Dynamic changes in the diversity and function of bacterial community during black tea processing.

Area of Science:

• Microbiology
• Food Science
• Biotechnology

Background:

• Black tea is the most produced and consumed tea globally.
• Bacterial communities are crucial for black tea quality, yet their roles are understudied.
• Understanding microbial dynamics is essential for optimizing black tea processing.

Purpose of the Study:

• To investigate the dynamic changes in bacterial communities during black tea processing.
• To identify the specific roles of bacteria in the biochemical transformations of black tea.
• To correlate bacterial abundance with key quality-determining compounds in black tea.

Main Methods:

• Analysis of bacterial community composition and structure using high-throughput sequencing.
• Prediction of bacterial community functions using bioinformatics tools.
• Correlation analysis (Redundancy and Pearson's) between bacterial abundance and tea chemical components.

Main Results:

• Sphingomonas and Variovorax were identified as dominant bacterial genera throughout black tea processing.
• Enzymatic activities related to glycolysis, fermentation, and polysaccharide breakdown were significantly elevated during rolling and fermentation stages.
• Increased abundance of amino acids, soluble sugars, theaflavins, thearubigins, and theabrownins correlated with specific bacterial populations.

Conclusions:

• Bacterial communities play a significant role in the quality formation of black tea.
• Specific bacterial genera and their metabolic functions are associated with the development of key flavor and aroma compounds.
• This research provides novel insights into the microbial ecology of black tea processing and identifies core functional bacteria.