Abstract:In order to explore the relationship between the diversity of the microbial community and physicochemical properties in naturally fermented Suanyu，the present study measured the main physicochemical properties of naturally fermented Suanyu and analyzed the microbial diversity by high-throughput sequencing technology.The correlation between dominant microorganisms and physicochemical characteristics was analyzed by the Spearman correlation coefficient.The results showed that the pH value，total acid，amino acid nitrogen，total volatile basic nitrogen，and malondialdehyde content in naturally fermented Suanyu were 4.28-4.38，3.37%-3.86%，0.62 g/100 g-0.69 g/100 g，30.51 mg/100 g-37.10 mg/100 g，and 1.81 mg/kg-2.72 mg/kg，respectively.Five kinds of biogenic amines were detected，including phenethylamine，putrescine，cadaverine，histamine，and tyramine.The microbial diversity showed that Lactobacillus and Clostridium_sensu_stricto_7 were the dominant bacterial genera，and Kazachstania was the main fungal genus.The correlation analysis showed that Lactobacillus and Kazachstania were positively correlated with amino acid nitrogen，and negatively correlated with total volatile basic nitrogen，malondialdehyde，histamine，and cadaverine. The study revealed that Lactobacillus and Kazachstania played an important role in the quality formation of Suanyu，and the results provided a certain theoretical basis for further screening functional microorganisms for Suanyu fermentation.