The genetic basis of organisms' adaptation to different environments is a central issue of molecular evolution. The budding yeast Saccharomyces cerevisiae and its relatives predominantly ferment glucose into ethanol even in the presence of oxygen. This was suggested to be an adaptation to glucose-rich habitats, but the underlying genetic basis of the evolution of aerobic fermentation remains un...

The amino acid pool of yeast cells, Saccharomyces cerevisiae, incubated with galactose remains at a constant level for 100 minutes. This is 30 minutes beyond the time at which the oxidative phase of the induced-enzyme formation begins. Washed yeast cells, the pools of which have been depleted 60 per cent by incubation with glucose, do not replenish their pools as do washed cells incubated witho...

BACKGROUND For economical bioethanol production from lignocellulosic materials, the major technical challenges to lower the production cost are as follows: (1) The microorganism should use efficiently all glucose and xylose in the lignocellulose hydrolysate. (2) The microorganism should have high tolerance to the inhibitors present in the lignocellulose hydrolysate. The aim of the present work ...

mycophenolic acid is a secondary extracellular metabolite of penicillium strains with numerous pharmaceutical properties such as antibiotic and immunosuppressive uses. the aim of this work is the survey of the effect of phenylglyoxal and n-ethylmaleimide concentration in culture medium on mycophenolic acid production by penicillium brevi-compactum atcc16024 was investigated. batch submerged fer...

glycerol is a promising feedstock for microbial cultivation and production of 1,3 propanediol (1,3 pdo). here we report a newly isolated bacterial strain ba11 from soil, capable of fermenting glycerol to 1,3 pdo, and has been identified to be a strain of klebsiella pneumoniae. strain ba11 was fast growing showing peak 1,3 pdo production in 6 h of cultivation with productivity of 1.2 g/l-h witho...

Lactococcus lactis is a widely used food bacterium mainly characterized for its fermentation metabolism. However, this species undergoes a metabolic shift to respiration when heme is added to an aerobic medium. Respiration results in markedly improved biomass and survival compared to fermentation. Whole-genome microarrays were used to assess changes in L. lactis expression under aerobic and res...

OBJECTIVE This study investigated the association of yeast species with improved aerobic stability of total mixed ration (TMR) silages with prolonged ensiling, and clarified the characteristics of yeast species and their role during aerobic deterioration. METHODS Whole crop corn (WCC) silages and TMR silages formulated with WCC were ensiled for 7, 14, 28, and 56 d and used for an aerobic stab...

The Crabtree positive yeasts, such as Saccharomyces cerevisiae, prefer fermentation to respiration, even under fully aerobic conditions. The selective pressures that drove the evolution of this trait remain controversial because of the low ATP yield of fermentation compared to respiration. Here we propagate experimental populations of the weak-Crabtree yeast Lachancea kluyveri, in competitive c...

Pseudomonas sp. RZS1 was isolated from distillery effluent and identified based on phenotypic characters and 16s rRNA sequencing. It accumulated optimum amount (703.79 microg/mg of biomass) of poly-beta-hydroxybutyrate (PHB) under aerobic process of fermentation and 75 microg/mg of biomass under the anaerobic process of fermentation. Aerobic fermentation yielded 9.3-fold more PHB than semi-aero...

The main aim of this work is the development of mathematical models of aerobic batch fermentations for its use in estimation and control algorithms. Most batch fermentation models are empirical and simple, and do not provide interrelationships between state variables and measurements. In this work such interrelationships are obtained from mass and energy balances of the fermentation components....