High-throughput screening of Cordyceps militaris for cordycepin production by UV-DES compound mutation

In order to further improve the cordycepin yield,Cordyceps militaris(C. militaris)CICC 14014 was considered as the starting strain for protoplast compound mutation. The protoplasts of the strain were induced by ultraviolet-diethyl sulfate(UV-DES). Then,a high cordycepin yield and stable genetic strain was obtained by screening with 96-well microplates and triangle bottles. Through primary screening with 96-well microplates,54 mutant strains with a yield greater than 6 g/L cordycepin were obtained. A strain of cordycepin high yield mutant strain UD10-2 was screened out by secondary screenings with triangle bottles. The cordycepin production obtained by C. militaris UD10-2 mutant was 11.32 g/L in liquid surface culture,which was enhanced by 108.47% more than the original strain(5.43 g/L). The results of subculture test showed that the mutant strain had stable hereditary characteristics after 20 generations.