Cloning of the aminotransferase gene ARO8 and its influence on the production of methionol in Saccharomyces cerevisiae

Methionol is an important volatile sulphur flavor compound.It can be produced in Saccharomyces cerevisiae using L- methionine by the Ehrlich pathway.To verify aminotransferase'effect, gene ARO8 encoding aminotransferase was cloned from S.cerevisiae S288C, and the gene ARO8 was inserted into the S.cerevisiaeE.coli shuttle constitutive expression vector pYES- pgk, generating a recombinant vector pYES- pgk- ARO8.The vector pYES- pgk- ARO8 was then transformed into S.cerevisiae S288C.The results indicated that the encoding gene shared 100% homology with the aromatic aminotransferase Ⅰ gene ARO8 reported in NCBI GenBank.A recombinant strain S.cerevisiae AR8 was constructed and screened successfully.The aminotransferase activity of S.cerevisiae AR8 was 187U /mL, which was increased by 28.8% compared to what in S.cerevisiae S288C.Methionol yield of AR8 in shaking flask reached 0.76g /L and it was increased by 28.8%.These results showed that aminotransferase Aro8p and gene ARO8 of S.cerevisiae played an important role in methionol anabolism, and the gene ARO8 over-expression was help to methionol yield.