Shoumei, Silver Needle Age Along Different Microbial Paths
A multi-omics study in LWT reports that shoumei and silver needle stored for one, three and seven years develop distinct bacterial communities and distinct chemistry.
Shoumei and silver needle follow different microbial paths as they age, and those paths track different chemical changes, a study in the journal LWT reported.
The study, by Zhengjie Chang and colleagues, examined shoumei (寿眉), the leafiest of the white grades, and silver needle (白毫银针, baihao yinzhen), which is buds only, after one, three and seven years of storage. The researchers sequenced the bacteria and fungi present on the stored leaf and paired that with metabolomics, the chemical profiling of the leaf.
The bacterial communities separated by grade. Sphingomonas dominated the shoumei samples and Pedobacter the silver needle samples, the researchers reported, and Herbaspirillum rose significantly in seven-year shoumei. Fungal diversity was lower overall and shifted more gradually across the storage years than bacterial diversity did.
The chemistry moved in parallel. The team detected 2,778 secondary metabolites, of which 708 differed significantly by storage duration. Flavonoids, a large family of plant compounds, changed most, with 68 individual flavonoids altered by aging. Purine gallate esters increased consistently with storage in both grades.
The team ran a separate correlation analysis for each grade. In shoumei's network, baicalein, 5-deoxy-5'-methylthioadenosine and kaempferol-3-O-rutinoside sat at the center; in silver needle's own network, baicalein and 5-deoxy-5'-methylthioadenosine recurred as central compounds, paired with a different set of core bacterial genera. The researchers called the close association a clue to the microbial community's possible role in shaping the tea's aging chemistry, not yet a settled causal account.
The summary reports microbiology and chemistry, not sensory results, and the work makes no health claim. The account here follows a Chinese-language science-press summary of the paper together with the journal's bibliographic record for it; the full text was not available.
Sources: ebiotrade.com summary · Chang et al., LWT (2026), DOI