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The lag phase of Saccharomyces cerevisiae subjected to a step increase in temperature or ethanol concentration was reduced by as much as 60% when acetaldehyde was added to the medium at concentrations less than 0.1 g/L. Maximum specific growth rates were also substantially increased. Even greater proportional reductions in lag time due to acetaldehyde(More)
This study investigated the biodegradation of high-molecular-weight polycyclic aromatic hydrocarbons (PAHs) in liquid media and soil by bacteria (Stenotrophomonas maltophilia VUN 10,010 and bacterial consortium VUN 10,009) and a fungus (Penicillium janthinellum VUO 10, 201) that were isolated from separate creosote- and manufactured-gas plant-contaminated(More)
When inoculated at high cell densities, three strains of Pseudomonas cepacia degraded the polycyclic aromatic hydrocarbons (PAHs) benzo[a]pyrene, dibenz[a,h]anthracene and coronene as sole carbon and energy sources. After 63 days incubation, there was a 20 to 30% decrease in the concentration of benzo[a]pyrene and dibenz[a,h]anthracene and a 65 to 70%(More)
Saccharomyces cerevisiae is traditionally used for alcoholic beverage and bioethanol production; however, its performance during fermentation is compromised by the impact of ethanol accumulation on cell vitality. This article reviews studies into the molecular basis of the ethanol stress response and ethanol tolerance of S. cerevisiae; such knowledge can(More)
Two distinct forms of phosphoglucomutase were found in Lactococcus lactis subsp. lactis, strains 19435 and 65.1, growing on maltose: beta-phosphoglucomutase (beta-PGM), which catalyzes the reversible conversion of beta-glucose 1-phosphate to glucose 6-phosphate in the maltose catabolism, and alpha-phosphoglucomutase (alpha-PGM). beta-PGM was purified to(More)
Maltose metabolism in Lactococcus lactis involves the conversion of beta-glucose 1-phosphate to glucose 6-phosphate, a reaction which is reversibly catalysed by a maltose-inducible and glucose-repressible beta-phosphoglucomutase (beta-PGM). The gene encoding beta-PGM (pgmB) was cloned from a genomic library of L. lactis using antibodies. The nucleotide(More)
Acetaldehyde at above about 0.3 g/l inhibited yeast growth, suggesting that it may contribute to product inhibition in alcohol fermentations when present at high concentrations intracellularly. The toxic effects of acetaldehyde and ethanol were not mutually reinforcing, acetaldehyde appearing to alleviate slightly the effects of ethanol. In support of this,(More)
In the simultaneous saccharification and fermentation to ethanol of 100 g l(-1) microcrystalline cellulose, the cellobiose-fermenting recombinant Klebsiella oxytoca P2 outperformed a range of cellobiose-fermenting yeasts used in earlier work, despite producing less ethanol than reported earlier for this organism under similar conditions. The time taken by(More)
Differing claims regarding the stability of the recombinant ethanologen E. coli KO11 are addressed here in batch and chemostat culture. In repeat batch culture, the organism was stable on glucose, mannose, xylose and galactose for at least three serial transfers, even in the absence of a selective antibiotic. Chemostat cultures on glucose were remarkably(More)
The ability of Stenotrophomonas maltophilia strain VUN 10,003 to degrade and detoxify high molecular weight polycyclic aromatic hydrocarbons (PAHs) was evaluated in a basal liquid medium. Using high cell density inocula of strain VUN 10,003, the concentration of pyrene, fluoranthene, benz[a]anthracene, benzo[a]pyrene, dibenz[a, h]anthracene and coronene(More)