Genetic Characterization of the Major Lactococcal Aromatic Aminotransferase and Its Involvement in Conversion of Amino Acids to Aroma Compounds

摘要: In lactococci, transamination is the first step of enzymatic conversion aromatic and branched-chain amino acids to aroma compounds. previous work we purified biochemically characterized major aminotransferase (AraT) a Lactococcus lactis subsp. cremoris strain. Here corresponding gene evaluated role AraT in biosynthesis Amino acid sequence homologies with other aminotransferases showed that enzyme belongs new subclass I subfamily gamma; best-characterized representative this aromatic-amino-acid-specific subclass. We demonstrated plays compounds, since inactivation almost completely prevented degradation these acids. It also highly involved methionine leucine conversion. has physiological phenylalanine tyrosine, weakly slowed down growth on medium without affected every tyrosine. However, another induced absence culture medium.