Abstract:

This work studied effects of knockout of gene CYS3 on methionol anabolism in Saccharomyces cerevisiae(S. cerevisiae). A fragment of gene CYS3 and the resistance marker gene Zeocin were cloned and a construct of knockoutof gene CYS3 CYS3Δ:Zeocin was built. Using chemical lithium acetate method, the component（CYS3Δ:Zeocin）wasintroduced into S. cerevisiae S288C and an engineering bacterium with the knockout of gene CYS3 was obtained. Theresults showed that methionol yields of S. cerevisiae C3 and S. cerevisiae S288C were 0.60 g/L and 0.94 g/L in shake flaskfermentation at 120 h, respectively. Compared to that of S. cerevisiae S288C, the methionol yield of S. cerevisiae C3 wasdecreased by 36.2%. These results suggested that knockout of gene CYS3 had a great influence on methionol anabolism,which appeared to play a negatively regulatory role.

Key words: S. cerevisiae, cystathioninelyase, gene knockout, methionol anabolism, negative regulatory