中国北部湾光裸方格星虫可培养微生物的分离鉴定及其活性代谢物产生菌筛选

Isolation and identification of cultivable microbes to screen bioactive metabolite producing bacteria from Sipunculus nudus in the Beibu Gulf of China

摘要:

[目的] 本研究从北部湾海域光裸方格星虫（Sipunculus nudus）肠道中分离鉴定可培养微生物，并对筛选菌株的代谢物活性进行研究，为后续开发和利用光裸方格星虫肠道微生物代谢产物提供理论支持。[方法] 通过微生物培养、菌株分离纯化和16S rRNA基因序列分析，分析鉴定湛江、北海、防城港三地光裸方格星虫肠道可培养微生物；采用透明圈法、可见分光光度法、平板打孔法等对产胞外活性代谢物的菌株进行筛选和活性分析。[结果] 中国北部湾不同海域光裸方格星虫肠道可培养微生物包括弧菌属（Vibrio）、希瓦氏菌属（Shewanella）、假交替单胞菌属（Pseudoalteromonas）、发光杆菌属（Photobacterium）和芽孢杆菌属（Bacillus）等12个细菌属。弧菌属（Vibrio）是3个地区样本共有的优势菌群。具有产胞外水解蛋白酶、壳聚糖酶、多糖以及抑菌活性等能力的菌株主要来自假交替单胞菌属（Pseudoalteromonas）、发光杆菌属（Photobacterium）和芽孢杆菌属（Bacillus）。[结论] 中国北部湾不同海域光裸方格星虫肠道可培养微生物在属的种类上存在显著性差异，且光裸方格星虫肠道菌株具有产生多种胞外活性代谢物的能力，是一种良好的海洋活性代谢物来源。

Abstract:

[Objective] The present work aims to screen cultivable microbes and bioactive metabolite producing bacteria in the gut of Sipunculus nudus from different areas of Beibu Gulf, so as to provide theoretical support for the subsequent development and utilization of gut microbial metabolites of Sipunculus nudus. [Methods] We isolated cultivable microbes from Zhanjiang, Beihai and Fangchenggang by plate and streak cultivation, and identified those microbes according to 16S rRNA gene sequence analyses. Meanwhile, we investigated the extracellular bioactive metabolites producing bacteria by transparent ring method, visible spectrophotometer and inhibition zone methods. [Results] We successfully screened 12 cultivable microbial genera from the gut of Sipunculus nudus in three Beibu Gulf regions, including Vibrio, Shewanella, Pseudomonas, Photobacterium, Bacillus. Vibrio is the dominant bacterium among the three regions. The strains producing extracellular protease, chitosanase, polysaccharide and bacteriostatic activity were mainly from Pseudomonas, Photobacterium, Bacillus. [Conclusion] There are significant differences on the bacteria genus level among the gut of Sipunculus nudus from different area of Beibu Gulf in China. Meanwhile, the cultivable symbiotic microorganisms of Sipunculus nudus can produce various extracellular active substances, which indicated that Sipunculus nudus is a good source of marine bioactive metabolites.