[Cloning of a gene encoding cytoplasmic glycerol-3-phosphate dehydrogenase from Candida glycerolgenesis]

The response of the yeast Saccharomyces cerevisiae to osmotic stress is to synthesis and accumulate the glycerol in order to increase the internal osmolarity and this response is controlled by the high-osmolarity glycerol (HOG) response pathway, whose important target gene is GPD1. The increase of the activity of glycerol-3-phosphate dehydrogenase by over-expression of GPD1 gene can increase the glycerol yield greatly. In this study, a gene encoding cytoplasmic glycerol-3-phosphate dehydrogenase of Candida glycerolgenesis was cloned out by inserting Sau3AI-generated chromosomal DNA fragments into the BamHI site of a yeast-E. coli shuttle vector, YEp51. Fifteen transformants were isolated on a supplemented minimal medium containing 50 g/L of sodium chloride from the constructed C. glycerol-genesis genomic library by using genetic complement approach. The recombinant plasmid, YEp0601, from transformant 0601, possessed the genetic markers of YEp51 and was able to restore the osmotolerance of S. cerevisiae 642(gpd1 delta, gpd2 delta). These indicated that a gene coding for cytoplasmic glycerol-3-phosphate dehydrogenase of C. glycerolgenesis was successfully cloned out.