Isolation and identification of the symbiotic bacteria of Homoiodoris japonica and screen of bioactive metabolite producing bacteria

Abstract:

[Objective] The present work aims to study the amounts and species of cultivable microbes and bioactive metabolite producing bacteria from a marine invertebrate collected in Shenzhen. [Methods] We dissected the invertebrate into five parts to isolated bacteria by R2A plate and identified them through the 16S rRNA sequence. Then use the culture broth and supernatant to screen the activity of degrading quorum-sensing signal molecules and anti-biofilm activity. [Results] A total of 216 strains of bacteria were isolated from the invertebrate, belonging to 87 species and 54 genera, and 16 strains were suspected to be new bacteria. Distributed in the phylum Proteobacteria (126 strains), Bacteroidetes (44 strains), Firmicutes (34 strains), Actinobacteria (10 strains), and Planctomycetes (1 strain). The number and species of bacteria in the eggs of the invertebrate were the most diverse. Twenty-eight strains were screened to degrade quorum-sensing signal molecules, and eight strains showed anti-biofilm activity. [Conclusion] It is the first report that the marine invertebrate Homoiodoris japonica-associated bacteria contains were abundant and diverse, including potential new species of bacteria and natural product resources, which may provide a research basis for future research on the Homoiodoris japonica-associated microbes.