摘要
由于基因工程菌株与野生菌株的发酵体系及工艺上存在较大差异,现有工艺难以满足基因工程菌的工业化发酵需求,因此本课题以产表面活性素基因工程菌株为对象开展其代谢规律及发酵工艺研究。利用模拟发酵罐对比野生菌株及基因工程菌株的生长代谢规律,同时对基因工程菌株的诱导剂及合成前体添加、消泡方式及通气量等发酵参数进行优化。研究表明:野生菌株和基因工程菌株代谢规律不同,基因工程菌株OD_(600)峰值为野生菌株的20倍;合成前体Leu和诱导剂IPTG的添加时机对表面活性素产率影响较大,优化得到在培养基中添加合成前体共同灭菌,且接种2.5 h后加入诱导剂的方式对表面活性素的表达最佳;基因工程菌株发酵过程中耗氧量大且产生大量泡沫,建立了包括泡沫回流工艺和植物油消泡的2种消泡方式;优化后最佳通气比为1.0 vvm、接种量为4%、发酵时长为60 h的条件下,10 L模拟发酵罐表面活性素产率达到14.2 g·L^(-1)。本研究为该类基因工程菌株工业化应用奠定坚实基础。
The surfactin(lipopetide biosurfactant)has strong temperature-tolerance,and salinity-tolerance,and it can enhance the oil recovery by reduction of interfacial tension,emulsification,wettability alteration and so on,presenting a considerable application prospect.Nowadays fermentation technology hardly meets the requirements of gene-engineered strain due to the various difference of fermentation process between the wild and gene-engineered strain.In this paper,research on the metabolic law and fermentation process of surfactin-producing gene-engineered strains was carried out.The metabolic rules between wild strain and gene-engineered strain were compared by using simulated fermentation tank;At the same time,the fermentation parameters such as inducer and synthetic precursor addition,defoaming method and ventilation rate of gene-engineered strains were optimized.The research showed that the metabolic laws of the wild strain and the gene-engineered strain were different,and the peak OD_(600) of the gene-engineered strain was 20 times that of the wild strain;the timing of adding the synthetic precursor Leu and the inducer IPTG had a great influence on the yield of surfactin.Synthetic precursors were added to the base for co-sterilization,and the method of adding inducers 2.5 h after inoculation was the best for the expression of surfactin;During the fermentation process of gene-engineered strains,the oxygen consumption was large and a large amount of foam was produced,so a process including foam reflux was established.There were two defoaming methods of defoaming and adding vegetable oil.After optimization,the optimal aeration ratio was 1.0 vvm,the inoculation amount was 4%,and the fermentation time was 60 h.Under above conditions,the yield of surfactin in a 10 L simulated fermenter reached 14.2 g·L^(-1).This study lays a solid foundation for the industrial application of such gene-engineered strains.
作者
陈子慧
王静
胡婧
高光军
林军章
汪卫东
汪庐山
CHEN Zi-hui;WANG Jing;HU Jing;GAO Guang-jun;LIN Jun-zhang;WANG Wei-dong;WANG Lu-shan(Postdoctoral Work Station of Sinopec Shengli Oilfield Company,Dongying Shandong 257001,China;Institute of Petroleum Engineering and Technology,Sinopec Shengli Oilfield Company,Dongying Shandong 257000,China;Sinopec Key Laboratory of Microbial Enhanced Oil Recovery,Dongying Shandong 257000,China;Sinopec Shengli Oilfield Company,Dongying Shandong 257001,China)
出处
《当代化工》
CAS
2022年第10期2375-2380,共6页
Contemporary Chemical Industry
基金
山东省自然科学基金青年项目,油藏极端微生物界面行为及润湿机制研究(项目编号:ZR2021QE285)
中国石化微生物采油重点实验室课题,油藏微生物界面润湿改性机制及调控方法研究(项目编号:KL22058)
中石化胜利油田博士后课题,微生物驱油藏界面生物改性机制和调控方法研究(项目编号:YKB2014)。
关键词
基因工程
高产脂肽
发酵工艺
泡沫回收
工业化应用
Gene-engineering
High quantity of surfactin
Fermentation process
Foam recycling
Industrial application
