| ABSTRACT: Objective Investigate the microbial community diversity, and potential functions of the lactic acid bacteria (LAB) in these suancai. Methods high-throughput sequencing using Oxford Nanopore technology was performed on 30 traditionally suancai samples collected from five different climatic and geographical regions in Ynnan Province. Results The results revealed that within the class Bacilli, a total of 1 order, 5 families, 10 genera, and 70 species were annotated. At the genus level, Lactobacillus was the absolutely dominant genus, with its relative abundance ranging from 66.13% to 96.92%. followed by Enterococcus, Leuconostoc, Pediococcus, and Weissella. At the species level, Lactobacillus fermentum, Companilactobacillus alimentarius, Lactobacillus delbrueckii, Enterococcus faecalis, and Levilactobacillus koreensis were identified as the dominant species, with significant differences in species composition across regions. Samples from the tropical regions of Xishuangbanna Dai Autonomous Prefecture and Dehong Dai and Jingpo Autonomous Prefecture exhibited higher LAB diversity than those from the more temperate regions of Kunming, Qujing, and Dali Bai Autonomous Prefecture.Cluster analysis showed that tropical samples grouped together, while temperate samples formed a separate cluster, indicating that climate and geographical origin are major factors influencing LAB community composition. Functional prediction indicated that chemoheterotrophy and fermentation were the primary energy metabolism pathways. Regional differences were observed in functions such as nitrite reduction, ammonification, and nitrogen respiration. In the samples from Dali Bai Autonomous Prefecture, the abundance values of chemoheterotrophy and fermentation functions showed a positive correlation with the total acid content, both being the highest. In contrast, Xishuangbanna Dai Autonomous Prefecture and Dehong Dai and Jingpo Autonomous Prefecture were characterized by higher abundance values of nitrate reduction function and higher nitrite content. Meanwhile, in Qujing and Kunming areas, the abundance values of nitrite ammonification and nitrogen respiration functions were higher, and their nitrite content showed a negative correlation with these functions, being significantly lower than that in other regions. Conclusion This study reveals the community differences, diversity, and potential functions of LAB in Suan from different regions of Yunnan Province, providing a theoretical basis for the subsequent screening of functional strains and the development and utilization of regional characteristic lactic acid bacteria resources. |
