Biotechnology Progress 2010-01-01

Accelerating glycolytic flux of Torulopsis glabrata CCTCC M202019 at high oxidoreduction potential created using potassium ferricyanide.

Yi Qin, Li-Ming Liu, Chang-Hao Li, Sha Xu, Jian Chen

Index: Biotechnol. Prog. 26(6) , 1551-7, (2010)

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Abstract

This study aimed to increase the glycolytic flux of the multivitamin auxotrophic yeast Torulopsis glabrata by redirecting NADH oxidation from oxidative phosphorylation to membrane-bound ferric reductase. We added potassium ferricyanide as electron acceptor to T. glabrata culture broth at 20% dissolved oxygen (DO) concentration, which resulted in: (1) decreases in the NADH content, NADH/NAD(+) ratio, and ATP level of 45.3%, 60.3%, and 15.2%, respectively; (2) high activities of the key glycolytic enzymes hexokinase, phosphofructokinase, and pyruvate kinase, as well as high expression levels of the genes encoding these enzymes; and (3) increases in the specific glucose consumption rate and pyruvate yield of T. glabrata was by 45.5% and 23.1%, respectively. Our results showed that membrane-bound ferric reductase offers an alternative and efficient NADH oxidation pathway at lower DO concentration, which increases the glycolytic flux of T. glabrata.Copyright © 2010 American Institute of Chemical Engineers (AIChE).