生物技术通报 ›› 2016, Vol. 32 ›› Issue (12): 47-52.

• 技术与方法 • 上一篇    下一篇

基因组DNA去甲基化法改良蛹虫草菌株高产虫草素及性状稳定性评价

朱巍巍12,李莉2,陈飞2,李杨2,王艳华2,包永明1   

  1. 1. 大连理工大学生命科学与技术学院,大连 116024;
    2. 辽宁省微生物科学研究院,朝阳 122000
  • 收稿日期:2016-04-11 出版日期:2016-12-25 发布日期:2016-12-07
  • 作者简介:朱巍巍,男,博士研究生,研究方向:食用菌育种及标准化栽培;E-mail:zhuweiwei@vip.163.com
  • 基金资助:

    辽宁省农业公关及产业化项目(2015209002),辽宁省农业领域重点培养青年人才项目(2014034)

Enhanced Cordycepin Production of Cordyceps militaris by Genomic DNA Demethylation and the Evaluation of Its Stability

ZHU Wei-wei12,LI Li2,CHEN Fei2,LI Yang2,WANG Yan-hua2,BAO Yong-ming1   

  1. 1. School of Life Science and Biotechnology,Dalian University of Technology,Dalian 116024;
    2. Liaoning Research Institute of Microbiology,Chaoyang 122000
  • Received:2016-04-11 Published:2016-12-25 Online:2016-12-07

摘要:

基因组DNA去甲基化能够激活沉默基因,改变次级代谢产物谱,是一种全新的菌种改良途径。利用不同浓度的DNA甲基化酶抑制剂5-氮杂胞苷(5-azaC)处理蛹虫草菌株CM-L1,降低基因组DNA甲基化水平,高效液相色谱筛检得到改良株LB-C3和LD-A7,菌丝体中虫草素含量分别提升127%和144.3%。LD-A7不能形成子实体,推测与关键的DNA甲基化修饰作用被改变有关。经5次继代培养后,以虫草素含量为指标考察性状稳定性。随传代次数增加,基因组中甲基化的DNA含量增加,液体发酵菌丝体中的虫草素含量均显著降低,但是子实体中虫草素含量非常稳定,改良的菌株更适合栽培生产而非工业发酵。

关键词: DNA去甲基化, 5-氮杂胞苷, 蛹虫草, 虫草素

Abstract:

Genomic DNA demethylation may activate silenced gene,which alters secondary metabolite spectrum,and therefore it is a completely novel approach for strain improvement. Using different concentrations of DNA methyltransferase inhibitor 5-azacytidine(5-azaC)to treat the Cordyceps militaris CM-L1,then the genomic DNA methylation level reduced. Further,the improved strains LB-C3 and LD-A7 were acquired by screening with high performance liquid chromatography,and in which the contents of cordycepin in mycelium increased by 127% and 144.3% respectively. LD-A7 could not form a fruiting body,which was speculated to be related to the role of DNA methylation changed. The stability was investigated after 5 times subculture using the content of cordycepin as an indicator. With the subculture times increased,the methylated DNA in the genome increased,and the cordycepin in mycelium of liquid fermentation significantly decreased;however,the content of cordycepin in fruiting bodies was very stable,indicating that improved strains were better suited to the cultivation rather than production in industrial fermentation.

Key words: DNA demethylation, 5-azaC, Cordyceps militaris, Cordycepin

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