茅尾海无瓣海桑内生细菌多样性及其细胞毒活性

Diversity and cytotoxic activity of endophytic bacteria isolated from Sonneratia apetala of Maowei Sea

摘要:

[目的] 对无瓣海桑各组织器官内生细菌的分布特征、物种多样性及细胞毒活性进行分析。[方法] 采用稀释涂布法分析无瓣海桑内生细菌的菌落形态及分布。利用16S rRNA基因序列进行系统发育分析,探讨无瓣海桑内生细菌的物种多样性。利用MTT法测试内生细菌培养液的乙酸乙酯提取物细胞毒活性。[结果] 从各组织器官中分离出内生细菌38株,隶属12科21属(其中5属未定科),内生细菌数量和群落结构组成存在明显的组织特异性。在分离的菌株中,有5株菌与已有细菌物种典型菌株的全长16S rRNA基因相似性低于97%,代表着潜在新属或新种。5株内生细菌(R74、R71、S92、S85、S84)具有较强的细胞毒活性。[结论] 无瓣海桑中可培养内生细菌的物种多样性丰富,潜藏较丰富的新物种资源,且含有较为丰富的活性菌株。

Abstract:

[Objective] The purpose of this study was to study the distribution, diversity and cytotoxic activity of endophytic bacteria of Sonneratia apetala collected from Maowei Sea, Qinzhou city. [Methods] The 16S rRNA gene sequencing and MTT were used to explore the diversity and cytotoxic activity of endophytic bacteria isolated from different organs and tissues of Sonneratia apetala. [Results] Total of 38 isolates were obtained. The result of diversity analysis showed that these isolates could be phylogenetically classified into 21 genera and 12 families, based on their 16S rRNA gene sequencing. Of them 5 were potential new genera or new genus. Five strains (R74, R71, S92, S85 and S84) had cytotoxic activity against human liver carcinoma Hep G2 cell line. [Conclusion] Endophytic bacteria of Sonneratia apetala are genetically diverse and most of them have abundant new bioactivities.