氨基酸对禾粟链霉菌生物合成ε-聚赖氨酸的影响

Effects of amino acids on ε-polylysine production by Streptom yces graminearus LS-B1

为了探索氨基酸对Streptomyces graminearus LS-B1以葡萄糖发酵生产ε-聚赖氨酸(ε-PL)的影响,分别在发酵过程中添加了16种常见氨基酸。研究结果表明,苯丙氨酸(Phe)、精氨酸(Arg)、酪氨酸(Tyr)、甘氨酸(Gly)、天冬酰胺(Asn)、色氨酸(Try)6种氨基酸对ε-PL合成有一定的促进作用,其中在发酵初始添加Phe且添加浓度为3mmol/L时效果最佳,使产量提高了20%～30%,达到0.488g/L。代谢流量分析(MFA)显示,添加Phe改变了ε-PL合成的代谢流量分布,抑制了磷酸烯醇式丙酮酸(PEP)向莽草酸途径的通量,从而使其更多的流向了ε-PL合成途径。

Effects of sixteen amino acids on the ε-polylysine（ε-PL）production by Streptomyces graminearus LS-B1 were studied using glucose as carbon source. Results showed that ε-PL yield was increased by adding phenylalanine（Phe）, argnine（Arg）, tyrosine（Tyr）, glycine（Gly）, asparagine（Asn）, tryptophane（Try）, respectively. The enhancement of ε-PL production through addition of Phe was obvious. When 3 mmol/L Phe was added at the beginning of fermentation, ε-PL yield was increased by 20%-30%, reaching 0. 488 g/L. The metabolic flux analysis（ MFA） of S. graminearus LS-B1 indicated that metabolic flux distribution of ε-PL fermentation was changed by adding Phe. The flux of phosphoenolpyruvate （PEP） to shikimate pathway was inhibited, while the flux to ε-PL was increased.