Contrasting microbiomes of raw and ripened Pu-erh tea associated with distinct chemical profiles

Pu-erh tea has become one of the popular and widely consumed teas because of its health benefits resulted from various bioactive compounds that are microbially produced during Pu-erh tea production. We applied 16S rRNA gene amplicon sequencing and analytical tools to investigate microbiomes and associated chemical profiles of five raw and five ripened Pu-erh teas from different manufacturers. Contrasting bacterial and fungal microbiomes of raw and ripened Pu-erh tea samples associated with distinct chemical profiles were revealed. The ripened Pu-erh teas had a higher bacterial diversity but lower fungal diversity than the raw Pu-erh teas. Firmicutes and Proteobacteria were the dominant phyla in the ripened and raw Pu-erh tea, respectively. Cyanobacteria phylum was found very abundant in the raw but rarely present in the ripened Pu-erh tea. Ascomycota was the dominant fungal phylum in both ripened and raw Pu-erh tea. Tea polysaccharide and gallocatechin gallate were the characteristic chemicals in the ripened Pu-erh tea; while caffeic acid, caffeine, EGC, ECG, EGCG, C, and GA were more representative in the raw Pu-erh tea. These results will assist in further cultivating and characterizing the representative microorganisms in Pu-erh teas of different origins, and improve our understanding of microbial-mediated Pu-erh tea production process.