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Improvement of xylose fermentation is of great importance to the fuel ethanol industry. The nonconventional thermotolerant yeast Hansenula polymorpha naturally ferments xylose to ethanol at high temperatures (48-50 degrees C). Introduction of a mutation that impairs ethanol reutilization in H. polymorpha led to an increase in ethanol yield from xylose. The(More)
This paper reports on the experimental data supporting an essential role of extra-cellular reduction in chromate detoxification by baker’s and non-conventional yeasts. A decrease of chromate content in the yeast culture coincides with an increase of Cr(III) content in extra-cellular liquid. At these conditions, cell-bound chromium level was insignificant(More)
Considered are our own data and those found in literature on the properties of yeast mutants impaired in their ability to utilize methanol as sole carbon and energy source; hypotheses about the role of alcohol oxidase and citrate synthase in biogenesis of peroxisomes are proposed. It has been proved that formaldehyde reductase participates in the control of(More)
Nonmethylotrophic (Candida maltosa and Saccharomyces cerevisiae) and methylotrophic (Hansenula polymorpha) yeast cells acidified their incubation media in the presence of formaldehyde. This was associated with the release of formate. We studied the formaldehyde-dependent production of formic acid and the enzymatic properties of these strains grown on media(More)
A recombinant yeast clone, a derivative of the recipient Hansenula polymorpha strain NCYC 495, was chosen as an NAD and glutathione-dependent formaldehyde dehydrogenase overproducer. Optimal cultivation conditions for the highest yield of enzyme were established. A simple scheme for the isolation of formaldehyde dehydrogenase from the recombinant strain was(More)
The paper describes the selection of chromate-resistant mutants of the yeast Pichia guilliermondii with a higher chromate-reducing activity and reports the EPR-study of Cr(V)-generation in the extra-cellular medium during the reduction of chromate by the yeast culture. It is shown that the reduction of chromate to Cr(III) species runs through the(More)
Aliphatic amines, including methylamine, are air-pollutants, due to their intensive use in industry and the natural degradation of proteins, amino acids, and other nitrogen-containing compounds in biological samples. It is necessary to develop systems for removal of methylamine from the air, since airborne methylamine has a negative effect on human health.(More)
A d-lactate-selective biosensor has been developed using cells' debris of recombinant thermotolerant methylotrophic yeast Hansenula polymorpha, overproducing d-lactate: cytochrome c-oxidoreductase (EC 1.1.2.4, d-lactate dehydrogenase (cytochrome), DlDH). The H. polymorpha DlDH-producer was constructed in two steps. First, the gene CYB2 was deleted on the(More)
Mutants of the methylotrophic yeast Hansenula polymorpha deficient in NAD-dependent formaldehyde or formate dehydrogenases have been isolated. They were more sensitive for exogenous methanol but retained the ability for methylotrophic growth. In the medium with methanol the growth yields of the mutant 356–83 deficient in formaldehyde dehydrogenase and of(More)