Putkinen Anuliina, Juottonen Heli, Juutinen Sari, Tuittila Eeva-Stiina, Fritze Hannu, Yrjälä Kim
Department of Biological and Environmental Sciences, General Microbiology, University of Helsinki, Helsinki, Finland.
FEMS Microbiol Ecol. 2009 Oct;70(1):87-98. doi: 10.1111/j.1574-6941.2009.00738.x. Epub 2009 Jul 10.
Northern peatlands play a major role in the global carbon cycle as sinks for CO(2) and as sources of CH(4). These diverse ecosystems develop through accumulation of partially decomposed plant material as peat. With increasing depth, peat becomes more and more recalcitrant due to its longer exposure to decomposing processes. Compared with surface peat, deeper peat sediments remain microbiologically poorly described. We detected active archaeal communities even in the deep bottom layers (-220/-280 cm) of two Finnish fen-type peatlands by 16S rRNA-based terminal restriction fragment length polymorphism analysis. In the sediments of the northern study site, all detected archaea were methanogens with Rice Cluster II (RC-II) and Methanosaetaceae as major groups. In southern peatland, Crenarchaeota of a rare unidentified cluster were present together with mainly RC-II methanogens. RNA profiles showed a larger archaeal diversity than DNA-based community profiles, suggesting that small but active populations were better visualized with rRNA. In addition, potential methane production measurements indicated methanogenic activity throughout the vertical peat profiles.
北方泥炭地作为二氧化碳的汇和甲烷的源，在全球碳循环中发挥着重要作用。这些多样的生态系统通过部分分解的植物物质积累形成泥炭而发展起来。随着深度增加，泥炭因暴露于分解过程的时间更长而变得越来越难分解。与表层泥炭相比，深层泥炭沉积物的微生物学特征仍描述较少。通过基于16S rRNA的末端限制性片段长度多态性分析，我们在芬兰两个富营养型泥炭地的深层底部（-220/-280厘米）检测到了活跃的古菌群落。在北方研究地点的沉积物中，所有检测到的古菌都是产甲烷菌，主要类群为水稻集群II（RC-II）和甲烷八叠球菌科。在南方泥炭地，一个罕见的未鉴定集群的泉古菌与主要的RC-II产甲烷菌共同存在。RNA图谱显示出比基于DNA的群落图谱更大的古菌多样性，这表明用rRNA能更好地观察到数量虽少但活跃的种群。此外，潜在甲烷产量测量表明，在整个泥炭垂直剖面中都存在产甲烷活性。
