南海南沙海域沉积物中可培养微生物及其多样性分析

Diversity of bacteria isolated from the South China Sea sediments

摘要:

【目的】为了从南沙海域中分离获得微生物菌种资源，【方法】本文通过沉积物采样、可培养菌分离及16S rRNA鉴定，【结果】从22个站点的沉积物样品中获得349株细菌，分属于87个种。发现产芽孢细菌分布最广，并在10个站点的分离株中占多数；它们是Bacillus，Halobacillus，Brevibacillus，Paenibacillus，Pontibacillus和Thalassobacillus。其中芽孢杆菌（Bacillus）无论在数量上还是种类上都最多，分别属于34种，其中有8个可能的新种。此外，g-Proteobacteria是分离率较高的另一亚群；其中，假单胞菌（Pseudomonas），海杆菌（Marinobacter），食烷菌（Alcanivorax）属的细菌最多。统计还发现，在深度750~2000 m之间，低GC含量的细菌最丰富，而深度2000 m以下，分离株则全部为g-Proteobacteria。【结论】南沙沉积物可培养微生物中产芽孢细菌及 g-Proteobacteria比较丰富；其中，产芽孢细菌的多样性最高，具有进一步研究开发价值。

Abstract:

[Objective] To isolate bacteria from Nansha area of South China sea, [Methods] Sediment samples of 22 sites were used. Bacterial isolation was conducted on plates of marine medium, followed by 16S rRNA identification and phylogenetic analysis. [Results] In total 349 bacteria were obtained, belonging to 87 species. Analyses of 16S rRNA sequence showed that Bacillus and other spore-forming bacteria occupied the majority of isolates in 10 sites. Bacillus was the most abundant bacterium and of high diversity; with 34 species and 8 possible novel species. Halobacillus also occurred frequently while other spore-forming bacteria including Brevibacillus, Paenibacillus, Pontibacillus and Thalassobacillus were also found, but less occurred in this area. In addition to these low-G+C-content bacteria, γ-Proteobacteria were the second subgroup of high occurrence, among which Pseudomonas, Marinobacter and Alcanivorax were relatively abundant. Generally, isolates of 750-2000m deep mainly consist of low-G+C-content bacteria, while mainly composed of gamma-Proteobacteria when the depth is over 2000m. [Conclusion] Marine sediments of South China Sea are rich in spore-forming bacteria, which deserve further study and exploitation.