Correlations Between the Bacterial and Fungal Flora and Amino Acid Composition of the Zhuangzu Acid Congee Produced Around the Zuojiang River Basin, Guangxi

In this study, the bacterial, fungal, and amino acid compositions of the Zhuangzu acid congee (ZAC) along the Zuojiang River of Guangxi were analyzed. A total of 14 samples of ZAC were collected in four regions: Fusui (F), Ningming (N), Xiashi (X), and Suxu (S). The predominant bacterial phyla of the four groups were Firmicutes and Proteobacteria. The dominant bacterial genera were <i>Lactobacillus</i>, <i>Bacillus</i>, <i>Schleiferitobacillus</i>, and <i>Acetobacter</i>. The fungal alpha diversity in Group S was significantly lower than that in Groups F, X, and N. PCoA clearly distinguished Group S from Groups F, X, and N. The dominant fungal phylum in Group S was Ascomycota (89.12%), whereas those in Groups F, X, and N were Basidiomycota (38.07%), Ascomycota (30.65%), and Fungi (17.39%). The dominant fungal genera in Group S were <i>Saccharomyces</i> (42.36%) and <i>Pichia</i> (31.66%), whereas those in Groups F, X, and N were <i>Mortierella</i> (17.23%) and <i>Russula</i> (13.34%). The proportions of the six flavor amino acids were relatively high, and all four groups of samples were above 30.00%. PLS-DA of amino acids demonstrated that all four groups of samples could be significantly distinguished. Additionally, the concentrations of taurine, serine, leucine, phosphoserine, asparagine, 1-methylhistidine, and 3-methylhistidine in Group S were significantly greater than those in Groups F, X, and N. Correlation analysis revealed that 6 bacterial and 15 fungal genera were significantly correlated with amino acids, particularly <i>Leuconostoc</i> and <i>Schleiferlactobacillus,</i> among bacteria, as well as <i>Saccharomyces</i> and <i>Russula,</i> among fungi. In conclusion, compared with the disparity in the bacterial community, the disparity in the fungal community was more strongly correlated with the amino acid composition of ZAC. This result indicated that the difference in the fungal community might cause the variation in the amino acid composition of ZAC.