Microbial metabolism of 2-methyl amino acids

Eighty-nine microorganisms were isolated that were able to use 2-methyl amino acids and related compounds as the sole source of nitrogen. All of these cultures produced low levels of ammonia in culture supernatant solutions None was capable of fixing nitrogen gas. Whole-cell and cell-free-extract experiments showed that ammonia was not released directly from the 2-methyl amino acids. All of these strains except those isolated with 2-methylserine as a nitrogen source appeared to metabolize 2-methyl amino compounds by a single enzymatic reaction involving simultaneous decarboxylation and transamination. Pyruvate served as an acceptor for the transamination with the concomitant formation of alanine. The strains utilizing 2-methylserine produced a specific 2-methylserine transhydroxymethylase.