PGM2 overexpression improves anaerobic galactose fermentation in Saccharomyces cerevisiae

Microbial Cell Factories

Research

Marie F Gorwa-Grauslund¹  Bärbel Hahn-Hägerdal¹  Rosa Garcia Sanchez¹ 

[1] Department of Applied Microbiology, Lund University, P.O. Box 124, SE-22100, Lund, Sweden;

关键词: Galactose;    Specific Growth Rate;    Maximum Specific Growth Rate;    Anaerobic Fermentation;    Multicopy Plasmid;   

DOI  :  10.1186/1475-2859-9-40

 received in 2010-03-04, accepted in 2010-05-27,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundIn Saccharomyces cerevisiae galactose is initially metabolized through the Leloir pathway after which glucose 6-phosphate enters glycolysis. Galactose is controlled both by glucose repression and by galactose induction. The gene PGM2 encodes the last enzyme of the Leloir pathway, phosphoglucomutase 2 (Pgm2p), which catalyses the reversible conversion of glucose 1-phosphate to glucose 6-phosphate. Overexpression of PGM2 has previously been shown to enhance aerobic growth of S. cerevisiae in galactose medium.ResultsIn the present study we show that overexpression of PGM2 under control of the HXT7' promoter from an integrative plasmid increased the PGM activity 5 to 6 times, which significantly reduced the lag phase of glucose-pregrown cells in an anaerobic galactose culture. PGM2 overexpression also increased the anaerobic specific growth rate whereas ethanol production was less influenced. When PGM2 was overexpressed from a multicopy plasmid instead, the PGM activity increased almost 32 times. However, this increase of PGM activity did not further improve aerobic galactose fermentation as compared to the strain carrying PGM2 on the integrative plasmid.ConclusionPGM2 overexpression in S. cerevisiae from an integrative plasmid is sufficient to reduce the lag phase and to enhance the growth rate in anaerobic galactose fermentation, which results in an overall decrease in fermentation duration. This observation is of particular importance for the future development of stable industrial strains with enhanced PGM activity.

【 授权许可】

Unknown   
© Sanchez et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.