Occurrence and potential activity of denitrifiers and methanogens in groundwater at 140 m depth in Pliocene diatomaceous mudstone of northern Japan.
Occurrence and potential activity of denitrifiers and methanogens in groundwater at 140 m depth in Pliocene diatomaceous mudstone of northern Japan.
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DOI：
10.1111/1574-6941.12179
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发表时间：
2013-12
影响因子：
4.2
通讯作者：
Chie Katsuyama;Hiroaki Nashimoto;K. Nagaosa;T. Ishibashi;Kazuki Furuta;T. Kinoshita;H. Yoshikawa;K. Aoki;T. Asano;Yoshito Sasaki;R. Sohrin;D. Komatsu;U. Tsunogai;Hiroyuki Kimura;Y. Suwa;Kenji Kato
中科院分区：
文献类型：
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作者：
Chie Katsuyama;Hiroaki Nashimoto;K. Nagaosa;T. Ishibashi;Kazuki Furuta;T. Kinoshita;H. Yoshikawa;K. Aoki;T. Asano;Yoshito Sasaki;R. Sohrin;D. Komatsu;U. Tsunogai;Hiroyuki Kimura;Y. Suwa;Kenji Kato
厌氧微生物活动对地下环境有重要影响。我们调查了缺氧地下水中的反硝化和甲烷生成在两个钻孔钻在沉积地质环境中，氧化还原电位波动的深度为140米。在厌氧条件下，使用（15）N示踪剂在两个钻孔中测量的平均最大潜在反硝化速率为0.060和0.085 nmol（30）N2 mL（-1）h（-1）。从原位样品中获得的推断的NirS氨基酸序列与属于α-、β-和γ-变形菌门以及厚壁菌门的分离物的那些相似（72-100%相似性）。基于nirS基因，相同的操作分类单元主导每个钻孔的孵育样品。通过16 S rRNA基因分析检测到产甲烷候选物，但使用功能性产甲烷基因mcrA的引物未检测到序列。虽然稳定同位素特征表明，一些溶解的甲烷是生物来源的，没有甲烷生产的潜力是明显的，在孵育过程中。地下水在140米深处不含氧，有一个Eh范围为-144至6.8 mV，并被发现是一个潜在的反硝化领域。
Anaerobic microbial activity has a major influence on the subsurface environment. We investigated the denitrification and methanogenesis in anoxic groundwater at a depth of 140 m in two boreholes drilled in a sedimentary geological setting, where the redox potential fluctuated. The average maximum potential denitrification rates, measured under anaerobic conditions in the two boreholes using an (15) N tracer, were 0.060 and 0.085 nmol (30) N2 mL(-1) h(-1) . The deduced NirS amino acid sequences obtained from in situ samples were similar to those of isolates belonging to the α-, β-, and γ-Proteobacteria, and the Firmicutes (72-100% similarity). Based on the nirS gene, the same operational taxonomic unit dominated incubated samples from each borehole. Methanogenesis candidates were detected by 16S rRNA gene analysis, but no sequence was detected using primers for the functional methanogenesis gene mcrA. Although the stable isotope signatures suggested that some of the dissolved methane was of biogenic origin, no potential for methane production was evident during the incubations. The groundwater at 140 m depth did not contain oxygen, had an Eh ranging from -144 to 6.8 mV, and was found to be a potential field for denitrification.