第六次北极科学考察海洋沉积物可培养细菌的多样性分析

Biodiversity analysis of cultivable bacteria isolated from marine sediments collected during 6th Arctic Expedition

摘要:

【目的】研究北极海洋沉积物可培养细菌的菌种资源多样性。【方法】采用海水Zobell2216E 培养基和涂布平板法对第六次北极科学考察获得的海洋沉积物开展细菌分离培养,通过16S rRNA 基因系统发育分析了解可培养细菌的多样性。【结果】根据菌落形态特征,从40 个站位的北极海洋沉积物样品中共分离并获得16S rRNA 基因有效序列的细菌达445 株;基于16S rRNA 基因的相似性分析与系统发育研究结果表明,分离获得的细菌分属于细菌域的4 个门、6 个纲、13 个目、28 个科、49 个属、91 个种,其中γ-Proteobacteria 占大多数;有12 株与模式菌株的16S rRNA 基因序列相似性小于97%,可能代表了6 个潜在的细菌新物种;此次获得的细菌种类组成与以往第五次北极科考获得的相比,在属水平上差异较大。【结论】北极海洋沉积物中存在着丰富的微生物菌种资源,具有很多新型微生物仍未被发现,是亟待开发的微生物资源宝库。

Abstract:

[Objective] Investigating the diversity of the cultivable bacteria in Arctic Ocean sediments. [Methods] Culturable bacteria were isolated from marine sediments collected during the 6^th Chinese National Arctic Expedition (Arc6) by marine Zobell 2216E medium and spread plate method. Subsequently, 16S rRNA gene sequence similarity analysis and phylogenetic analysis were performed. [Results] A total of 445 strains were isolated from 40 sediments samples. According to the results of 16S rRNA gene sequence similarity as well as phylogenetic analysis, the isolates belong to 4 phyla, 6 classes, 13 orders, 28 families, 49 genera and 91 species. Twelve isolates having 16S rRNA gene similarity less than 97% with the closest type strain were grouped into 6 independent clusters, implying that these isolates might be six novel species. Our study also indicated that the genus composition of the strains from 6^th Arctic Expedition were strikingly different with that from 5^th Arctic Expedition (Arc5). [Conclusion] There are abundant microbial resources and many novel microbes in Arctic Ocean sediments, and it is to be developed in the treasure house of microorganisms.