Mostafa S A
Zentralbl Bakteriol Naturwiss. 1979;134(5):429-36. doi: 10.1016/s0323-6056(79)80096-8.
Production of L-asparaginase by two soil isolates, identified as S. karnatakensis and S. venezuelae, was investigated under different environmental and nutritional conditions. The presence of carbon sources, other than starch, in the growth medium or amino acids, other than L-asparagine-inhibited the enzyme biosynthesis. L-aspartic inhibited growth and enzyme production, due to a feedback mechanism, and/or lowering the pH value. Both organisms were stimulated to produce more enzyme with increasing concentrations of starch and L-asparagine, however, the optimum starch and L-asparagine concentration depended on the tolerance of the organism to low and high pH, respectively. Aeration stimulated growth, but not enzyme production, and both organisms produced more enzyme in static cultures than in shaken cultures.
对两种被鉴定为卡纳塔克链霉菌和委内瑞拉链霉菌的土壤分离菌株在不同环境和营养条件下生产L-天冬酰胺酶的情况进行了研究。生长培养基中除淀粉外的碳源或除L-天冬酰胺外的氨基酸的存在会抑制酶的生物合成。L-天冬氨酸由于反馈机制和/或降低pH值而抑制生长和酶的产生。随着淀粉和L-天冬酰胺浓度的增加,两种菌株都被刺激产生更多的酶,然而,最佳淀粉和L-天冬酰胺浓度分别取决于菌株对低pH和高pH的耐受性。通气促进生长,但不促进酶的产生,并且两种菌株在静置培养中比在振荡培养中产生更多的酶。