References of "Hiligsmann, Serge"
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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), (0),

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 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 detailANAEROBIC DIGESTION OF ORGANIC WASTES FROM AGRO-FOOD ACTIVITIES IN TUNISIA
Mhiri, F; Hiligsmann, Serge ULg; Sayahi, L. et al

Poster (2013, October 01)

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See detailMONITORING OF ANAEROBIC DIGESTION IN MSW LANDFILLS IN TUNISIA
Mhiri, F.; Hiligsmann, Serge ULg; Sayahi, L. et al

in Proceedings Sardinia 2013 (2013, October)

The monitoring of two controlled landfills in Tunisia was carried out for about 10 years by CITET and CWBI. Both landfills were managed by classical methodology i.e. disposal, compaction and, if any ... [more ▼]

The monitoring of two controlled landfills in Tunisia was carried out for about 10 years by CITET and CWBI. Both landfills were managed by classical methodology i.e. disposal, compaction and, if any, biogas and leachate extraction and treatment. One of them is located near Tunis and the other near Sousse with a warmer climate. They received more than 6,000 and 350 thousand cubic metre of MSW respectively from the two cities. Solid samples were collected by boring at different depths up to 18 m. They were analysed for dry weight and for total organic carbon, nitrogen and (hemi-) cellulose. The boreholes were equipped with 200 mm perforated PEHD tubes for further biogas and leachate sampling and analyses (COD, VFA, CH4 content, …) at different seasons. The results indicate an efficient mesophilic anaerobic digestion in both landfills. The high dry weight content (70 – 92%) of 13 solid samples collected in Sousse landfill contrasts however with the high leachate production in the Tunis landfill, filling about completely the majority of boreholes. The results of this monitoring confirm the trends formerly described about biological activity and environmental impact of landfills in Tunisia. Moreover a 200 L pilot-scale anaerobic digester was operated for about 3 years with solid wastes from Tunis landfill to assess the evolution of moisture content and organic matter. [less ▲]

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See detailANAEROBIC DIGESTION WITH BIOHYDROGEN PRODUCTION FROM ORGANIC WASTES : STATE-OF-THE ART
Hiligsmann, Serge ULg; Beckers, L.; Hamilton, C. et al

in Proceedings Sardinia 2013 (2013, October)

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. However, currently its production ... [more ▼]

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. However, currently its production relies mainly (i.e. 95%) on fossil fuels. The recent advances to produce biohydrogen from renewable sources such as biomass and particularly by fermentation of carbohydrate-rich substrates from agriculture and agro-industries appear promising. Such a process called “dark fermentation” enables both organic waste treatment and renewable energy production to be coupled. The soluble metabolites, mainly acetate and butyrate, contained in the spent medium of the dark fermentation bioreactor may be efficiently converted to methane in a second anaerobic digester treating other carbon sources. The paper reviews the state-of-the art on the challenges and prospective applications of dark fermentation as a first step of anaerobic digestion of municipal solid wastes to produce H2 and CH4. [less ▲]

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See detailComparative biochemical analysis during the anaerobic digestion of lignocellulosic biomass from six morphological parts of Williams Cavendish banana (Triploid Musa AAA group) plants
Kamdem, Irenee ULg; Hiligsmann, Serge ULg; Vanderghem, Caroline ULg et al

in World Journal of Microbiology & Biotechnology (2013)

We studied banana lignocellulosic biomass (BALICEBIOM) that is abandoned after fruit harvesting, and assessed its biochemical methane potential, because of its potential as an energy source. We monitored ... [more ▼]

We studied banana lignocellulosic biomass (BALICEBIOM) that is abandoned after fruit harvesting, and assessed its biochemical methane potential, because of its potential as an energy source. We monitored biogas production from six morphological parts (MPs) of the "Williams Cavendish" banana cultivar using a modified operating procedure (KOP) using KOH. Volatile fatty acid (VFA) production was measured using high performance liquid chromatography. The bulbs, leaf sheaths, petioles-midribs, leaf blades, rachis stems, and floral stalks gave total biogas production of 256, 205, 198, 126, 253, and 221 ml g-1 dry matter, respectively, and total biomethane production of 150, 141, 127, 98, 162, and 144 ml g-1, respectively. The biogas production rates and yields depended on the biochemical composition of the BALICEBIOM and the ability of anaerobic microbes to access fermentable substrates. There were no significant differences between the biogas analysis results produced using KOP and gas chromatography. Acetate was the major VFA in all the MP sample culture media. The bioconversion yields for each MP were below 50 %, showing that these substrates were not fully biodegraded after 188 days. The estimated electricity that could be produced from biogas combustion after fermenting all of the BALICEBIOM produced annually by the Cameroon Development Corporation-Del Monte plantations for 188 days is approximately 10.5 × 106 kW h (which would be worth 0.80-1.58 million euros in the current market). This bioenergy could serve the requirements of about 42,000 people in the region, although CH4 productivity could be improved. © 2013 Springer Science+Business Media Dordrecht. [less ▲]

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See detailDegradation of p-nitrophenol and bacteria with TiO2 xerogels sensitized in situ with tetra(4-carboxyphenyl)porphyrins
Tasseroul, Ludivine ULg; Lambert, Stéphanie ULg; Eskenazi, David ULg et al

in Journal of Photochemistry and Photobiology A : Chemistry (2013), 272

TiO2-based materials doped with porphyrins have been prepared using a sol-gel process. To stabilize the TiO2-dye interactions, free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl ... [more ▼]

TiO2-based materials doped with porphyrins have been prepared using a sol-gel process. To stabilize the TiO2-dye interactions, free metal tetra(4-carboxyphenyl)porphyrin and nickel tetra(4-carboxyphenyl) porphyrin were introduced in situ into the TiO2 matrix during the sol-gel process rather than by grafting. Samples were thoroughly characterized by TEM, X-ray diffraction, FT-IR, DR-UV/vis and their texture has been examined by nitrogen adsorption-desorption at 77 K. The low thermal treatment allows obtaining anatase-TiO2 particles with high specific surface area without porphyrin degradation. A significant improvement of the photoactivity under visible light of porphyrin doped-TiO2 xerogels was observed for p-nitrophenol and for bacterial degradation. © 2013 Elsevier B.V. All rights reserved. [less ▲]

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See detailImproving effect of metal and oxide nanoparticles encapsulated in porous silica on fermentative biohydrogen production by Clostridium butyricum.
Beckers, Laurent ULg; Hiligsmann, Serge ULg; Lambert, Stéphanie ULg et al

in Bioresource Technology (2013), 133C

This paper investigated the enhancement effect of nanometre-sized metallic (Pd, Ag and Cu) or metallic oxide (Fe(x)O(y)) nanoparticles on fermentative hydrogen production from glucose by a Clostridium ... [more ▼]

This paper investigated the enhancement effect of nanometre-sized metallic (Pd, Ag and Cu) or metallic oxide (Fe(x)O(y)) nanoparticles on fermentative hydrogen production from glucose by a Clostridium butyricum strain. These nanoparticles (NP) of about 2-3nm were encapsulated in porous silica (SiO(2)) and were added at very low concentration (10(-6)molL(-1)) in batch hydrogen production test. The cultures containing iron oxide NP produced 38% more hydrogen with a higher maximum H(2) production rate (HPR) of 58% than those without NP or with silica particles only. The iron oxide NP were used in a 2.5L sequencing-batch reactor and showed no significant effect on the yields (established at 2.2mol(hydrogen)mol(glucose)(-1)) but an improvement of the HPR (+113%, reaching a maximum HPR of 86mL(hydrogen)L(-1)h(-1)). These results suggest an improvement of the electron transfers trough some combinations between enzymatic activity and inorganic materials. [less ▲]

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See detailProduction de biohydrogène par fermentation anaérobie chimiotrophe de substrats carbohydratés
Hiligsmann, Serge ULg

Doctoral thesis (2012)

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. The recent advances to produce ... [more ▼]

Hydrogen (H2) is being considered as an ideal and clean energy carrier since the utilization of hydrogen, either via combustion or via fuel cells, results in pure water. The recent advances to produce biohydrogen from renewable sources such as biomass and particularly by fermentation of carbohydrate-rich substrates from agriculture and agro-industries appear promising. Such a process called “dark fermentation” enables both organic waste treatment and renewable energy production to be coupled. In the thesis different hydrogen-producing microorganisms were studied and some environmental parameters and bioreactors have been investigated in order to improve the hydrogen production yields and rates. The experimental results compared the hydrogen production yield of 19 different pure strains and sludges : facultative and strict anaerobic H2-producing strains along with anaerobic digester sludges thermally pre-treated (to enrich the microflora in high H2-producers) or not. Significant yields variations were recorded even between different strains of the same species (up to 20% of variation). The pure Clostridium butyricum (C. but.) strains achieved the highest yields i.e. up to 172 L H2 produced per kilogram of glucose consumed (1.38 mol H2 / mol glucose). Two efficient H2-producing strains (C. but. CWBI1009 and Citrobacter freundii CWBI952) were further studied in order to determine the optimum culture conditions for the production of hydrogen. A 2.3 L bioreactor was operated at 30 °C in batch and sequenced-batch mode using glucose and starch as substrates. For glucose the maximum yield (211 L H2 / kg or 1.7 mol H2 / mol glucose) was measured with the C. but. strain when the pH was maintained at 5.2. In sequenced-batch reactor a 35% increase in H2 yield was obtained with removal–addition of 40% of the culture medium at the beginning of each sequence. For operation in continuous mode, original bioreactors such as an anaerobic biodisc reactor (AnBDR) were designed to both fix biomass and enable rapid liquid to gas transfer of hydrogen produced since H2 partial pressure and H2 supersaturation are known as hardly affecting hydrogen production performances. The highest and stable H2 production rate (703 L H2 per hour and per m³ of liquid volume inside the bioreactor) and yield (302 L / kg glucose consumed i.e. 2.4 mol/mol) with the pure culture of C. but. CWBI1009 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 kg / m³.h. These results achieved with pure strains are relevant compared to the highest H2 yields and rates reported in the literature with mixed cultures and achieved in reactors, such as trickle bed bioreactors, with high gas transfer performances. Moreover, the soluble metabolites, mainly acetate and butyrate, contained in the spent medium of the dark fermentation bioreactor were efficiently converted to methane in a second anaerobic digester (20 L continuously stirred tank) with a methane yield of about 170 L/kg COD initially fed in the first stage. These results demonstrate that a two-step anaerobic digestion process may be carried out in two successive bioreactors, both with specific and optimized parameters, in order to generate separated biogas flows containing either H2 or CH4. In addition to the advantages related to both gaseous molecule properties, many technological improvements would be achieved by this way : better hydrolysis, higher process stability, etc. The general discussion highlights the central and relevant position of the 2-stage anaerobic digestion process in the panorama of technologies able to both treat raw or residual organic matter and to produce energy or energy vectors for stationary or mobile end-use. The technical, economical and environmental aspects have been considered. [less ▲]

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See detailInvestigating the factors for fermentative biohydrogen improvement: original bioreactors design and hydrogen partial pressure effect
Beckers, Laurent ULg; Hiligsmann, Serge ULg; Hamilton, Christopher ULg et al

in WHEC 2012, Toronto June 3rd - 7th (2012, June 05)

The anaerobic production of hydrogen from biomass offers the potential production of usable biogas from a variety of renewable resources. However, in order to produce hydrogen at high yields and ... [more ▼]

The anaerobic production of hydrogen from biomass offers the potential production of usable biogas from a variety of renewable resources. However, in order to produce hydrogen at high yields and production rates the biotechnological process needs to be further optimized and efficient bioreactors must be designed [1]. At the CWBI, a continuous horizontal rotating cylinder bioreactor has been designed and investigated to produce biohydrogen from glucose by the strain Clostridium butyricum [2] at good yields (1,9molH2•molglucose-1) and production rates (48,6mmolH2•Lmilieu-1.molhexose-1•h-1). This reactor has an internal volume of 2.3L and a small working volume (300ml) (fig.1). It enhances the hydrogen production rates (by about three times more than a completely stirred bioreactor) by partially immobilizing the bacteria on the porous support. Moreover, the rotating cylinder design enables efficient H2 gas transfer from the liquid phase increasing hydrogen yields by about 25% compared to a completely stirred bioreactor [3-4]. Other original bioreactors, such as a trickle bed, have been built with the same aim of lowering the hydrogen partial pressure and led to similar results. Our work shows the importance of a good liquid to gas transfers in the biohydrogen-producing reactors to reach higher performances. [less ▲]

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See detailThe MicroH2 project:an association of four laboratories to improve theknowledge on biohydrogen production precesses
Beckers, Laurent ULg; Calusinska, Magdalena ULg; Hamilton, Christopher ULg et al

Poster (2012, June 04)

This poster presents a collaborative research project (MicroH2) held at the University of Liège (Belgium) since 2007 (www.microh2.ulg.ac.be) and involving four different research groups. The project aims ... [more ▼]

This poster presents a collaborative research project (MicroH2) held at the University of Liège (Belgium) since 2007 (www.microh2.ulg.ac.be) and involving four different research groups. The project aims to develop a center of excellence in the fields of photo- and dark- biohydrogen production. Our studies contribute to improve the knowledge of the processes involved in the microbiological production of hydrogen, from a fundamental and practical point of view. Some results are highlighted here. The research concerning photofermentation focuses on the interactions between respiration, photosynthesis and H2-producing pathways in algal microorganisms, by using mitochondrial mutants and genetically modified strains with modified ability for hydrogen production [1-2]. To study the metabolism of the hydrogen production by anaerobic bacteria, pure cultures and defined consortia are used and their production of biogas and soluble metabolites is measured. Moreover, we have developed and optimized molecular tools, like quantitative RT-PCR and FISH, to monitor the variations of bacterial populations in novel bioreactors for hydrogen production [3-4]. We have also mined the complete genomes of Clostridium spp. for putative hydrogenase genes and found a large diversity of them [5]. [less ▲]

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See detailEffects of hydrogen partial pressure on fermentative biohydrogen production by a chemotropic Clostridium bacterium in a new horizontal rotating cylinder reactor
Beckers, Laurent ULg; Hiligsmann, Serge ULg; MAsset, Julien et al

in Energy Procedia (2012)

In order to produce fermentative biohydrogen at high yields and production rates, efficient bioreactors have to be designed. A new reactor called anaerobic biodisc reactor allowed the production of ... [more ▼]

In order to produce fermentative biohydrogen at high yields and production rates, efficient bioreactors have to be designed. A new reactor called anaerobic biodisc reactor allowed the production of biohydrogen from glucose with the selected Clostridium sp. strain at high yields (2.49 molH2•molglucose-1) and production rates (598 mlH2•medium-1•h-1). The bacteria were fixed on a rotating support enabling efficient gas transfer from the liquid to the phase. It allowed the metabolism of the bacteria to produce more hydrogen. Moreover, an increase of the total pressure 0.18 bar lowered the yields of 19.5% while a decrease of 0.11 bar increased the yields of 7%. Our work concludes on the importance of providing good liquid to gas transfers in the biohydrogen-producing reactors. [less ▲]

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