Salinity Affects the Composition of the Aerobic Methanotroph Community in Alkaline Lake Sediments from the Tibetan Plateau
Salinity Affects the Composition of the Aerobic Methanotroph Community in Alkaline Lake Sediments from the Tibetan Plateau
复制标题
盐度影响青藏高原碱性湖泊沉积物中好氧甲烷氧化菌群落的组成。
DOI：
10.1007/s00248-016-0879-5
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发表时间：
2017-01-01
影响因子：
3.6
通讯作者：
Conrad, Ralf
中科院分区：
文献类型：
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作者：
Deng, Yongcui;Liu, Yongqin;Conrad, Ralf
青藏高原湖泊分布广泛，对天然甲烷排放具有重要作用。湖泊沉积物中的好氧甲烷氧化菌减少了释放到大气中的甲烷量。然而，到目前为止，还没有研究分析甲烷氧化菌群落组成及其驱动因素，这些高海拔湖泊（> 4000米）的沉积物。为了给这方面的研究提供新的认识，对青藏高原6个高海拔碱性湖泊（包括淡水湖和咸水湖）沉积物的丰度和组成进行了研究。采用定量PCR、末端限制性片段长度多态性分析和454焦磷酸测序方法对pmoA基因进行靶向分析。pmoA基因拷贝数为10（4）~10（6）/g新鲜沉积物。西藏湖泊沉积物中以Ⅰ型甲烷氧化菌为主，淡水湖泊中以甲基杆菌属和未培养的Ib型甲烷氧化菌为主，咸水湖泊中以甲基微菌属为主。将西藏湖泊的pmoA-焦磷酸测序数据与其他地区湖泊沉积物的pmoA-测序数据相结合，检测到显著的盐度和碱度效应（P = 0.001），特别是盐度，其解释了类似于25%的甲烷氧化菌群落变异。主要影响是甲基微菌是占主导地位的（高达100%），只有在盐湖。然而，在淡水湖泊中，甲烷氧化菌的组成是相对多样化的，包括甲基杆菌，甲基孢囊菌，和未培养的Ib型集群。这项研究提供了高海拔湖泊沉积物（> 4000米）的第一个甲烷氧化菌数据，并表明盐度是好氧甲烷氧化菌群落组成的驱动因素。
Lakes are widely distributed on the Tibetan Plateau, which plays an important role in natural methane emission. Aerobic methanotrophs in lake sediments reduce the amount of methane released into the atmosphere. However, no study to date has analyzed the methanotroph community composition and their driving factors in sediments of these high-altitude lakes (> 4000 m). To provide new insights on this aspect, the abundance and composition in the sediments of six high-altitude alkaline lakes (including both freshwater and saline lakes) on the Tibetan Plateau were studied. The quantitative PCR, terminal restriction fragment length polymorphism, and 454-pyrosequencing methods were used to target the pmoA genes. The pmoA gene copies ranged 10(4)-10(6) per gram fresh sediment. Type I methanotrophs predominated in Tibetan lake sediments, with Methylobacter and uncultivated type Ib methanotrophs being dominant in freshwater lakes and Methylomicrobium in saline lakes. Combining the pmoA-pyrosequencing data from Tibetan lakes with other published pmoA-sequencing data from lake sediments of other regions, a significant salinity and alkalinity effect (P = 0.001) was detected, especially salinity, which explained similar to 25% of methanotroph community variability. The main effect was Methylomicrobium being dominant (up to 100%) in saline lakes only. In freshwater lakes, however, methanotroph composition was relatively diverse, including Methylobacter, Methylocystis, and uncultured type Ib clusters. This study provides the first methanotroph data for high-altitude lake sediments (> 4000 m) and shows that salinity is a driving factor for the community composition of aerobic methanotrophs.