Li Qianqian, Wang Fengping, Chen Zhiwei, Yin Xijie, Xiao Xiang
State Key Laboratory of Microbial Metabolism, School of Life Science and Biotechnology Shanghai, P.R. China.
Front Microbiol. 2012 Aug 30;3:311. doi: 10.3389/fmicb.2012.00311. eCollection 2012.
Here the composition of total and active archaeal communities in a sediment core of Jiulong River estuary at Fujian Province, Southern China was reported. Profiles of CH(4) and SO(2-) (4) concentrations from the sediment core indicated the existence of a sulfate-methane transition zone (SMTZ) in which sulfate reduction-coupled anaerobic oxidation of methane (AOM) occurs. Accordingly, three sediment layers (16-18.5 cm, 71-73.5 cm, and 161-163.5 cm) from the 1.2 m sediment core were sectioned and named top, middle and bottom, respectively. Total DNA and RNA of each layer were extracted and used for clone libraries and sequence analysis of 16S rRNA genes, the reverse transcription (RT)-PCR products of 16S rRNA and methyl CoM reductase alpha subunit (mcrA) genes. Phylogenetic analysis indicated that archaeal communities of the three layers were dominated by the Miscellaneous Crenarchaeotal Group (MCG) whose ecological functions were still unknown. The MCG could be further divided into seven subgroups, named MCG-A, B, C, D, E, F, and G. MCG-A and MCG-G were the most active groups in the estuarine sediments. Known anaerobic methanotrophic archaea (ANMEs) were only found as minor components in these estuarine archaeal communities. This study, together with the studies of deep subsurface sediments, would be a very good start point to target and compare the specific active archaeal groups and their roles in the dark, deep subsurface sediment environments.
本文报道了中国南方福建省九龙江河口沉积物岩芯中古菌群落的总组成和活性组成。沉积物岩芯中CH₄和SO₄²⁻浓度的剖面表明存在硫酸盐-甲烷过渡带（SMTZ），其中发生了硫酸盐还原耦合的甲烷厌氧氧化（AOM）。因此，从1.2米沉积物岩芯中切取了三个沉积层（16 - 18.5厘米、71 - 73.5厘米和161 - 163.5厘米），分别命名为顶部、中部和底部。提取各层的总DNA和RNA，用于16S rRNA基因、16S rRNA逆转录（RT）-PCR产物和甲基辅酶M还原酶α亚基（mcrA）基因的克隆文库构建和序列分析。系统发育分析表明，这三个层的古菌群落以杂食泉古菌组（MCG）为主，其生态功能尚不清楚。MCG可进一步分为七个亚组，命名为MCG-A、B、C、D、E、F和G。MCG-A和MCG-G是河口沉积物中最活跃的组。已知的厌氧甲烷氧化古菌（ANMEs）在这些河口古菌群落中仅作为次要成分被发现。这项研究与深部地下沉积物的研究一起，将是一个很好的起点，用于靶向和比较特定的活性古菌组及其在黑暗、深部地下沉积物环境中的作用。
