Effects of m-Tyrosine on Growth and Sporulation of Bacillus Species.

Aronson, John N. (Arizona State University, Tempe), and Gerald R. Wermus. Effects of m-tyrosine on growth and sporulation of Bacillus species. J. Bacteriol. 90:38-46. 1965.-The aromatic amino acid analogue, dl-beta-(3-hydroxyphenyl)alanine (m-tyrosine), reduced sporulation of a strain of Bacillus subtilis to less than 5% of that of control cultures in a glucose-salts minimal medium. The mass-doubling time increased twofold, but maximal growth equivalent to that of control cultures was eventually attained. A decreased growth rate could be maintained in the presence of the analogue for more than 10 doublings, despite incorporation of m-tyrosine-2-C(14) in place of some of the protein phenylalanine. The organism proliferated to chain lengths of 10 to 15 cells. These cells persisted for many hours after maximal growth had been reached, in contrast to normal cultures which had begun to autolyze and sporulate. The response to m-tyrosine of strains of B. cereus, B. thuringiensis, and B. megaterium was like that of B. subtilis. In addition, B. thuringiensis and B. cereus converted m-tyrosine to dihydroxyphenylalanine, which was further oxidized to a melaninlike substance. Growth of a strain of B. stearothermophilus was not slowed by m-tyrosine, but a strain of Escherichia coli grew at a reduced rate.