Ensiling is a method of preserving a moist crop. A moist crop can support the growth of a wide range of microorganisms, most of which will degrade the nutrient value to livestock. However, ensiling generally controls microbial activity by a combination of an anaerobic environment and a natural fermentation of sugars by lactic acid bacteria on the crop. This fermentation and the resulting low pH...

BACKGROUND Propionate is widely used as an important preservative and important chemical intermediate for synthesis of cellulose fibers, herbicides, perfumes and pharmaceuticals. Biosynthetic propionate has mainly been produced by Propionibacterium, which has various limitations for industrial application. RESULTS In this study, we engineered E. coli by combining reduced TCA cycle with the na...

In the last decades the increasing energy requirements along with the need to face the consequences of climate change have driven the search for renewable energy sources, in order to replace as much as possible the use of fossil fuels. In this context biomass has generated great interest as it can be converted into energy via several routes, including fermentation and anaerobic digestion. The f...

BACKGROUND Cellobiose and xylose co-fermentation holds promise for efficiently producing biofuels from plant biomass. Cellobiose phosphorylase (CBP), an intracellular enzyme generally found in anaerobic bacteria, cleaves cellobiose to glucose and glucose-1-phosphate, providing energetic advantages under the anaerobic conditions required for large-scale biofuel production. However, the efficienc...

Under anaerobic conditions, the yeast Saccharomyces bulderi rapidly ferments -gluconolactone to ethanol and carbon dioxide. We propose that a novel pathway for -gluconolactone fermentation operates in this yeast. In this pathway, -gluconolactone is first reduced to glucose via an NADPH-dependent glucose dehydrogenase (EC 1.1.1.47). After phosphorylation, half of the glucose is metabolized via t...

Members of the genus Arthrobacter are usually regarded as obligate aerobic bacteria. The anaerobic growth and energy metabolism of two Arthrobacter species were investigated. Arthrobacter globiformis utilized both nitrate ammonification and lactate, acetate and ethanol producing fermentation processes for anaerobic growth. Only nitrate supported anaerobic growth of Arthrobacter nicotianae. Anae...

Fermentation of sugars for hydrogen production has received increasing interest as a “green fuel” process. Models describing products formation from sugar fermentation has been the focus, applied to generalize anaerobic digestion models. Such models have therefore been in continuous development. Beginning from fixed stoichiometry values as in ADM1 [1] (the most common platform in anaerobic dige...

Acetobacterium bakii DSM 8239 is an anaerobic, psychrophilic, and chemolithoautotrophic bacterium that is a potential platform for producing commodity chemicals from syngas fermentation. We report here the draft genome sequence of A. bakii DSM 8239 (4.14 Mb) to elucidate its physiological and metabolic properties related to syngas fermentation.

Clostridium aceticum DSM 1496 is a Gram-negative anaerobic chemolithoautotrophic acetogenic bacterium that is capable of producing commodity chemicals from syngas fermentation. In this study, we report the draft genome sequence of the C. aceticum DSM 1496 strain (4.16 Mb) to elucidate the syngas fermentation metabolic pathway.

The anaerobic growth of the yeast Saccharomyces cerevisiae normally requires the addition of molecular oxygen, which is used to synthesize sterols and unsaturated fatty acids (UFAs). A single oxygen pulse can stimulate enological fermentation, but the biochemical pathways involved in this phenomenon remain to be elucidated. We showed that the addition of oxygen (0.3 to 1.5 mg/g [dry mass] of ye...