Cátedra de Microbiología, Facultad de Química, Universidad de la República-Uruguay, Montevideo, Uruguay.
J Appl Microbiol. 2009 Jan;106(1):306-16. doi: 10.1111/j.1365-2672.2008.04004.x. Epub 2008 Nov 28.
To combine molecular and cultivation techniques to characterize the methanotrophic community in the soil-water interface (SWI) and rhizospheric soil from flooded rice fields in Uruguay, a temperate region in South America.
A novel type I, related to the genus Methylococcus, and three type II methanotrophs were isolated from the highest positive dilution steps from the most probable number (MPN) counts. Potential methane oxidation activities measured in slurried samples were higher in the rhizospheric soil compared to the SWI and were stimulated by N-fertilization. PmoA (particulate methane monooxygenase) clone libraries were constructed for both rice microsites. SWI clones clustered in six groups related to cultivated and uncultivated members from different ecosystems of the genera Methylobacter, Methylomonas, Methylococcus and a novel type I sublineage while cultivation and T-RFLP (terminal restriction fragment length polymorphism) analysis confirmed the presence of type II methanotrophs.
Cultivation techniques, cloning analysis and T-RFLP fingerprinting of the pmoA gene revealed a diverse methanotrophic community in the rice rhizospheric soil and SWI.
This study reports, for the first time, the analysis of the methanotrophic diversity in rice SWI and this diversity may be exploited in reducing methane emissions.
结合分子和培养技术，对来自南美洲温带乌拉圭水淹稻田土壤-水界面（SWI）和根际土壤中的甲烷氧化菌群落进行特征描述。
从最可能数（MPN）计数的最高正稀释步骤中分离出一种新型的 I 型甲烷氧化菌，与甲基球菌属有关，以及三种 II 型甲烷氧化菌。在泥浆样品中测量的潜在甲烷氧化活性在根际土壤中高于 SWI，并且受到 N 施肥的刺激。为两个水稻微生境构建了 PmoA（颗粒态甲烷单加氧酶）克隆文库。SWI 克隆聚类为六个组，与来自不同生态系统的已培养和未培养的甲基杆菌属、甲基单胞菌属、甲基球菌属和新型 I 亚系成员有关，而培养和 T-RFLP（末端限制性片段长度多态性）分析证实了 II 型甲烷氧化菌的存在。
培养技术、克隆分析和 pmoA 基因的 T-RFLP 指纹图谱揭示了水稻根际土壤和 SWI 中存在多样的甲烷氧化菌群落。
本研究首次报道了水稻 SWI 中甲烷氧化菌多样性的分析，这种多样性可用于减少甲烷排放。
