Kurylenko O. Metabolic engineering for improvement of high-temperature xylose alcoholic fermentation in yeast Ogataea polymorpha

Aim of the work: to develop metabolic engineering approaches for construction of recombinant O. polymorpha strains with improved high-temperature xylose alcoholic fermentation. Object of the research: ethanol production during alcoholic fermentation and regulation of this process in the thermotolerant yeast О. polymorpha. Methods: micribiological, genetic and biochemical. The efficiency of ethanol production from xylose in yeast О. polymorpha was improved by metabolic engineering and classical selection approaches. Thew role of cytosolic and peroxisomal enzymes of pentose phosphate pathway as well as Cat8 transcriptional activator in xylose alcoholic fermentation was revealed during the fulfillment of the work. The method of positive selection with 3-bromopyruvate was used for the first time for selection of yeast strains with tmproved ethanol production from xylose. As a result of this work the limiting steps in the pathway of xylose conversion to ethanol were revealed in xylose-fermenting yeast О. polymorpha.