海绵Pachychalina sp.体内细菌多样性的研究

通过非分离培养分析方法，直接从海绵体内提取细菌总DNA。以样品总DNA为模板进行PCR扩增获得细菌16S rDNA。用16S rDNA限制性酶切片段长度多态性(ARDRA)和测序方法对南海湛江海域海绵Pachychalina sp．体内的细菌多样性进行了研究。在细菌16S rDNA的ARDRA图谱中，大多数克隆的酶切带谱间存在差异；随机挑选22个克隆进行测序得到它们的16S rDNA部分序列，大部分序列属于γ-proteobacterium和α-proteobacterium，但有少数克隆序列与RDP数据库中收录的16S rDNA序列间的相似性极小，不参与系统发育树的构建。研究结果表明海绵Pachychalina sp.体内细菌组成具有丰富的多样性。

Phylogenetic Diversity of Bacterium Associated with the Sponge Pachychalina sp.

With culture independent approach, microbial DNA was directly extracted from Pachychalina sp.. Using the microbial DNA as template, bacterial 16S rDNAs were amplified by PCR. Amplified products were cloned, sequenced and secondarily amplified by PCR. Then the secondarily amplified products were purified to be further characterized by termed ARDRA(amplified rDNA restriction analysis,ARDRA).According to the enzyme restriction mapping, the apparent difference among them were disclosed. Twenty two different cloned partial sequences were acquired and most of them were related to proteobacter. In the phylogenetic tree, some clones came under alpha proteobacterium and some clones representing some novel groups, belonged to gamma proteobacterium. Others aligned with a similarity value of 0 11 in the RDP database could not be found in the phylogenetic tree. Result shows prolific bacterial diversity of marine sponge Pachychalina sp..