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

Abstract

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

CLC Number:

10.13560/j.cnki.biotech.bull.1985.2016.12.009

ZHU Wei-wei，LI Li,CHEN Fei,LI Yang,WANG Yan-hua,BAO Yong-ming. Enhanced Cordycepin Production of Cordyceps militaris by Genomic DNA Demethylation and the Evaluation of Its Stability[J]. Biotechnology Bulletin, 2016, 32(12): 47-52.

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