Abstract: The aim of this study was to clarify the structural and functional characteristics of bacterial community in Apostichopus japonicus  culture ponds during freeze-thaw period. With a typical A. japonicus culture pond in northern China as the research object, we used 16S rRNA high-throughput sequencing to study the generality and specificity of structure and function of bacterial community in the water of A. japonicus culture ponds in freeze period and thaw period. The results showed that the dominant bacterial groups during freeze-thaw period were Proteobacteria, Bacteroidetes, and Actinobacteria. The specific bacterial groups in the freeze period were composed of Fusobacteria and Acidobacteria, while that in the thaw period was mainly composed of Actinobacteria. Based on the analysis of KEGG database, there were significant differences in the metabolic pathways of bacterial communities between freeze period and thaw period. The differential metabolic pathways were mainly manifested in metabolism, represented by energy metabolism, biosynthesis of other secondary metabolites, and nucleotide metabolism. There were significant differences in the structure and function of bacterial community in water of Apostichopus japonicus culture ponds during freeze period and thaw period. Our results provide a theoretical basis for fine management of A. japonicus culture ponds and healthy culture of A. japonicus.

Key words: freeze-thaw period, Apostichopus japonicus, water, bacterial community, high-throughput sequencing.