OPTIMUM CONDITIONS FOR HISTIDINE PRODUCTION BY FED-BATCH CULTURE OF BREVIBACTERIUM-FLAVUM

This study deals with the optimum conditions for histidine production by a mutant derived from Brevibacterium flavum. The mutant required uracil for growth and produced histidine and the inevitable by product, glycine, at high dissolved oxygen concentrations. The most characteristic feature of this mutant was its carbon source requirement. Neither glucose nor acetate alone could support growth and histidine production. Using exponential fed-batch culture, the following results were obtained. Growth of the mutant could be promoted and maintained at a desired value only when the molar consumption ratio of acetate and glucose (A/G consumption ratio) was in the range of 0.7 to 2.7. A high amount of glutamate was synthesized in addition to histidine and glycine at a low A/G consumption ratio (0.7 to 1.5). An A/G consumption ratio of 2.4 was determined to be optimal for histidine production in terms of specific production rate.