L-Phenylalanine catabolism and L-phenyllactic acid production by a phototrophic bacterium, Rubrivivax benzoatilyticus JA2.

A phototrophic bacterium (Rubrivivax benzoatilyticus JA2) grows at the expense of L-phenylalanine as sole source of nitrogen but not as carbon source. Near stoichiometric yields of L-phenylpyruvic acid (0.4 mM) and L-phenyllactate (0.4 mM) were observed from L-phenylalanine (0.9 mM consumed). Aminotransfarase and dehydrogenase activities involved in the formation of L-phenylpyruvic acid and L-phenyllactate were demonstrated unequivocally in Rubrivivax benzoatilyticus JA2. Growth conditions and carbon sources had an influence on L-phenyllactate production. The process yielded a maximum of 0.92 mM L-phenyllactate from L-phenylalanine (1 mM) when fructose served as carbon source for R. benzoatilyticus JA2.