Species-specific structural and functional diversity of bacterial communities in lichen symbioses
Species-specific structural and functional diversity of bacterial communities in lichen symbioses
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DOI：
10.1038/ismej.2009.63
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发表时间：
2009-09-01
期刊：
影响因子：
11
通讯作者：
Berg, Gabriele
中科院分区：
文献类型：
--
作者：
Grube, Martin;Cardinale, Massimiliano;Berg, Gabriele
地衣通常被认为是真菌和绿色藻类或蓝藻之间的互惠共生。这些伙伴关系允许光暴露和长寿命的联合结构。地衣的独特组织为微生物群落提供了尚未开发的环境。为了研究地衣相关的细菌群落，我们分析样品，通过多相的方法，从三个地衣物种（枝状石蕊，多托蜡蚧和Umbilicaria圆柱）从高山环境。我们的研究结果表明，细菌可以在真菌表面形成高度结构化的生物膜样组合，并达到相当高的丰度，每克鲜重高达108个细胞。荧光原位杂交揭示了α变形菌的优势。利用通用引物和组特异性引物进行PCR-单链构象多态性分析的微生物指纹显示每个地衣物种的不同模式。可培养菌株的表征和总馏分中存在的功能基因表明相关细菌参与营养循环。编码固氮酶还原酶的普遍存在的nifH基因显示出高多样性，并且被分配给α变形菌门和厚壁菌门，例如类芽孢杆菌。主要属于不动杆菌属、芽孢杆菌属、伯克霍尔德氏菌属、甲基杆菌属和类芽孢杆菌属的可培养菌株显示出裂解（几丁质分解、葡聚糖分解和蛋白水解）活性、激素产生（吲哚-3-乙酸）以及磷酸盐动员和对其他微生物的拮抗活性。地衣的传统概念必须扩展到考虑多种细菌伴侣。The ISME Journal（2009）3，1105-1115; doi：10.1038/ismej.2009.63; 2009年6月25日在线发表
Lichens are generally considered as mutualisms between fungi and green algae or cyanobacteria. These partnerships allow light-exposed and long-living joint structures. The unique organization of lichens provides still unexplored environments for microbial communities. To study lichen-associated bacterial communities, we analyze samples, by a polyphasic approach, from three lichen species (Cladonia arbuscula, Lecanora polytropa and Umbilicaria cylindrica) from alpine environments. Our results indicate that bacteria can form highly structured, biofilm-like assemblages on fungal surfaces and reach considerable abundances of up to 108 cells per gram fresh weight. Fluorescence in situ hybridization reveals the predominance of Alphaproteobacteria. Microbial fingerprints performed by PCR-single-strand conformation polymorphism analysis using universal and group-specific primers show distinct patterns for each lichen species. Characterization of cultivable strains and presence of functional genes in the total fraction suggest the involvement of associated bacteria in nutrient cycling. Ubiquitous nifH genes, which encode the nitrogenase reductase, show a high diversity and are assigned to Alphaproteobacteria and Firmicutes, for example, Paenibacillus. Cultivable strains mainly belonging to the genera Acinetobacter, Bacillus, Burkholderia, Methylobacterium and Paenibacillus show lytic (chitinolytic, glucanolytic, and proteolytic) activities, hormone production (indole-3-acetic acid) as well as phosphate mobilization and antagonistic activity toward other microorganisms. The traditional concept of lichens has to be expanded to consider multiple bacterial partners. The ISME Journal (2009) 3, 1105-1115; doi:10.1038/ismej.2009.63; published online 25 June 2009