Involvement of a Branched-Chain Aminotransferase in Production of Volatile Sulfur Compounds in Yarrowia lipolytica

Abstract

ABSTRACT The enzymatic degradation of l -methionine and the subsequent formation of volatile sulfur compounds (VSCs) are essential for the development of the typical flavor in cheese. In the yeast Yarrowia lipolytica , the degradation of l -methionine was accompanied by the formation of the transamination product 4-methylthio-2-oxobutyric acid. A branched-chain aminotransferase gene (Yl BCA1 ) of Y. lipolytica was amplified, and the l -methionine-degrading activity and the aminotransferase activity were measured in a genetically modified strain and compared to those of the parental strain. Our work shows that l -methionine degradation via transamination is involved in formation of VSCs in Y. lipolytica .