School of Civil and Environmental Engineering, Yonsei University, Seoul, 120-749, South Korea.
Microb Ecol. 2012 Aug;64(2):485-98. doi: 10.1007/s00248-012-0036-8. Epub 2012 Mar 24.
The effects of elevated CO(2) on soil bacterial community with upland vegetation have been widely studied, but limited information is available regarding responses of denitrifier and methanogen communities to elevated CO(2) in wetland ecosystems. Using restriction fragment length polymorphism (RFLP), terminal RFLP analysis, and real-time quantitative PCR, we compared communities of denitrifiers and methanogens in a laboratory-scale wetland system planted with one of three macrophytes, Typha latifolia, Scirpus lacustris, or Juncus effusus, after 110 days of incubation. Our study showed that elevated CO(2) could affect community structures of both denitrifiers and methanogens, each of which had a unique response pattern. In particular, elevated CO(2) shifted nirS-containing community with a unique structure irrespective of vegetation type. mcrA-containing community appeared to shift to community with unique types of hydrogenotrophs under elevated CO(2) conditions. The change of dissolved organic carbon driven by elevated CO(2) appeared to be related with the shift of both denitrifiers and methanogens. Overall, this study indicates that elevated CO(2) could change the community structure of denitrifiers and methanogens temporarily. These results also suggest a presence of stable dominant populations that were not substantially affected by changes in CO(2) concentration.
大气 CO2 浓度升高对旱地植被土壤细菌群落的影响已得到广泛研究，但湿地生态系统中硝化菌和产甲烷菌对大气 CO2 浓度升高响应的信息有限。本研究采用限制性片段长度多态性（RFLP）、末端 RFLP 分析和实时定量 PCR 技术，比较了种植三种大型植物（香蒲、藨草或芦苇）的实验室规模湿地系统中硝化菌和产甲烷菌在 110 天培养后的群落。结果表明，大气 CO2 浓度升高会影响硝化菌和产甲烷菌的群落结构，它们各自具有独特的响应模式。特别是，大气 CO2 浓度升高会使nirS 基因丰度所代表的硝化菌群落结构发生改变，而与植被类型无关。在大气 CO2 浓度升高条件下，mcrA 基因丰度所代表的产甲烷菌群落似乎向以氢营养型产甲烷菌为主的群落结构转变。由大气 CO2 浓度升高引起的溶解性有机碳的变化似乎与硝化菌和产甲烷菌的变化有关。总之，本研究表明大气 CO2 浓度升高会暂时改变硝化菌和产甲烷菌的群落结构。这些结果还表明存在稳定的优势种群，它们不会受到 CO2 浓度变化的显著影响。
