Composition and changes of microflora in the manufacturing process of traditional hurood

Abstract

Hurood is a kind of cheese product by a unique Mongolian dairy artisanal production method. Because the microbes directly contribute to the quality and physicochemical properties of hurood, it is essential to understand the microbial structure and properties of hurood. In this study, we separated and detected 319 species of lactic acid bacteria (LAB) from four different fermentation stages of hurood. The predominant LAB isolates were Lactococcus lactis, which represented 52.4% of all isolates. The metagenomic sequencing technology results revealed that the microbial diversity decreased gradually during the hurood manufacturing process, and some non-LAB from the environment were detected. A correlation analysis showed that L. lactis could inhibit the growth and reproduction of non-LAB (P < 0.05). A metabolic pathway difference analysis showed that the biosynthesis pathways of B vitamins and unsaturated fatty acids and the carbohydrate degradation pathway were significantly enriched in hurood (P < 0.05), which might affect its texture and flavor development. In conclusion, this study provides a better understanding of the dynamic changes in the microbial community and dominant microbes at each fermentation stage in hurood, which provides theoretical support for optimizing the microbial structure of the hurood fermentation stages and improving product quality.