Time distribution of culturable bacteria and pathogens in the Western South China Sea by using five kinds of culture methods

Abstract Marine bacteria occupy an important position in the biogeochemical cycle. The study of marine bacteria can provide basis for understanding the ecosystem, microbial evolution and medical health utilization. However, most marine bacteria can not be cultured till now, and the research on culturable bacteria is significant.Wenchang sea area is located in the west of the South China Sea, representing a tropical marine biodiversity of the world. Typhoons often occur in this area after autumn. We assume that the difficulty of culturing bacteria from the ocean is different at different times. Results This study collected seawater at six different sites in four different quarters and cultured marine bacteria using five kinds of culture media. Then, bacteria were identified by 16S rDNA full-length sequence analysis. For the full year, 1151 strains of identifiable bacteria were isolated, which could be identified as 4 phyla, 9 classes, 20 orders, 38 families, 66 genera, and 213 species. Klebsiella, Exiguobacterium, Proteus, and Escherichia are the dominant genera, accounting for 9.64%, 8.77%, 6.52%, and 6.52% respectively. Klebsiella pneumoniae, Proteus mirabilis, Exiguobacterium indicum, and Escherichia coli are the dominant species, accounting for 7.99%, 6.34%, 4.69%, and 4.52% respectively. This study also found season-specific bacteria and pathogens appearing throughout the year. Conclusions It first revealed the time distribution of culturable bacteria and pathogens from the Wenchang coastline of Hainan Island, The South China Sea, and broadened understanding of the western Pacific Ocean microbes.