Effect of temperature on the coproduction of chlortetracycline and tetracycline by Streptomyces aureofaciens.

Five strains of Streptomyces aureofaciens of diverse origin and ability to incorporate chloride into chlortetracycline (CTC) were grown at five temperatures of incubation ranging from 20 to 31 C in media of high and low chloride content. Maximal accumulation of CTC and tetracycline (TC) occurred in the 23 to 25 C range. Departure from this range affected the different strains to various degrees in total accumulation. Lower temperatures favored a relative increase in the amount of CTC produced by all strains. Higher temperatures were conducive to the almost exclusive production of TC by some strains but at the expense of an 80 to 90% reduction in potential total yield obtained at lower temperatures. The optimal temperature for maximal biochemical chlorination by some strains of S. aureofaciens was less than the optimal temperature for maximal accumulation of the tetracycline nucleus.