Aspergillus oryzae glucoamylases encoded by glaA and glaB, and Rhizopus oryzae glucoamylase, were displayed on the cell surface of sake yeast Saccharomyces cerevisiae GRI-117-UK and laboratory yeast S. cerevisiae MT8-1. Among constructed transformants, GRI-117-UK/pUDGAA, displaying glaA glucoamylase, produced the most ethanol from liquefied starch, although MT8-1/pUDGAR, displaying R. oryzae gl...

The Thermus thermophilus xylA gene encoding xylose (glucose) isomerase was cloned and expressed in Saccharomyces cerevisiae under the control of the yeast PGK1 promoter. The recombinant xylose isomerase showed the highest activity at 85 degrees C with a specific activity of 1.0 U mg-1. A new functional metabolic pathway in S. cerevisiae with ethanol formation during oxygen-limited xylose fermen...

BACKGROUND Pretreatment is an important step in the production of ethanol from lignocellulosic material. Using acetic acid together with steam pretreatment allows the positive effects of an acid catalyst to be retained, while avoiding the negative environmental effects associated with sulphuric acid. Acetic acid is also formed during the pretreatment and hydrolysis of hemicellulose, and is a kn...

Culturing haploid strains of Saccharomyces cerevisiae in liquid minimal medium with 2% ethanol and 2% leucine resulted in the formation of long anucleate pseudohyphae. This occurred only with the combination of ethanol as carbon source and leucine as nitrogen source and was independent of mating type. The transition to a pseudohyphal form observed under these conditions appears to be irreversib...

Production of bioethanol and bioelectricity is a promising approach through microbial electrochemical technology. Sugars are metabolized by yeast to produces ethanol, CO2, energy. Surplus electrons produced during the fermentation can be transferred circuit generate electricity in fuel cell (MFC). In present study, membrane-less single-chambered was developed for simultaneous production bioelec...

Glucose was used as a cosubstrate under anaerobic conditions in the conversion of xylose to xylitol by a recombinant Saccharomyces cerevisiae strain expressing the xyl1 gene. Glucose was metabolized mainly through glycolysis, with carbon dioxide, acetate, and ethanol as end products and with reduction equivalents generated in the glyceraldehyde-3-phosphate dehydrogenase and acetaldehyde dehydro...

To utilize starch and protein contained in microalgae as carbon and nitrogen sources for ethanol production, an extraction method, i.e. ultrasonic treatment using a homogenizer, and simultaneous saccharification and fermentation (SSF) of extracted microalgae solution were studied using Chlamydomonas fasciata Ettl 437. 30 min of ultrasonic treatment gave the maximum extraction ratio of starch co...

Glucose was converted to ethanol by calcium-alginate-entrapped Saccharomyces cerevisiae NRRL Y-2034 cells that were 24, 48, 72, and 96 h old in continuous-flow and static repeated-batch fermentors. In general, older yeast cells were more efficient than younger ones. In most cases, the continuous fermentations were better than the static ones in producing maximum ethanol yields (5.11 g/10 g of g...

Viable Saccharomyces cerevisiae suspended in medium containing growth-inhibiting concentrations of ethanol produce a metabolite that relieves growth inhibition. This autoconditioning of the medium by yeasts is due to the formation of small amounts (0.01%, vol/vol) of acetaldehyde. The effect is duplicated precisely in fresh medium by the addition of acetaldehyde. Acetaldehyde does not increase ...

The Saccharomyces cerevisiae wine yeast strains 71B-1122 and K1-V1116 were used to derive strains that could tolerate and produce higher ethanol yields. Respiratory-deficient mutants resistant to 500 microg/mL lycorine were isolated. Two mutants, 71B-1122 YEBr L3 and K1-V1116 YEBr L4, were shown to achieve about 10% and 18% improvement in their glucose-to-ethanol conversion efficiency compared ...