Archaeal community structure and pathway of methane formation on rice roots
Archaeal community structure and pathway of methane formation on rice roots
复制标题
DOI：
10.1007/s00248-003-2014-7
复制
发表时间：
2004-01-01
影响因子：
3.6
通讯作者：
Conrad, R
中科院分区：
文献类型：
--
作者：
Chin, KJ;Lueders, T;Conrad, R
通过16 SrRNA和甲基辅酶M还原酶（mcrA）基因的扩增、测序和系统发育分析，研究了缺氧培养水稻根系产甲烷菌的群落结构。这两个基因都证明了甲烷微菌科、甲烷杆菌科、甲烷小球藻科、甲烷小球藻科和水稻簇I（一个未培养的产甲烷谱系）的存在。甲烷形成的途径，确定从C-13-同位素的签名产生的甲烷，二氧化碳和乙酸。培养条件和培养时间明显影响产甲烷菌群落结构和甲烷生成途径。甲烷最初仅由CO2的还原产生，导致乙酸盐的毫摩尔浓度的积累。同时，乙酸裂解产甲烷菌（Methanoclycinaceae，Methanosaetaceae）的相对丰度，16 S rRNA基因的T-RFLP分析确定，在CH 4生产的初始阶段低。然而，后来，乙酸盐被转化为CH 4，使得约40%的所产生的CH 4源自乙酸盐。最引人注目的是观察到的甲烷八叠球菌属的种群的相对增加。(but不属于甲烷菌属）在乙酸盐浓度开始降低之前短暂地。醋酸破产甲烷和甲烷八叠球菌种群被抑制高浓度的磷酸盐，根据不同的缓冲系统的应用程序中观察到。我们的结果表明，在复杂的环境中，微生物群落结构和功能的平行变化，即，甲烷八叠球菌（Methanosarcina spp.）当高乙酸盐浓度变得可用时。
The community structure of methanogenic Archaea on anoxically incubated rice roots was investigated by amplification, sequencing, and phylogenetic analysis of 16S rRNA and methyl-coenzyme M reductase (mcrA) genes. Both genes demonstrated the presence of Methanomicrobiaceae, Methanobacteriaceae, Methanosarcinaceae, Methanosaetaceae, and Rice cluster I, an uncultured methanogenic lineage. The pathway of CH4 formation was determined from the C-13-isotopic signatures of the produced CH4, CO2 and acetate. Conditions and duration of incubation clearly affected the methanogenic community structure and the pathway of CH4 formation. Methane was initially produced from reduction of CO2 exclusively, resulting in accumulation of millimolar concentrations of acetate. Simultaneously, the relative abundance of the acetoclastic methanogens (Methanosarcinaceae, Methanosaetaceae), as determined by T-RFLP analysis of 16S rRNA genes, was low during the initial phase of CH4 production. Later on, however, acetate was converted to CH4 so that about 40% of the produced CH4 originated from acetate. Most striking was the observed relative increase of a population of Methanosarcina spp. (but not of Methanosaeta spp.) briefly before acetate concentrations started to decrease. Both acetoclastic methanogenesis and Methanosarcina populations were suppressed by high phosphate concentrations, as observed under application of different buffer systems. Our results demonstrate the parallel change of microbial community structure and function in a complex environment, i.e., the increase of acetoclastic Methanosarcina spp. when high acetate concentrations become available.