药物载体用γ-聚谷氨酸产生菌株发酵工艺优化

Optimization of fermentation process forγ-polyglutamic acid-producing strain of pharmaceutical carrier

目的获得分子量为20000~60000的药物载体用γ-聚谷氨酸。方法利用枯草芽孢杆菌在50 L发酵罐中发酵生产γ-聚谷氨酸。通过单因素和正交试验研究碳源、氮源、无机盐、接种量、发酵温度、pH值、发酵周期、谷氨酸钠添加量以及补料量对γ-聚谷氨酸发酵产量的影响;对后处理工艺中硫酸添加量、处理温度、处理时间进行三因素三水平正交试验,得到不同分子量的γ-聚谷氨酸。结果最适发酵培养基:葡萄糖85 g/L,柠檬酸铵5 g/L,谷氨酸钠65 g/L,MgSO40.1 g/L,K2HPO425 g/L;最佳发酵条件为:发酵温度35℃,初始pH7.0,接种量5%,搅拌转速200~500 r/min,10h开始补料,发酵周期60 h;补料培养基配方:葡萄糖120 g/L,谷氨酸钠150 g/L,无水硫酸镁0.1 g/L,补料速度为30 s∶1 s。利用2%的硫酸85℃处理10h即可得到分子量为20000~60000的药物载体用γ-聚谷氨酸原料。结论实验得到的γ-聚谷氨酸可用作药用载体原料,为药物的开发和制备提供新的思路。

Objective To obtain theγ-polyglutamic acid for drug carrier with a molecular weight of 20000~60000.Methods Using Bacillus subtilis to produceγ-polyglutamic acid in a 50 L fermentation tank.Through single factor and orthogonal experiments,the effects of carbon source,nitrogen source,inorganic salt,inoculation amount,fermentation temperature,pH value,fermentation period,sodium glutamate addition and feed amount onγ-polyglutamic acid fermentation were mainly studied;the three-factor and three-level orthogonal test was carried out on the addition of sulfuric acid,the treatment temperature and the treatment time in the post-treatment process to obtainγ-polyglutamic acid with different molecular weights.Results The optimal medium formula was:glucose was 85 g/L,sodium glutamatewas 65 g/L,MgSO4was 0.1g/L,K2HPO4 was 25 g/L,ammonium citrate was 5 g/L;the best fermentation conditions were:fermentation temperature was 35℃,initial pH was 7.0,inoculation amount was 5%,stirring speed was 200~500 r/min,feeding was started after 10 h,fermentation cycle was 60 h;the formula of feed medium was:glucose was 120 g/L,sodium glutamate was 150 g/L,anhydrous magnesium sulfate was 0.1 g/L,the feeding speed was 30 s∶1 s.The 2%sulfuric acid was treated at 85℃for 10 h to obtainγ-polyglutamic acid for drug carrier with molecular weight of 20000~60000.Conclusion Theγ-polyglutamic acid obtained through experiments can be used as a raw material for drug carriers,at the same time this experiment canprovide a new idea for drug development and preparation.