4, 11.6, 10.4 and 10.9 g/l for fermentation conducted with S. cerevisiae, C. tropicalis, C. tropicalis + S. cerevisiae 1:1 and C. tropicalis + S. cerevisiae 2:1. Cell viability measurement during the fermentation by using flow cytometry revealed that the lowest mean channel fluorescence for FL3 (yeast rate of death) was obtained with C. tropicalis + S. cerevisiae 2:1 after 48 h of fermentation. [less ▲]

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See detailEffect of metal nanoparticles encapsulated in porous silica on the biphenyl biodegradation by Rhodococcus erythropolis T902.1
Wannoussa, Wissal ULg; Hiligsmann, Serge ULg; Heinrichs, Benoît ULg et al

Poster (2014, May 01)

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are ... [more ▼]

Biphenyl is stable and highly hydrophobic, thus having a low availability for degrading microorganisms, which need an aqueous environment for their growth. As a consequence, bioremediation processes are very limited. However, a few studies showed that using a low metal concentration accelerates the biodegradation of pollutants (Yeom and Yoo1997). Nanoparticles are considered as a new generation of compounds to improve environmental remediation and biological processes (Beckers et al. 2013; Zhang 2003). This paper investigated the enhancement effect of nanometre-sized metallic Cu, Ag, Pd or Co, on the biphenyl biodegradation by Rhodococcus erythropolis T902.1. Have been synthesized by a sol–gel process (Lambert et al. 2004). These nanoparticles (NP) of about 2–3 nm were encapsulated in porous silica (SiO2) and were added at low concentration (10-4M) in the M284 minimal medium with 500 ppm biphenyl as source of carbon and energy. The cultures containing Pd or Co produced 30% more biphenyl degraded with a higher Rhodococcus growth than those without NP (positive control) or with silica particles only. On the contrary, the presence of 10-4 M Cu or Ag nanoparticles showed an inhibitory effect on bacterial growth and biphenyl degradation compared to the positive. [less ▲]

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See detailEffect of encapsulated nanoparticles on thermophillic anaerobic digestion
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2014, February 07)

Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science ... [more ▼]

Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate). Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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See detailLack of isocitrate lyase in Chlamydomonas leads to changes in carbon metabolism and in the response to oxidative stress under mixotrophic growth.
Plancke, Charlotte; Vigeolas, Hélène ULg; Hohner, Ricarda et al

in The Plant journal : for cell and molecular biology (2014), 77(3), 404-417

Isocitrate lyase is a key enzyme of the glyoxylate cycle. This cycle plays an essential role in cell growth on acetate, and is important for gluconeogenesis as it bypasses the two oxidative steps of the ... [more ▼]

Isocitrate lyase is a key enzyme of the glyoxylate cycle. This cycle plays an essential role in cell growth on acetate, and is important for gluconeogenesis as it bypasses the two oxidative steps of the tricarboxylic acid (TCA) cycle in which CO2 is evolved. In this paper, a null icl mutant of the green microalga Chlamydomonas reinhardtii is described. Our data show that isocitrate lyase is required for growth in darkness on acetate (heterotrophic conditions), as well as for efficient growth in the light when acetate is supplied (mixotrophic conditions). Under these latter conditions, reduced acetate assimilation and concomitant reduced respiration occur, and biomass composition analysis reveals an increase in total fatty acid content, including neutral lipids and free fatty acids. Quantitative proteomic analysis by 14 N/15 N labelling was performed, and more than 1600 proteins were identified. These analyses reveal a strong decrease in the amounts of enzymes of the glyoxylate cycle and gluconeogenesis in parallel with a shift of the TCA cycle towards amino acid synthesis, accompanied by an increase in free amino acids. The decrease of the glyoxylate cycle and gluconeogenesis, as well as the decrease in enzymes involved in beta-oxidation of fatty acids in the icl mutant are probably major factors that contribute to remodelling of lipids in the icl mutant. These modifications are probably responsible for the elevation of the response to oxidative stress, with significantly augmented levels and activities of superoxide dismutase and ascorbate peroxidase, and increased resistance to paraquat. [less ▲]

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See detailImprovement of fermentative biohydrogen production by Clostridium butyricum CWBI1009 in sequenced-batch, horizontal fixed bed and biodisc-like anaerobic reactors with biomass retention
Hiligsmann, Serge ULg; Beckers, Laurent; Masset, Julien et al

in International Journal of Hydrogen Energy (2014), 39

A horizontal tubular fixed bed bioreactor (HFBR) and an anaerobic biodisc-like reactor (AnBDR) were designed to both fix Clostridium biomass and enable rapid transfer of the hydrogen produced to gas phase ... [more ▼]

A horizontal tubular fixed bed bioreactor (HFBR) and an anaerobic biodisc-like reactor (AnBDR) were designed to both fix Clostridium biomass and enable rapid transfer of the hydrogen produced to gas phase in order to decrease the strong effect of H2 partial pressure and H2 supersaturation on the performances of Clostridium strains. The highest H2 production rate (703 mL H2/L.h) and yield (302 mL/g glucose consumed i.e. 2.4 mol/mol) with the pure culture were recorded in the AnBDR with 300 mL culture medium (total volume 2.3 L) at pH 5.2 and a glucose loading rate of 2.87 g/L.h. These results are about 2.3 and 1.3-fold higher than those achieved in the same bioreactor with 500 mL liquid medium and with the same glucose consumption rate. Therefore, our experimentations and a short review of the literature reported in this paper emphasize the relevance of performing bioreactors with high L/G transfer. [less ▲]

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See detailEnhancement of thermophillic anaerobic digestion of methane by metal nanoparticles encapsulated in porous silica
Al-Ahmad, Alaa Eddin ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

Poster (2013, December 05)

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production ... [more ▼]

Increased demand and progressive depletion of fossil fuels, and worldwide concerns about greenhouse gas emissions have resulted in the development of promising technologies for renewable energy production. Therefore, potential alternatives for energy generation are intensively studied. One option is the use of biomass feedstock for the production of biogas through anaerobic digestion. This process is a biochemical technological process for the treatment of a wide range of feedstocks (e.g. organic fraction of municipal waste, animal manure and slurry, agricultural crops, etc.) to produce methane-rich biogas which can be used in replacement of fossil fuels in both heat and power generation and as a vehicle fuel. However, there are critical issues, which need to be addressed to make the production of bio-methane techno-economically viable and ecologically acceptable. One of the most important issues is the effect of trace metals addition on anaerobic digestion. These metals can be stimulatory, inhibitory, or even toxic for biochemical reactions, depending on their concentrations. As reported in literature, Ni, Co and Fe are all involved in the methane production biochemical process and serve as cofactors in enzymes which are involved in the biochemistry of methane formation (Zandvoort et al., 2006). Recently, enormous interest has been focused on biological applications of metal nanoparticles NPs due to their small size, high specified surface and their great potential in application to many science fields. The most studied process concerns zero valent palladium and iron NPs improving anaerobic biodegradation of chlorinated hydrocarbons (Windt et al., 2005). Moreover, investigation carried out in our lab showed that iron NPs encapsulated in silicate matrix may enhance hydrogen production by Clostridium butyricum (Beckers et al., 2013). Nevertheless the influences of metal NPs on methane producing anaerobic digestion have seldom been investigated. The present work investigates the enhancement effect of seven different metal NPs on methane production during the thermophilic anaerobic digestion. NPs of Cu, Pd, Pt, Ni, Co, Ag and Fe encapsulated in porous silica (SiO2) to prevent their coagulation and agglomeration, were added at concentration of 10-5mol/L in batch test (125ml serum bottles containing 70mL culture medium with 5g/L acetate monohydrate as the sole carbon substrate. Nickel, cobalt and iron NPs improved methane production from acetate. To confirm the previous results, the NPs were tested at different concentrations (10-4, 10-5, and 10-6 mol/L) with starch and glucose substrates. The results show that the impact increases with the increase of NPs concentrations up to 10-4 mol/L. The modified Gompertz equation was applied to describe the effect of NPs on anaerobic digestion. According to this model, the kinetic of methane production was particularly affected by nanoparticles addition. The values of the maximum methane production rate MPR (ml/day) was significantly higher 72.5% with nickel NPs at a concentration of 10-4 mol/L than the control without NPs. [less ▲]

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