湛江硇洲岛海葵相关可培养细菌系统发育多样性

Phylogenetic diversity of cultivable bacteria associated with a sea anemone from coast of the Naozhou island in Zhanjiang, China

摘要:

【目的】了解湛江硇洲岛海葵样品中相关可培养细菌的多样性。【方法】运用纯培养法和基于16S rRNA基因序列的系统发育分析对样品中可培养细菌多样性进行研究。【结果】用补充0～2.0 mol/L NaCl 的MA、ISP 2、NA、SWA和HAA培养基从海葵样品中分离到126株细菌，通过形态观察和部分生理生化实验去冗余，选取42株具有代表性的菌株进行基于16S rRNA基因序列的系统发育多样性分析。结果表明，42个分离菌株可分为25个物种，属于3个大的系统发育类群(Firmicutes，Gamma-Proteobacteria，Actinobacteria)、11个科、18个属。多数菌株属于Firmicutes门（17株，40.5％）和Gamma-Proteobacteria亚门（14株，33.3％）。这些分离菌株中，至少有6个菌株可能代表6个不同属的6个新物种：JSM 071004、JSM 071068、JSM 071073、JSM 072002、JSM 073008和JSM073097分别代表Bacillus、Halobacillus、Piscibacillus、Pontibacillus、Alteromonas和Nocardiopsis属的新物种。【结论】从以上结果可以看出，湛江硇洲岛海葵中存在较为丰富的微生物物种多样性和系统发育多样性，并且潜藏着较多的新的微生物类群（物种）。

Abstract:

[Objective] To understand the diversity of cultivable bacteria isolated from a sea anemone collected from the coastal water of the Naozhou island in the Leizhou Bay on South China Sea. [Methods] Bacteria were isolated from a sea anemone by using conventional culture-dependent method and investigated by using phylogenetic analysis based on 16S rRNA gene sequence comparisons. [Results] We isolated 126 bacteria strains from the sample on marine agar 2216 (Difco), International Streotomyces Project medium 2 agar, nutrient agar, sea water agar and humic acid agar supplemented with 0–2 mol/L NaCl. Based on partial morphological, physiological and biochemical characteristics, we selected 42 strains for molecular systematic study based on 16S rRNA gene sequences. Our results showed that 42 isolates were members of eighteen genera (Alteromonas, Bacillus, Brachybacterium, Brevibacterium, Halobacillus, Halomonas, Nocardiopsis, Oceanobacillus, Piscibacillus, Planococcus, Pontibacillus, Pseudoalteromonas, Pseudonocardia, Salinicoccus, Salinivibrio, Staphylococcus, Vibrio, Virgibacillus) of eleven families (Alteromonadaceae, Bacillaceae, Brevibacteriaceae, Dermabacteraceae, Halomonadaceae, Planococcaceae, Pseudoalteromonadaceae, Pseudonocardiaceae, Nocardiopsaceae, Staphylococcaceae, Vibrionaceae) in three major phylogenetic groups (Actinobacteria, Firmicutes, Gamma-Proteobacteria). The most abundant and diverse isolates were within the phylum Firmicutes (40.5 %) and the subphylum Gamma-Proteobacteria (33.3 %). The phylogenetic distance matrix results suggested that, out of 42 isolates, 37 were different strains of 19 known species, and that at least 6 strains represented 6 new species within 6 characterized genera. [Conclusion] The results presented above showed that there were abundant species diversity and phylogenetic diversity of bacteria isolated from the sea anemone.