Kefir is a putatively health-promoting dairy beverage that is produced when a kefir grain, consisting of a consortium of microorganisms, is added to milk to initiate a natural fermentation. Here, a detailed analysis was carried out to determine how the microbial population, gene content, and flavor of three kefirs from distinct geographic locations change over the course of 24-h fermentations. ...

This study was carried out to investigate the potential fermentation properties of juçara pulp, using pH-controlled anaerobic batch cultures reflective of the distal region of the human large intestine. Effects upon major groups of the microbiota were monitored over 24h incubations by fluorescence in situ hybridisation (FISH). Short-chain fatty acids (SCFA) were measured by HPLC. Phenolic compo...

The influence of the microbial-mammalian metabolic axis is becoming increasingly important for human health. Bacterial fermentation of carbohydrates (CHOs) and proteins produces short-chain fatty acids (SCFA) and a range of other metabolites including those from aromatic amino acid (AAA) fermentation. SCFA influence host health as energy sources and via multiple signalling mechanisms. Bacterial...

Fermentation of renewable feedstocks by microbes to produce sustainable fuels and chemicals has the potential to replace petrochemical-based production. For example, carboxylic acids produced by microbial fermentation can be used to generate primary building blocks of industrial chemicals by either enzymatic or chemical catalysis. In order to achieve the titer, yield and productivity values req...

Biogas production technologies commonly involve the use of natural anaerobic consortia of microbes. The objective of this study was to elucidate the importance of hydrogen in this complex microbial food chain. Novel laboratory biogas reactor prototypes were designed and constructed. The fates of pure hydrogen-producing cultures of Caldicellulosiruptor saccharolyticus and Enterobacter cloacae we...

Microbial biotransformation is a great model system to produce drugs and biologically active compounds. In this study, we elucidated the fermentation and production of an anti-cancer agent from a microbial process for regiospecific hydroxylation of resveratrol. Among the strains examined, a potent strain showed high regiospecific hydroxylation activity to produce piceatannol. In a 5 L (w/v 3 L)...

In the course of screening for unique microbial products with pharmacological activity, we have isolated two metabolites from the fermentation filtrate of an unidentified Streptomyces sp. SCC 2313, which exhibited an affinity for muscarinic receptors. The assay directed separation of the active ingredients provided two compounds1 and 2. Based on physico-chemical characteristics, we have elucida...

A novel microbial approach to the production of enantiomerically enriched and pure aroma compounds based on kinetic resolution via solid-state fermentation is proposed. Twenty-five filamentous fungi were screened for lipase activity and enantioselective hydrolysis of a volatile racemic ester (1-phenylethyl acetate (1)) and several racemic lactones (trans and cis whisky lactones (4, 5), γ-decala...

Xylitol is an extracellular sugar alcohol produced by the biological conversion of xylose through the fermentation process. The present study investigates the reaction kinetics of xylitol fermentation by considering the effect of substrate and product concentration on the microbial growth rate. A 3.5-L batch fermentation produced xylitol at different xylose concentrations and agitation speeds. ...

The growing public concerns over chemical residues in animal-derived foods and threats of antibiotic-resistant bacteria have renewed interest in exploring safer alternatives to chemical feed additives in ruminant livestock. Various bioactive phytochemicals including saponins appear to be potential 'natural' alternatives to 'chemical' additives in modulating rumen fermentation favourably and ani...