A new cordycepin−producing caterpillar fungus Ophiocordyceps xuefengensis with artificial infection to the host, cultivation of mycelia and stromata

Abstract

Caterpillar fungi have numerous pharmacological and therapeutic applications in traditional medicine, due to a variety of active chemical constituents, such as cordycepin and adenosine. It is imperative to discover new resource for artificial cultivation and bio–metabolite production since the traditional natural species are endangered. In this study, a new strain HACM 001 was isolated and identified as Ophiocordyceps xuefengensis (O. xuefengensis) by rDNA–ITS sequencing. This strain showed the potential of artificial infection to caterpillar larvae leading to mummification, as well as fermentation mycelia in liquid culture and cultivation stromata in solid medium. Eight nucleosides and nucleobases, especially cordycepin and adenosine, were determined and analyzed with HPLC–DAD–Q–TOF–MS/MS technology. Cordycepin was detected in all forms of present O. xuefengensis strain at different contents, among which the highest content (37.1 μg/g) appeared in the stromata cultivated on solid medium. The content of adenosine in mycelia and stromata, respectively, reached 1155 μg/g and 1470 μg/g. Therefore, O. xuefengensis might be an alternative source for obtaining artificial fungus–caterpillar–larvae complex and producing cordycepin and adenosine.