Integrated proteomics and metabolomics analysis of tea leaves fermented by Aspergillus niger, Aspergillus tamarii and Aspergillus fumigatus

• Published in: Food chemistry Vol. 334; p. 127560
• Main Authors: Ma, Yan, Ling, Tie-jun, Su, Xiao-qin, Jiang, Bin, Nian, Bo, Chen, Li-jiao, Liu, Ming-li, Zhang, Zheng-yan, Wang, Dao-ping, Mu, Yong-ying, Jiao, Wen-wen, Liu, Qian-ting, Pan, Ying-hong, Zhao, Ming
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.01.2021
• Subjects: Aspergillus; Carbohydrate; Carbohydrate-active enzyme; Fermentation; Metabolomics; Proteomics; Pu-erh tea; Aspergillus; Metabolomics; Pu-erh tea; Proteomics; Carbohydrate; Carbohydrate-active enzyme; Fermentation
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2020.127560

•Tea leaves were fermented by three species of Aspergillius.•Changes of metabolome in tea leaves were detected.•Fungal enzymes metabolized tea chemical compounds were identified.•Functions of Aspergillius in pu-erh tea fermentation were demonstrated. Post-fermented Pu-erh tea (PFPT) is a microbially-fermented tea with distinct sensory qualities and multiple health benefits. Aspergillus are the dominant fungi in the fermentation and the main contributors to the characteristics of PFPT, so their underlying functions warrant detailed study. Here, tea leaves were fermented by Aspergillus niger, Aspergillus tamarii and Aspergillus fumigatus, and resulting samples (designated as Asn, Ast and Asf, respectively) were analyzed by proteomic and metabolomic methods. Changes to the composition of flavonoids, glycerophospholipids, organo-oxygen compounds and fatty acids resulting from Aspergillus fermentation were observed. Carbohydrate-active enzymes, e.g., endoglucanases and cellulases, for degradation of cellulose, starch, lignin, pectin, xylan and xyloglucan were identified. Glycoside hydrolase, glycosyltransferases, tannase, laccases, vanillyl-alcohol oxidases and benzoquinone reductase were identified and hypothesized to catalyze hydrolysis, oxidation, polymerization and degradation of phenolic compounds. Together, functions of Aspergillius were demonstrated as production of enzymes to change concentrations and compositions of metabolites in tea leaves.