Abstract: In this study, metagenomics of high-throughput sequencing were used to systematically analyze the composition and diversity of microbial communities on eggs from four major egg-producing areas of China, Jilin, Anhui, Beijing and Hebei. The results showed that the bacterial community composition on the eggshell surface consisted mainly of Actinobacteria, Firmicutes and Proteobacteria. The bacterial community composition on egg samples from Jilin consisted of Actinobacteria, Firmicutes and Proteobacteria, with relative abundance of 49.12%, 31.93% and 8.41%, respectively. The bacterial community compositions on egg samples from Anhui, Beijing and Hebei were similar, consisting of Proteobacteria, Firmicutes and Proteobacteria, with Proteobacteria being the dominant phylum, and the relative abundance of Proteobacteria in the three samples was over 50%, 77.03%, 57.93% and 84.28%, respectively. In addition, the composition of microbial community at the genus level on eggs was distinct among different producing areas. The most abundant bacterial genera on eggs from Jilin were Kocuria and Brachybacterium, with relative abundance of 10.1% and 9.83%, respectively. The distribution of bacterial genera on eggs from Anhui, Beijing and Hebei was similar, with Acinetobacter being dominant, and pathogenic bacteria were found, including Staphylococcus with relative abundance of 1.20% for eggs from Anhui, Staphylococcus with relative abundance of 3.53% and Escherichia-Shigella with relative abundance of 3.15% for eggs from Beijng, and Pseudomonas with relative abundance of 16.28% for eggs from Hebei. It can be concluded that there was some difference in the composition of microbial communities at the phylum and genus level on eggs from different regions, especially in the relative abundance. A significant compositional difference in the microbial community on eggs was found between the north region and the central south region (P < 0.01), and the north region was more suitable for egg production. In order to ensure the safety of liquid egg products, egg product enterprises should select a suitable egg disinfection method according to the microbial community composition on its surface, which is of great significance to the liquid egg processing industry.

Key words: egg; high-throughput sequencing; metagenomics; microbial diversity