TRANSFORMED SACCHAROMYCES CEREVISIAE ENGINEERED FOR XYLOSE UTILIZATION

摘要

Recombinant Saccharomyces cerevisiae produced by transformation with heterologous polynucleotide sequences coding for xylulokinase (XKS) from Yersinia pestis and xylose isomerase (XI) are capable of xylose utilization. The transformants express these heterologous polynucleotides at a sufficient functional level to grow aerobically on xylose as the sole carbon source. Further transformation of the recombinant yeasts to overexpress one or more of the S cerevisiae genes PIP2, IMG2, MAK5, VPS9, COXlO, ALEl, CDC7, and MMS4, permits the yeast to grow anaerobically on xylose as the sole carbon source. When grown under anaerobic conditions on a culture medium comprising both glucose and xylose, the transformed yeast exhibit increased ethanol productivity, with the yeast growing on the xylose to increase their biomass and fermenting the glucose to ethanol.