Background Molecular hydrogen (H2) is an attractive future energy carrier to replace fossil fuels. Biologically and sustainably produced H2 could contribute significantly to the future energy mix. However, biological H2 production methods are faced with multiple barriers including substrate cost, low production rates, and low yields. The C1 compound formate is a promising substrate for biologic...

the objective of this meta-analysis was to compare effects of chemical methanogenic inhibitors on fermentation parameters in ruminal batch cultures. nine published in vitro studies including 26 treatment means in which 2-bromoethane sulfonate, bromochloromethane and 9,10-anthraquinone were used as methanogens inhibitor compared in amount of ch4, h2, total volatile fatty acid, actate, propionate...

The [FeFe]-hydrogenase CpHydA from Clostridium perfringens was immobilized by adsorption on anatase TiO2 electrodes for clean hydrogen production. The immobilized enzyme proved to perform direct electron transfer to and from the electrode surface and catalyses both H2 oxidation (H2 uptake) and H2 production (H2 evolution) with a current density for H2 evolution of about 2 mA cm(-1). The TiO2/Cp...

BACKGROUND Biological fermentation routes can provide an environmentally friendly way of producing H2 since they use renewable biomass as feedstock and proceed under ambient temperature and pressure. In particular, photo-fermentation has superior properties in terms of achieving high H2 yield through complete degradation of substrates. However, long-term H2 production data with stable performan...

BACKGROUND Fermentative hydrogen (H2) production suffers from low carbon-to-H2 yield, to which problem, co-production of ethanol and H2 has been proposed as a solution. For improved co-production of H2 and ethanol, we developed Escherichia coli BW25113 ΔhycA ΔhyaAB ΔhybBC ΔldhA ΔfrdAB Δpta-ackA ΔpfkA (SH8*) and overexpressed Zwf and Gnd, the key enzymes in the pentose-phosphate (PP) pathway (SH...

Turning organic wastes into hydrogen (H2) by using anaerobic fennentative technology is an ideal concept because this can accomplish both waste treatment and energy recovery objectives. However, H2 production using anaerobic fennentative approaches faces a fundamental limitation of poor H2 production yield (i.e. < 4 mol H2 per mol of hexose). This article gives an overview on the limitations of...

In Chlamydomonas reinhardtii cells, H2 photoproduction can be induced in conditions of sulfur deprivation in the presence of acetate. The decrease in photosystem II (PSII) activity induced by sulfur deprivation leads to anoxia, respiration becoming higher than photosynthesis, thereby allowing H2 production. Two different electron transfer pathways, one PSII dependent and the other PSII independ...

Hydrogen sulfide (H2 S) and nitric oxide (NO) are major gasotransmitters produced in endothelial cells (ECs), contributing to the regulation of vascular contractility and structural integrity. Their interaction at different levels would have a profound impact on angiogenesis. Here, we showed that H2 S and NO stimulated the formation of new microvessels. Incubation of human umbilical vein endoth...

The production of methane (CH4) or hydrogen (H2) from renewable biomass by microorganisms growing anaerobically has the potential for contribution to independence from fossil fuels. Anaerobes function in Nature by converting biomass to CH4 through food chains comprised of fermentative and acetogenic species, which decompose the complex biomass to H2, formate and acetate that are further metabol...

Cyanobacteria are considered good models for biohydrogen production because they are relatively simple organisms with a demonstrable ability to generate H2 under certain physiological conditions. However, most produce only little H2, revert readily to H2 consumption, and suffer from hydrogenase sensitivity to O2. Strains of the cyanobacteria Lyngbya aestuarii and Microcoleus chthonoplastes obta...