Species of genetically modified yeast, and fermentation processes that employ genetically modified yeasts

摘要

A genetically modified yeast cell that overexpresses a functional xylulokinase and has a functional exogenous xylose isomerase gene integrated into its genome, in which the exogenous xylose isomerase gene is at least 90% homologous with SEQ ID NO: 162 or encodes a Xylose isomerase enzyme that is at least 60% homologous with SEQ ID NO: 163 and has an identity score less than 95% compared to SEQ ID NO: 59 and a positive score less than 97% compared to SEQ ID NO: 59, and the xylose isomerase gene is operably linked to promoter and terminator sequences that are functional in the yeast cell, and the modified yeast cell further exhibits a deletion or alteration of a native gene that produces an enzyme that catalyzes the conversion of xylose in xylitol.