Lee On On, Wong Yue Him, Qian Pei-Yuan
Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, China.
Appl Environ Microbiol. 2009 Jun;75(11):3513-21. doi: 10.1128/AEM.00002-09. Epub 2009 Apr 10.
This study attempted to assess whether conspecific or congeneric sponges around San Juan Island, Washington, harbor specific bacterial communities. We used a combination of culture-independent DNA fingerprinting techniques (terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis [DGGE]) and culture-dependent approaches. The results indicated that the bacterial communities in the water column consisted of more diverse bacterial ribotypes than and were drastically different from those associated with the sponges. High levels of similarity in sponge-associated bacterial communities were found only in Myxilla incrustans and Haliclona rufescens, while the bacterial communities in Halichondria panicea varied substantially among sites. Certain terminal restriction fragments or DGGE bands were consistently obtained for different individuals of M. incrustans and H. rufescens collected from different sites, suggesting that there are stable or even specific associations of certain bacteria in these two sponges. However, no specific bacterial associations were found for H. panicea or for any one sponge genus. Sequencing of nine DGGE bands resulted in recovery of seven sequences that best matched the sequences of uncultured Proteobacteria. Three of these sequences fell into the sponge-specific sequence clusters previously suggested. An uncultured alphaproteobacterium and a culturable Bacillus sp. were found exclusively in all M. incrustans sponges, while an uncultured gammaproteobacterium was unique to H. rufescens. In contrast, the cultivation approach indicated that sponges contained a large proportion of Firmicutes, especially Bacillus, and revealed large variations in the culturable bacterial communities associated with congeneric and conspecific sponges. This study revealed sponge species-specific but not genus- or site-specific associations between sponges and bacterial communities and emphasized the importance of using a combination of techniques for studying microbial communities.
本研究试图评估华盛顿圣胡安岛周围的同种或同属海绵是否含有特定的细菌群落。我们结合了非培养依赖型DNA指纹技术（末端限制性片段长度多态性和变性梯度凝胶电泳[DGGE]）和培养依赖型方法。结果表明，水柱中的细菌群落由比与海绵相关的细菌核糖型更多样化的细菌核糖型组成，且与后者有很大差异。仅在包被粘海绵和红拟厚皮海绵中发现海绵相关细菌群落具有高度相似性，而扇海绵中的细菌群落在不同地点之间有很大差异。从不同地点采集的包被粘海绵和红拟厚皮海绵的不同个体始终能获得某些末端限制性片段或DGGE条带，这表明这两种海绵中存在某些细菌的稳定甚至特定关联。然而，在扇海绵或任何一个海绵属中未发现特定的细菌关联。对9条DGGE条带进行测序后，获得了7条与未培养变形菌序列最匹配的序列。其中3条序列属于先前提出的海绵特异性序列簇。一种未培养的α变形菌和一种可培养的芽孢杆菌仅在所有包被粘海绵中发现，而一种未培养的γ变形菌是红拟厚皮海绵特有的。相比之下，培养方法表明海绵中含有很大比例的厚壁菌门，尤其是芽孢杆菌，并揭示了与同属和同种海绵相关的可培养细菌群落存在很大差异。本研究揭示了海绵与细菌群落之间存在海绵物种特异性而非属特异性或地点特异性的关联，并强调了使用多种技术组合研究微生物群落的重要性。
