Highlights

• Microbial activity, primarily by Aspergillus, converts insoluble polysaccharides into soluble forms predominantly during the early stages of Pu-erh tea fermentation.
• The study identifies a sequential consumption and production pattern of monosaccharides and carboxylic acids, respectively, during dynamic fermentation stages.
• This research establishes a novel linkage between microbiome dynamics and polysaccharide degradation products, providing insights for optimizing Pu-erh tea production and quality.

Summary

This study explores the breakdown of insoluble polysaccharides during the fermentation of Pu-erh tea, focusing on the interaction between microbiota and metabolites. It examines the changes in microbial communities and the corresponding transformation of polysaccharides into metabolites that affect tea quality.

Using genomics and metabolomics, the research tracks the consumption of certain monosaccharides for microbial energy supply during early and middle fermentation stages, and the accumulation of carboxylic acids in later stages, which influence tea taste and properties. Key fungi like Aspergillus, Rasamsonia, and bacteria such as Bacillaceae and Lactobacillaceae play significant roles in these processes.

The findings illuminate the metabolic pathways of polysaccharide degradation, offering insights to enhance Pu-erh tea’s quality and health benefits. They also lay a foundation for future improvements in fermentation control.

X. Bian et al., “Microbiota drive insoluble polysaccharides utilization via microbiome-metabolome interplay during Pu-erh tea fermentation,” Food Chemistry, vol. 377, p. 132007, May 2022, doi: 10.1016/j.foodchem.2021.132007.