石磺海牛共附生细菌的分离和活性菌株筛选

【目的】研究深圳大鹏半岛海域石磺海牛中可培养的共附生细菌的数量和种类,并对分离获得菌株的代谢产物进行活性筛选。【方法】通过R2A平板培养、分离纯化和16SrRNA测序,分析鉴定石磺海牛中5个部位可培养细菌;使用分离菌株的菌液及发酵液上清,测定对群体感应信号分子降解的活性和抗生物膜活性。【结果】从石磺海牛中共分离到215株细菌,归属于87个种,54个属,有16株菌疑似为新菌。分离获得的菌株分布于变形菌门(Proteobacteria,126株),拟杆菌门(Bacteroidetes,44株),厚壁菌门(Firmicutes,34株),放线菌门(Actinobacteria,10株)和浮霉菌门(Planctomycetes,1株)。石磺海牛卵中的细菌数量和种类最为多样。从分离的菌株中筛选出28株菌能够降解群体感应信号分子,8株菌具有抗生物膜活性。【结论】首次报道了海洋无脊椎动物石磺海牛中具有丰富多样的可培养细菌,包含潜在的新微生物和天然产物资源,为今后研究石磺海牛共附生微生物提供了研究基础和参考。

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

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.