PubAg

Main content area

Xylitol production by recombinant Saccharomyces cerevisiae expressing the Pichia stipitis and Candida shehatae XYL1 genes

Author:
Govinden, R., Pillay, B., Van Zyl, W.H., Pillay, D.
Source:
Applied microbiology and biotechnology 2001 v.55 no.1 pp. 76-80
ISSN:
0175-7598
Subject:
Candida shehatae, Saccharomyces cerevisiae, Scheffersomyces stipitis, electroporation, galactose, genes, glucose, maltose, promoter regions, xylitol, xylose
Abstract:
The xylose reductase gene (XYL1) was isolated from Pichia stipitis and Candida shehatae, cloned into YEp-based vectors under the control of ADH2 and PGK1 promoter/terminator cassettes and introduced into Saccharomyces cerevisiae Y294 by electroporation. Shake-flask fermenatations were carried out with 5% xylose and 1% galactose, glucose or maltose as co-substrates. Xylose uptake was similar in both the recombinant strains when different co-substrates were used and slowed once the co-substrate was depleted. The recombinant strains converted xylose to xylitol with yields approaching the theoretical maxima. Xylitol production was most rapid when the co-substrate was still present. Approximately 50% of the xylose was not metabolized due to the depletion of the co-substrate.
Agid:
1952714