Fermentation technology is of great significance for food preservation; through fermentation, while extending the shelf life of food, it can also improve the sensory quality of food and increase its nutritional value. Compared with natural fermentation, the use of specific microorganisms for fermentation can be used to determine the direction of fermentation. Therefore, in order to better explore the effect of bacterial community structure on the quality of sugarcane juice naturally fermented and inoculated with different lactic acid bacteria in the fermentation process, the most suitable method for sugarcane juice fermentation was found, which provided a theoretical basis for the safe production of fermented sugarcane juice. In this experiment, the sugarcane juice was treated differently and divided into four groups: natural fermentation, fermentation with Lactobacillus HNK10, fermentation with Lactococcus HNK21, and HNK10 + HNK21 compound fermentation. The changes in bacterial community structure of different treatments of sugarcane juice during fermentation were analyzed by high-throughput sequencing technology, and the quality change of different treatments of sugarcane juice during fermentation was analyzed by high-performance liquid chromatography, and the change in its bacteriostatic ability was explored. The results showed that after the sugarcane juice treated with Lactobacillus HNK10 was fermented at 37 °C for 48 h, the final fermented sugarcane juice had a large abundance of lactic acid bacteria and high-quality and strong antibacterial activity. Conclusions: changes in the bacterial community structure during the fermentation of sugarcane juice affect the formation of organic acids and the change of bacteriostatic ability and directly determine the quality and shelf life of fermented sugarcane juice.

The intestine of animals is a complex micro-ecosystem containing a large number of microbiomes, which is essential for the host’s health development. The Hainan black goat with good resistance and adaptability is a unique species in Hainan, China. These unique physiological characteristics are inseparable from their intestinal microbiota. In this study, high-throughput sequencing was used to investigate bacterial communities in different segments of the intestinal tract of Hainan black goat. The results showed that the indices of Chao1 and ACE in the cecum and colon were significantly greater than those in the ileum (p = 0.007, 0.018). According to PCoA, the intestinal flora composition of the cecum and colon is almost equivalent. In contexts of the phylum, Firmicutes, Bacteroidota, and Pseudomonadota were the dominant phyla in the gut of the Hainan black goat. While in context of the genus, the dominant groups in the gut of black goats mainly include Ruminococcaceae_UCG-005, Bacteroides, Paeniclostridium, Christensenellaceae_R-7_group, Rikenellaceae_RC9_gut_group, and Eubacterium coprostanoligenes _group, Prevotella_1, they have different proportions in different intestinal segments. The gut microbiota of Hainan black goat is mainly Firmicutes, Bacteroidota, and Pseudomonadota. Influenced by the intestinal location where they colonize, the large intestine has a more complex intestinal flora than the small intestine. In contrast, there are only minor differences between the caecum and the colon in the large intestine.