金色链霉菌连续培养特性及其动力学研究

研究了以碳源为限制性底物时金色链霉菌连续培养特性和动力学。实验结果表明,Streptomycesaureofaciens的比生长速率与限制性底物浓度的关系符合Monod方程,并得到动力学参数max=0.0649h-1和Ks=8.47gL-1。菌体和产物金霉素chlortetracycline的得率系数分别为1.866gg-1和2.580gg-1,维持系数为0.0051g(gh)-1。菌体和产物的最大产率为0.859g(Lh)-1和0.0299g(Lh)-1。菌体和产物对氧的得率系数分别为60.81gmol-1和64.33gmol-1,对氧的维持系数为0.3390mmol(gh)-1。磷氧比P/O等于2.77。呼吸商RQ与m呈线性正比关系,随着m的减小,碳源代谢流从酵解途径逐渐向戊糖途径增强。代谢流的这种迁移有利于产物金霉素chlortetracycline的合成。

Study on the Kinetics and Characteristics of Streptomyces aureofaciens in Continuous Cultivation

The kinetics and characteristics of Streptomyces aureofaciens in continuous cultivation with carbon source used as a limited substrate were investigated. It is found that Monod Equation can express the relationship between the specific growth rate and the residual saccharide concentration, in which mmax=0.0649h-1 and Ks=8.47gL-1. The biomass and Chlortetracycline( CTC) yield coefficients against carbon source are 1.866gg-1 and 2.580gg-1, respectively, and the growth maintenance coefficient is 0.0051g(gh)-1. The maximum biomass yield and the CTC yield are 0.859g(Lh)-1 and 0.0299g(Lh)-1, respectively. The biomass and CTC yield coefficients against oxygen are 60.81gmol-1 and 64.33gmol-1, respectively, and the growth maintenance coefficient against oxygen is 0.339mmol(gh)-1 and the ratio of P/O is 2.77. The relationship between respiratory quotient RQ and m is linear. With m decreasing, the metabolic flux of carbon source shifts increasingly from glycolysis pathway to hexosephophate pathway. The shift of metabolic flux is favourable to Chlortetracycline biosynthesis.