Microbial Community Structure and Activity Linked to Contrasting Biogeochemical Gradients in Bog and Fen Environments of the Glacial Lake Agassiz Peatland
Microbial Community Structure and Activity Linked to Contrasting Biogeochemical Gradients in Bog and Fen Environments of the Glacial Lake Agassiz Peatland
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DOI：
10.1128/aem.01750-12
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发表时间：
2012-10-01
影响因子：
4.4
通讯作者：
Kostka, J. E.
中科院分区：
文献类型：
--
作者：
Lin, X.;Green, S.;Kostka, J. E.
在明尼苏达州西北部的冰川湖阿加西泥炭地的沼泽和沼泽地的微生物群落的丰度，组成和活动进行了调查。这些网站的对比溶解有机物（DOM）的反应性和存在或不存在的地下水输入。利用焦磷酸测序和系统发育标记基因的克隆文库构建来表征微生物群落组成。微生物的分布格局与pH值，溶解性有机碳和氮的浓度，C/N比，DOM的光学性质，漆酶和过氧化物酶的活性。沼泽中细菌和古细菌的丰富度和rRNA基因丰度平均比沼泽高2倍以上，这与沼泽中较高的pH值、不稳定的DOM含量和增强的酶活性一致。真菌相当于总原核生物的基因丰度的平均1.4%，通过定量PCR测定。结果显示，细菌和真菌群落之间的统计学上不同的空间格局。真菌的分布并没有随pH值和DOM的光学特性，垂直分层，子囊菌门和担子菌门的流行率近表面和更高的代表性接合菌门在地下。相比之下，细菌群落组成在很大程度上不同的环境，沼泽占主导地位的酸杆菌（61%的总序列），而厚壁菌门（52%）占主导地位的沼泽。乙酸碎屑甲烷菌在沼泽中表现出更高的相对丰度，在不同的氢营养产甲烷菌在沼泽中的优势。这是第一个定量和组成分析的三个微生物领域的泥炭地，并表明，微生物的丰度，多样性和活性平行的沼泽和沼泽地之间的环境变量的显着差异。
The abundances, compositions, and activities of microbial communities were investigated at bog and fen sites in the Glacial Lake Agassiz Peatland of northwestern Minnesota. These sites contrast in the reactivity of dissolved organic matter (DOM) and the presence or absence of groundwater inputs. Microbial community composition was characterized using pyrosequencing and clone library construction of phylogenetic marker genes. Microbial distribution patterns were linked to pH, concentrations of dissolved organic carbon and nitrogen, C/N ratios, optical properties of DOM, and activities of laccase and peroxidase enzymes. Both bacterial and archaeal richness and rRNA gene abundance were >2 times higher on average in the fen than in the bog, in agreement with a higher pH, labile DOM content, and enhanced enzyme activities in the fen. Fungi were equivalent to an average of 1.4% of total prokaryotes in gene abundance assayed by quantitative PCR. Results revealed statistically distinct spatial patterns between bacterial and fungal communities. Fungal distribution did not covary with pH and DOM optical properties and was vertically stratified, with a prevalence of Ascomycota and Basidiomycota near the surface and much higher representation of Zygomycota in the subsurface. In contrast, bacterial community composition largely varied between environments, with the bog dominated by Acidobacteria (61% of total sequences), while the Firmicutes (52%) dominated in the fen. Acetoclastic Methanosarcinales showed a much higher relative abundance in the bog, in contrast to the dominance of diverse hydrogenotrophic methanogens in the fen. This is the first quantitative and compositional analysis of three microbial domains in peatlands and demonstrates that the microbial abundance, diversity, and activity parallel with the pronounced differences in environmental variables between bog and fen sites.