Metabolomics analysis reveals the changes of metabolites in Cordyceps militaris during subculture

Abstract

Cordyceps militaris (C. militaris) strain is highly prone to degeneration during subculture. The morphological changes in colonies and fruiting bodies during subculture were observed and the metabolites changes were analyzed using metabolic profiling. The results showed that an obvious degeneration occurred in strain beginning from the fifth generation. Antioxidant enzymes activities gradually declined and MDA content slowly increased during subculture. LC-MS results indicated 121 metabolites were identified. K-means clustering analysis results suggested the 5th and 7th clusters had the greatest number of metabolites, mainly including organic acids and derivatives, nucleoside compounds, steroid compounds, fatty acids and their derivatives, and some peptide compounds. Furthermore, the characteristic metabolites levels progressively declined during subculture, which led to the degeneration. The reduced L-glutathione content in the 7th generations was significantly higher than that in the 1st generations, suggesting that C. militaris cells enhanced their synthesis capacity to counter oxidative damage during subculture.