摘要
筛选能够有效降解甘草药渣的菌株,优化菌株的纤维素酶生产工艺。从腐烂的甘草及土壤中筛选甘草药渣降解菌,结合形态学观察及18S r DNA测序确定菌株的分类地位;考察了不同因素对菌株发酵的影响;采用L9(34)正交分析法确定菌株最佳产酶条件;利用菌株生产的纤维素酶对甘草药渣进行酶解研究。确定分离菌株为Penicillium oxalicum,命名为草酸青霉G2。正交分析结果表明,药渣含量、发酵时间对G2的发酵有显著影响(P<0.05,P<0.05);在最佳产酶工艺条件下,测得G2滤纸酶活力3.43 U/m L、内切酶活力16.89 U/m Lu;甘草药渣的酶解结果表明,G2生产的纤维素酶(G2酶)对甘草药渣的酶解效率优于商品酶。此外,甘草药渣经酶解以后,甘草总黄酮提取率明显升高。对甘草药渣降解菌的筛选以及对菌株的产酶工艺研究,旨在为合理利用甘草药渣以及生产成本低廉、性能优良的纤维素酶奠定基础。
This work aims to screen the strains that can degrade Glycyrrhiza uralensis residues（GUR）and to optimize the production process of cellulase by the strains. First,the strains were screened from decayed Glycyrrhiza uralensis and soil,and then were identified through morphological observation and 18S rDNA. Second,the effects of different factors on the fermentation of the isolated strains were studied,and the orthogonal test L9（34）was used to determine the optimal condition of producing enzyme. The produced cellulase complex was used to investigate how the enzymatic hydrolysis of GUR was proceeding. According to the results,the isolated strain was identified as Penicillium oxalicum,designated as G2. The effects of concentrations of herb residues and fermentation time on cellulase production of G2 were significant（P〈0.05 and P〈0.05）. Under the optimal conditions,the FPase activity reached 3.43 U/mL and EG activity reached 16.89 U/mL. Compared with commercial cellulase,the cellulase by G2 was more efficient in degrading GUR. In addition,the extraction rate of total flavonoids from Glycyrrhiza uralensis Fisch was significantly higher after enzymatic hydrolysis. Here screening the GUR-degrading bacteria and studying the process of producing the enzyme from the GUR laid the foundation for the rational utilization of GUR and the production of cellulase with low cost and fine performance.
出处
《生物技术通报》
CAS
CSCD
北大核心
2017年第12期125-131,共7页
Biotechnology Bulletin
基金
江苏省自然科学基金项目(BK20161048)
江苏省中药资源产业化过程协同创新中心第三批重点项目(ZDXM-3-17)
江苏省产学研前瞻性联合研究项目(BY2015008-04)
关键词
甘草药渣
纤维素酶
草酸青霉
Glycyrrhiza uralensis residues
cellulase
Penicillium oxalicum
