Metabolomic and proteomic analysis reveals the metabolic changes of alkaloids in Ganoderma lucidum fermented tea

Fermentation is the key to the quality formation of Ganoderma lucidum fermented tea (GLFT). This study reveals the metabolic changes of alkaloids and related metabolites during the fermentation process of Ganoderma lucidum tea. Through metabolomics and proteomics analysis, we identified 832 differential metabolites, which are mainly enriched in metabolic pathways such as alkaloids and amino acids. We found changes in 11 alkaloids and related metabolites in these pathways. Twenty-four key differentially expressed proteins associated with alkaloid metabolism were identified. We conducted targeted protein quantification and found that proteins serine hydroxymethyltransferase (SHMT; A0A7J7H649 and A0A7J7I2J8) indirectly regulate alkaloid metabolism via their significant roles in the glycine, serine, and threonine metabolic pathways. This study systematically clarified the correlation between differential proteins and alkaloid metabolites during GLFT processing. The research results provide a theoretical basis for the diversified application of Ganoderma lucidum in tea processing.