The Microbiome and Metabolites in Fermented Pu-erh Tea as Revealed by High-Throughput Sequencing and Quantitative Multiplex Metabolite Analysis

PLoS One. 2016 Jun 23;11(6):e0157847. doi: 10.1371/journal.pone.0157847. eCollection 2016.

Abstract

Pu-erh is a tea produced in Yunnan, China by microbial fermentation of fresh Camellia sinensis leaves by two processes, the traditional raw fermentation and the faster, ripened fermentation. We characterized fungal and bacterial communities in leaves and both Pu-erhs by high-throughput, rDNA-amplicon sequencing and we characterized the profile of bioactive extrolite mycotoxins in Pu-erh teas by quantitative liquid chromatography-tandem mass spectrometry. We identified 390 fungal and 629 bacterial OTUs from leaves and both Pu-erhs. Major findings are: 1) fungal diversity drops and bacterial diversity rises due to raw or ripened fermentation, 2) fungal and bacterial community composition changes significantly between fresh leaves and both raw and ripened Pu-erh, 3) aging causes significant changes in the microbial community of raw, but not ripened, Pu-erh, and, 4) ripened and well-aged raw Pu-erh have similar microbial communities that are distinct from those of young, raw Ph-erh tea. Twenty-five toxic metabolites, mainly of fungal origin, were detected, with patulin and asperglaucide dominating and at levels supporting the Chinese custom of discarding the first preparation of Pu-erh and using the wet tea to then brew a pot for consumption.

MeSH terms

  • Bacteria / classification
  • Bacteria / genetics
  • Biodiversity
  • Computational Biology / methods
  • Fermentation*
  • Fungi / classification
  • Fungi / genetics
  • High-Throughput Nucleotide Sequencing
  • Metabolome*
  • Metabolomics* / methods
  • Metagenome
  • Metagenomics* / methods
  • Microbiota*
  • Tea / chemistry*
  • Tea / genetics
  • Tea / microbiology*

Substances

  • Tea

Grants and funding

The support provided by China Scholarship Council during a visit of Yongjie Zhang to Berkeley (201208140025) is acknowledged. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.