Investigation of the impact of MIG1 and MIG2 on the physiology of Saccharomyces cerevisiae

The gene functions of MIG1 and MIG2 are well known for their role in glucos e control in Saccharomyces cerevisiae. A prototrophic mig1 disruptant (T468 ) and mig1mig2 double disruptant (T475) as well as their congenic wild-type strain (CEN.PK 113-7D) were analysed for changes in their peripheral metab olism (batch cultivations on sugar mixtures) and central metabolism (batch and continuous cultivations as well as acceleratostats). Sucrose metabolism was alleviated of glucose control in the mig1 disruptant, and even more so in the mig1mig2 disruptant compared with their wild-type strain. The lag p hase in a batch cultivation grown on a glucose-galactose mixture was reduce d by 50% in either disruptant, i.e. additional disruption of MIG2 in a mig1 background did not further alleviate galactose metabolism from glucose con trol. In contrast, both disruptants exhibited a more stringent glucose cont rol of maltose metabolism compared with the wild-type strain, Growing on gl ucose, the mig1mig2 double disruptant exhibited a 12% higher specific growt h rate than the wild-type strain, as well as a significantly higher respira tory capacity. (C) 1999 Elsevier Science B.V. All rights reserved.