在林可霉素生物合成过程中铵离子调控作用的酶学研究  

Enzymology study on regulatory effect of NH_4^+ during lincomycin fermentation

作　　者：李啸[1] 储炬[1] 张嗣良[1] 庄英萍[1] 杭海峰[1] 

机构地区：[1]华东理工大学生物工程学院国家生物反应器重点实验室,上海200237

出　　处：《工业微生物》2009年第4期1-6,共6页Industrial Microbiology

基　　金：上海市科委重点科技攻关项目(064319033)

摘　　要：在FUS-50L发酵罐内,用林可链霉茵发酵生产林可霉素。研究发现,NH_4^+对林可霉素发酵过程具有显著的调控效应:补入硫酸铵前,发酵液中的NH_4^+浓度由3.0 mmol/L消耗至1.0mmol/L以下的控制过程非常关键,这样可能使林可霉素合成酶大量合成,同时,解除了NH_4^+对谷氨酰合成酶(GS)的阻遏效应;20～24 h,尽可能提高硫酸铵的平均补入速率,但最高NH_4^+的瞬时浓度应控制在19.0 mmol/L以下,一方面可缩短生物量的积累时间,另一方面可避免过高浓度的NH_4^+对GS的抑制作用;24 h后逐渐降低NH_4^+的平均补入速率,使主代谢流转入次级代谢;在发酵中期和后期,应将最低NH_4^+浓度控制在3.0～4.0 mmol/L的范围内,避免铵离子对GS的阻遏效应,GS比活力与林可霉素的产量呈正相关关系。最终建立了动态的硫酸铵补加工艺。In the course of fermentation for producing lincomycin by Streptornyces lincolnensis in the FUS-50 L fermenter, it was found that the NH4^＋ had obvious influence on the lincomycin fermentation. Before feeding ammonium sulfate into fermentation broth, the control procedure during the NH4^＋ being consumed from 3.0 mmol/L to 1.0 mmol/ L was very important： amount of lincomycin synthetase were synthesized and the repression effect of NH4^＋ on glutamine synthetase （GS） was derepressed. In the period of 20-24 h, the average rate of addition of ammonium sulfate should be increased as soon as possible （the highest instantaneous concentration of NH4^＋ 〈 19.0 mmol/L） so as to shorten the time for biomass accumulation and avoid excessive concentration of NH4^＋ which would inhibit sugar metabolism enzyme and GS. After 24 hours, the average rate of addition of ammonium sulfate should be decreased gradually in order to make the main metabolism flow divert to secondary metabolism flow. In the mid-late and late stage, the lowest concentration of NH4^＋ should be controlled between 3.0 -- 4.0 mrnol/L which would avoid repression effect from NH4^＋ , and it was found that the specific activity of GS of Streptomyces lincolnensis had a positive correlation with lincomycin production. Finally, the dynamic （NH4）2SO4 supplement strategy was established.

关 键 词：林可链霉菌 林可霉素 补料分批发酵 谷氨酰胺合成酶 丙氨酸脱氢酶 

分 类 号：TQ927[轻工技术与工程—发酵工程]