Control of the rumen fermentation needs a basic knowledge of the rumen microbes. This short paper provides a few examples of work on the types and metabolic characteristics of the organisms and the influence of external conditions on their growth and metabolism. The term ‘fermentation patterns’ in the rumen is generally understood to denote principally the proportions of three volatile fatty ac...

12 Yeast has long been considered the microorganism of choice for second generation bioethanol 13 production due to its fermentative capacity and ethanol tolerance. However, tolerance towards 14 inhibitors derived from lignocellulosic materials is still an issue. Flocculating yeast strains often 15 perform relatively well in inhibitory media, but inhibitor tolerance has never been clearly linke...

Arginine metabolism in Enterococcus faecium sp. GR7 was enhanced via arginine deiminase pathway. Process parameters including fermentation media and environmental conditions were optimized using independent experiments and response surface methodology (central composite design). Fermentation media (EAPM) were optimized using independent experiments which resulted in 4-fold increase in arginine ...

The studies on the alcoholic fermentation with immobilized S. cerevisiae cells on alginate using a bioreactor with stirred beds of biocatalysts indicated that the diffusion inside the biocatalyst particles attenuates or avoids the inhibitory effects, preserving the microbial activity. Using a mathematical model adequate for ethanol formation in heterogeneous systems the kinetic parameters V, KI...

The possible use of cotton waste as a carbohydrate source of citric acid production by Aspergillus niger was examined. No citric acid was produced when A. niger was grown on cotton waste as a sole carbon source. In two-stage fermentations, however, mycelium obtained from surface cultures in cotton waste medium yielded more citric acid when transferred to sucrose-containing media than when direc...

Fermentation is a microbial biotechnology whereby natural renewable substrates are converted to value-added products such as enzymes, organic acids, alcohols, polymers, and more. Fermentation end-products such as ethanol and lactic acid are proton sinks, whereby NADH is recycled to NAD, which allows the cell to continue producing energy via glycolysis by substrate-level phosphorylation. Thus, m...

BACKGROUND Hyaluronic acid is one of the biopolymers most commonly used by the pharmaceutical industry. Thus, there is an increasing number of recent works that deal with the production of microbial hyaluronic acid. Different properties and characteristics of the fermentation process have been extensively optimised; however, new carbon and protein sources obtained from by-products or cheap subs...