Microbial Community Structure and Function Succession of Puffer Fish (Takifugu obscurus) During Refrigeration

Objective: To reveal the microbial community and its function succession principles of puffer fish (Takifugu obscurus), and to identify the dominant microbial genera on puffer fish during refrigerated storage. Methods: High-throughput sequencing was employed to investigate the microbial composition of puffer fish during refrigeration (4 ℃, 8 d), the community function was predicted by Tax4fun2, and the total volatile basic-nitrogen (TVB-N), pH and organoleptic values of puffer fish were measured as well. Results: The high-throughput sequencing demonstrated that during refrigeration the bacterial community of puffer fish succeed significantly, which were mainly composed of genera Acinetobacter, Lactobacillus, Aeromonas and Pseudomonas at the initial stage, while at the last stage composed almost of genera Pseudomonas (>91.7%), which was considered as the dominant genera on puffer fish. The α-diversity index of the community was higher at initial stage, while decreased during the storage. The microbial community function prediction results showed that the relative abundance of the amino-acid metabolism pathway and the cellular communication pathway increased at the last stage of the storage. As for the physicochemical properties, TVB-N, pH and total microbial counts increased while sensory scores decreased during the storage. Conclusion: The microbial community and its functional profile changed significantly during refrigeration, Pseudomonas was the dominant genera of puffer fish, and the above conclusion would provide theoretic guidelines for developing novel preserving technology for puffer fish.