The phyllosphere as a potential microbial habitat sharing taxa with the Jiang-flavor Baijiu fermentation system: A...

Open spontaneous fermentation, a hallmark of many traditional food systems globally, relies heavily on the surrounding environment for microbial assembly. However, the role of the phyllosphere as a potential microbial habitat within the green spaces adjacent to fermentation facilities remains poorly understood. In this preliminary study, we characterized the epiphytic microbial communities of 11 dominant plant species in the vicinity of a traditional Jiang-flavor Baijiu facility. We identified a rich biodiversity comprising 5495 bacterial and 1678 fungal amplicon sequence variants (ASVs). The phyllosphere exhibited significantly higher bacterial alpha-diversity than fermented grains (Jiupei), positioning it as a highly diverse microbial habitat within the external environment. Notably, we observed extensive taxonomic sharing: 100% of the abundant and always moderate bacterial and fungal ASVs detected in Jiupei were also present on plant surfaces. Furthermore, 70.71% of conditionally rare bacterial ASVs and 68.94% of conditionally rare fungal ASVs from Jiupei were shared with the phyllosphere. These findings demonstrate that multiple microbial taxa co-occur in the phyllosphere and the fermentation system, indicating significant taxonomic sharing across the facility environment. While this exploratory survey does not establish direct microbial transfer, it highlights the phyllosphere as a potential microbial habitat that mirrors the taxonomic composition of the fermentation ecosystem, thereby informing the micro-environmental management of open fermentation systems globally.