Deep Ocean Water Minerals Promotes the Growth and Cordycepin Production of Cordyceps militaris Fruiting Bodies through Proteomics Regulation

Deep ocean water (DOW) is rich in mineral nutrients, and our previous studies have confirmed that it promotes fungal growth and metabolite production. Cordycepin is a functional metabolite of Cordyceps with anti-inflammatory and antitumor properties. Although Cordyceps militaris can produce a large amount of cordycepin when DOW is used as the culture water, no study has explored the relevant regulatory mechanism through which DOW increases the adenosine and cordycepin contents. Therefore, in this study, we used 2D electrophoresis and proteomic analysis to investigate the effects of DOW with different mineral compositions on proteins in the fruiting bodies of C. militaris and to explore how DOW regulates cordycepin biosynthesis. The results indicated that the use of DOW with high magnesium and calcium contents can increase the production of cordycepin from 6.62 mg/g to 11.40 mg/g by C. militaris fruiting bodies. According to the 2D electrophoresis and proteomic analysis results of the fruiting body proteins of C. militaris cultured with DOW with different concentrations, the expression of 17 and 9 proteins was proportional to the cordycepin content and the concentration of DOW, respectively. Magnesium, sulfate, and other minerals of DOW stimulated the production of cordycepin by promoting the glycolytic pathway, producing more ATP and adenosine. It also increased the production of nucleic acids and adenosine by promoting the pentose phosphate pathway and methionine cycle, thereby promoting the growth and cordycepin production of fruiting bodies.