Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens
Metagenomic and metaproteomic insights into bacterial communities in leaf-cutter ant fungus gardens
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DOI：
10.1038/ismej.2012.10
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发表时间：
2012-09-01
期刊：
影响因子：
11
通讯作者：
Currie, Cameron R.
中科院分区：
文献类型：
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作者：
Aylward, Frank O.;Burnum, Kristin E.;Currie, Cameron R.
草食动物主要通过利用微生物的代谢活动来获得储存在植物生物量中的营养物质。ATTA属的切叶蚂蚁就是一个标志性的例子；这些占主导地位的新热带草食动物以大量新鲜植物饲料为原料培育共生真菌花园。真菌园作为蚂蚁的外消化系统，方便了数以百万计的劳动者的生产和生计。利用总基因组学和总蛋白质组学技术，我们研究了两种真菌园的细菌多样性和生理潜力。我们对超过1.2GbP的群落元基因组序列和三个16S焦标文库的分析表明，除了拥有优势真菌作物外，这些生态系统还包含丰富的肠杆菌科种群，包括肠杆菌属、泛细菌属、克雷伯氏菌属、柠檬酸杆菌属和大肠杆菌属。我们发现，这些细菌群落拥有与木质纤维素降解相关的基因和不同的生物合成途径，表明它们通过将蚂蚁的低氮饲料转化为B-维生素、氨基酸和其他细胞成分，在营养循环中发挥作用。我们的代谢蛋白质组学分析证实，在野外采集和实验室饲养的菌落中都产生了细菌糖基水解酶和具有假定生物合成功能的蛋白质。这些结果与真菌花园是专门的真菌-细菌群落的假设是一致的，它们将植物材料转化为蚂蚁宿主的能量。结合最近对脊椎动物微生物共生体的研究，我们的工作强调了微生物群落在食草性后生动物生态和进化中的重要性。ISME期刊(2012年)6,1688-1701年；doi：10.1038/ismej.2012.10；在线发布2012年3月1日主题类别：微生物生态学中的整合基因组学和后基因组学方法
Herbivores gain access to nutrients stored in plant biomass largely by harnessing the metabolic activities of microbes. Leaf-cutter ants of the genus Atta are a hallmark example; these dominant neotropical herbivores cultivate symbiotic fungus gardens on large quantities of fresh plant forage. As the external digestive system of the ants, fungus gardens facilitate the production and sustenance of millions of workers. Using metagenomic and metaproteomic techniques, we characterize the bacterial diversity and physiological potential of fungus gardens from two species of Atta. Our analysis of over 1.2 Gbp of community metagenomic sequence and three 16S pyrotag libraries reveals that in addition to harboring the dominant fungal crop, these ecosystems contain abundant populations of Enterobacteriaceae, including the genera Enterobacter, Pantoea, Klebsiella, Citrobacter and Escherichia. We show that these bacterial communities possess genes associated with lignocellulose degradation and diverse biosynthetic pathways, suggesting that they play a role in nutrient cycling by converting the nitrogen-poor forage of the ants into B-vitamins, amino acids and other cellular components. Our metaproteomic analysis confirms that bacterial glycosyl hydrolases and proteins with putative biosynthetic functions are produced in both field-collected and laboratory-reared colonies. These results are consistent with the hypothesis that fungus gardens are specialized fungus-bacteria communities that convert plant material into energy for their ant hosts. Together with recent investigations into the microbial symbionts of vertebrates, our work underscores the importance of microbial communities in the ecology and evolution of herbivorous metazoans. The ISME Journal (2012) 6, 1688-1701; doi:10.1038/ismej.2012.10; published online 1 March 2012 Subject Category: integrated genomics and post-genomics approaches in microbial ecology