%0 Journal Article %T 不同水分条件下格陵兰岛冻土活性甲烷氧化菌群落分异规律 %T The Emergence of Novel Methane Oxidizers in Greenland Permafrost Soil Under Periodically Water Saturated Conditions %A 刘 蓓 %A Bo Elberling %A 贾仲君 %A LIU,Bei %A BO,Elberling %A JIA,Zhongjun %J 土壤 %J Soils %@ 0253-9829 %V 52 %N 1 %D 2020 %P 90-96 %K 好氧甲烷氧化菌;活动层;稳定性同位素示踪DNA;冻土;土壤含水量 %K Aerobic methanotrophs; Active layer; DNA-Stable isotope probing; Permafrost; Water moisture %X 揭全球气候变化导致丹麦格陵兰岛形成了旱地和间歇淹水的土壤景观,采用稳定性同位素核酸探针技术和高通量测序16S rRNA及pmoA基因的分析方法,开展了格陵兰岛旱地和间歇淹水土壤微宇宙培养试验,探究不同水分条件下冻土的甲烷氧化潜力及活性好氧甲烷氧化菌群落演替规律。结果表明:与旱地土壤相比,淹水土壤氧化高浓度甲烷的速率呈现降低趋势,分别为12.38和 12.17 μg/(g·d),但后者对甲烷碳同化利用效率显著高于前者,土壤13C-有机碳原子百分比从自然丰度1.08%,分别增加至1.64% 和1.99%。超高速密度梯度离心分析13C-DNA发现甲烷氧化菌群落发生演替,旱地土壤中Crenothrix甲烷氧化菌16S rRNA基因丰度仅为0.04%,而在间歇淹水土壤中为23.78%,增幅高达557倍;类型II甲烷氧化菌Methylosinus则从33.76% 增至44.38%。然而,类型I甲烷氧化菌Methylocaldum的丰度明显降低,从旱地土壤10.15% 显著降低为间歇淹水0.14%;进一步通过pmoA基因高通量测序分析,也得到了类似的结果,特别是类型I甲烷氧化菌RPCs从旱地土壤15.61% 显著降低至间歇淹水土壤的0.13%。这些结果表明:尽管格陵兰冻土中经典的类型II甲烷氧化菌主导了旱地土壤和间歇性淹水土壤好氧甲烷氧化过程,但水分可能是甲烷氧化菌群落演替的重要环境驱动力,水分增加导致活性的类型I种群丰度降低,同时显著刺激了新型甲烷氧化菌Crenothrix的大量生长并可能在间歇淹水土壤中发挥了重要作用。 %X This study investigated the impact of soil moisture on methane oxidation potential and the species of active methanotrophs in two contrasting soil types: permanent aerobic upland and periodically water saturated land in Zackenberg, Greenland. Each soil sample was incubated in a 120 ml bottles with 5% 13C-methane or with air in case of the control treatment. Stable isotope probing was used to label the active methanotrophs, while high throughput sequencing of the 16S rRNA and pmoA genes was performed to analyze how the active methanotrophs change in abundance and composition in response to the different soil moisture conditions. Both soil samples showed high activity of aerobic methane oxidation, but the periodically water saturated land developed the higher potential of carbon assimilation. The difference between the species with subprime status in the two types of soil samples could explain the variance of soil methane oxidation and carbon assimilation. The results indicated that the periodical water saturation promote methane oxidation by altering the composition of the subprime active methanotrophs (Methylocaldum and Crenothrix) rather than the dominant ones (Methylocystis/Methylosinus) in permafrost soil. %R 10.13758/j.cnki.tr.2020.01.013 %U http://soils.issas.ac.cn/tr/home %1 JIS Version 3.0.0