Induction of tyrosinase by L-methionine in Streptomyces antibioticus.

Investigations were carried out to establish conditions favorable for the formation of tyrosinase, an inducible metalloenzyme synthesized by Streptomyces antibioticus. It was determined that the size of the inoculum and age of the culture as well as the temperature of incubation were important factors for enzyme synthesis. Induction of tyrosinase by S. antibioticus appears to be specific for L-methionine with maximal enzyme synthesis observed at 0.1 mM. Addition of CuSO4 and D-glucose at the time of induction also are important for increased enzyme activity. Inhibition of tyrosinase synthesis was observed with actinomycin D, rifampicin, and chloramphenicol suggesting that both transcriptional and translational events are required for tyrosinase induction.