Diversity and potential function of bacterial communities during milk fermentation of Kazak artisanal cheese

Abstract

Kazak artisanal cheese is a traditionally fermented food from the Uighur Autonomy Region of Xinjiang, China. In this study, we used Illumina MiSeq high-throughput sequencing technology to explore the microbial diversity during the milk fermentation of Kazak traditional hand-fermented cheese in Xinjiang, by analyzing the V3–V4 variable region of the bacterial 16S rRNA gene. Results showed that Lactobacillus and Lactococcus from the Firmicutes group comprised the dominant genera. Lactobacillus, Lactococcus, Acinetobacter, Anoxybacillus, Macrococcus, Acetobacter, Kurthia, Lelliottia, and Leuconostoc were identified as the key microbial groups during the milk fermentation of cheese. Correlation analysis also indicated that Lactobacillus had strong negative connections with Lactococcus, Acinetobacter, Macrococcus, Anoxybacillus, and Staphylococcus. The genera of Lactobacillus and Lactococcus (e.g., Lactobacillus paracasei B1, Lactobacillus sp. B4 and Lactococcus lactis B11) had higher enzyme activity characteristics according to the enzyme activity experiments. Subsequent gene function prediction indicated that the microorganisms in fermented milk products mainly contributed to carbohydrate and amino acid metabolism, which might be closely related to the development of the flavor of the cheese. Our study provides a theoretical basis for understanding the succession of bacteria and the application of potential functional microorganisms in Kazak cheese.