THE SYNTHESIS OF L-TYROSINE AND ITS AROMATIC-RING-SUBSTITUTED ANALOGS BY MICROBIAL-CELLS CONTAINING TYROSINE PHENOL-LYASE

The cells of Citrobacter intermedius containing tyrosine phenol-lyase catalyzed the formation of tyrosine; 3-F, 2-F, 3,5-F-2, 2-Cl, 2-Me, and 3-Me substituted tyrosines; and 2,4-dihydroxyphenylalanine (DOPA) from pyruvate, an ammonium salt, and phenol derivatives. The initial rates of synthesis for substituted phenols ranged from 18 to 84% of the rate of the synthesis of unsubstituted tyrosine. By-products were formed in all cases except for the syntheses of tyrosine and fluorotyrosines. C. intermedius cells produced virtually no DOPA from pyrocathechol, whereas the cells of Erwinia herbicola synthesized 4 g/l of DOPA. The opposite relationship was observed with 3-fluorotyrosine.