Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China; Department of Agricultural Resource and Environment, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China.
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Jiangsu Key Laboratory of Agricultural Meteorology, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, 210044, China; Department of Agricultural Resource and Environment, College of Applied Meteorology, Nanjing University of Information Science and Technology, Nanjing, China.
Water Res. 2017 Oct 15;123:162-172. doi: 10.1016/j.watres.2017.06.075. Epub 2017 Jun 27.
Nitrite- and nitrate-dependent anaerobic methane oxidation are mediated by the NC10 bacteria closely related to "Candidatus Methylomirabilis oxyfera" (M. oxyfera) and the ANME-2d archaea closely related to "Candidatus Methanoperedens nitroreducens" (M. nitroreducens), respectively. Here, we investigated the occurrence and activity of both M. oxyfera-like bacteria and M. nitroreducens-like archaea in the sediment of freshwater marshes in Eastern China. The presence of diverse M. oxyfera-like bacteria (>87% identity to M. oxyfera) and M. nitroreducens-like archaea (>96% identity to M. nitroreducens) was confirmed by using Illumina-based total bacterial and archaeal 16S rRNA gene sequencing, respectively. The recovered M. oxyfera-like bacterial sequences accounted for 1.6-4.3% of the total bacterial 16S rRNA pool, and M. nitroreducens-like archaeal sequences accounted for 0.2-1.8% of the total archaeal 16S rRNA pool. The detected numbers of OTUs of the 16S rRNA genes of M. oxyfera-like bacteria and M. nitroreducens-like archaea were 78 and 72, respectively, based on 3% sequence difference. Quantitative PCR showed that the 16S rRNA gene abundance of M. oxyfera-like bacteria (6.1 × 10-3.2 × 10 copies g sediment) was 2-4 orders of magnitude higher than that of M. nitroreducens-like archaea (1.4 × 10-3.2 × 10 copies g sediment). Stable isotope experiments showed that the addition of both nitrite and nitrate stimulated the anaerobic methane oxidation, while the stimulation by nitrite is more significant than nitrate. Our results provide the first evidence that the M. oxyfera-like bacteria play a more important role than the M. nitroreducens-like archaea in methane cycling in wetland systems.
亚硝酸盐和硝酸盐依赖型厌氧甲烷氧化分别由与“产甲烷菌属 Methylomirabilis oxyfera”（M. oxyfera）密切相关的 NC10 细菌和与“产甲烷菌属 Methanoperedens nitroreducens”（M. nitroreducens）密切相关的 ANME-2d 古菌介导。在这里，我们研究了中国东部淡水沼泽沉积物中 M. oxyfera 样细菌和 M. nitroreducens 样古菌的发生和活性。通过使用基于 Illumina 的总细菌和古菌 16S rRNA 基因测序，分别证实了多种 M. oxyfera 样细菌（与 M. oxyfera 的同一性>87%）和 M. nitroreducens 样古菌（与 M. nitroreducens 的同一性>96%）的存在。回收的 M. oxyfera 样细菌序列占总细菌 16S rRNA 池的 1.6-4.3%，而 M. nitroreducens 样古菌序列占总古菌 16S rRNA 池的 0.2-1.8%。基于 3%的序列差异，M. oxyfera 样细菌和 M. nitroreducens 样古菌的 16S rRNA 基因的 OTU 数分别为 78 和 72。定量 PCR 显示，M. oxyfera 样细菌的 16S rRNA 基因丰度（6.1×10-3.2×10 拷贝 g 沉积物）比 M. nitroreducens 样古菌高 2-4 个数量级（1.4×10-3.2×10 拷贝 g 沉积物）。稳定同位素实验表明，亚硝酸盐和硝酸盐的添加均刺激了厌氧甲烷氧化，而亚硝酸盐的刺激作用比硝酸盐更为显著。我们的研究结果首次提供了证据，表明 M. oxyfera 样细菌在湿地系统的甲烷循环中比 M. nitroreducens 样古菌发挥更为重要的作用。
