重组大肠杆菌产耐热α-L-鼠李糖苷酶高密度发酵条件的优化
Optimization of High-Density Fermentation Conditions for Thermostable α-L-Rhamnosidase Produced by Recombinant E.Coli
葛林 1刘英英 1周芳名 1展凌玲1
作者信息
- 1. 苏州健雄职业技术学院生物医药学院,江苏太仓 215411
- 折叠
摘要
为了减少乙酸的生成,提高重组大肠杆菌生产耐热α-L-鼠李糖苷酶的产量,考查了指数流加培养、两阶段指数流加培养、诱导温度、诱导pH对重组大肠杆菌发酵生产耐热α-L-鼠李糖苷酶(TstRhaA)过程中乙酸含量和酶产量的影响.确定最佳发酵工艺:诱导前比生长速率0.2 h-1,诱导后比生长速率0.18 h-1,诱导温度33℃,pH7.2.在最佳发酵工艺条件下,乙酸浓度始终保持在0.8 g/L以下,菌体干重(DCW)最大为69.6 g/L,最高酶活力为589.0 U/mL,是摇瓶发酵的23.4倍,实现了重组大肠杆菌高密度发酵生产TstRhaA.研究结果表明,调节大肠杆菌高密度发酵过程中乙酸含量在合适范围内,能够实现TstRhaA的高效生产,这对其他酶的高密度表达具有重要指导意义.
Abstract
In order to reduce the production of acetic acid and improve the production of thermostable α-L-rhamnosi-dase from recombinant E.coli,the effects of exponential fed-batch,two-stage exponential fed-batch,induction temper-ature and induction pH on acetic acid content and enzyme yield were investigated in the fermentation process of recom-binant E.coli for thermostable α-L-rhamnosidase(TstRhaA).The optimal fermentation process was determined as fol-lows:specific growth rate before induction was 0.2 h-1,specific growth rate after induction was 0.18 h-1,induction tem-perature was 33℃,pH 7.2.Under the optimal fermentation conditions,the concentration of acetic acid was always be-low 0.8 g/L,the maximum DCW was 69.6 g/L,and the highest enzyme activity was 589.0 U/mL,which was 23.4 times of that of shake flask fermentation.The results showed that efficient production of TstRhaA could be achieved by adjust-ing the acetic acid content in an appropriate range during high-density fermentation in E.coli,which had important guiding significance for the high-density expression of other enzymes.
关键词
α-L-鼠李糖苷酶/大肠杆菌/乙酸/高密度发酵Key words
α-L-rhamnosidase/Escherichia coli/acetic acid/high density fermentation引用本文复制引用
基金项目
太仓市基础研究计划-面上项目(TC2020JC17)
江苏省高等学校基础科学(自然科学)研究面上项目(21KJB220015)
苏州健雄职业技术学院"两金"项目(2022)()
出版年
2024
NETL
NSTL
万方数据