Methylphosphonate metabolism by Pseudomonas sp. populations contributes to the methane oversaturation paradox in an oxic freshwater lake: Methylphosphonate and aquatic CH 4 oversaturation
Methylphosphonate metabolism by Pseudomonas sp. populations contributes to the methane oversaturation paradox in an oxic freshwater lake: Methylphosphonate and aquatic CH 4 oversaturation
复制标题
假单胞菌的甲基膦酸代谢。
DOI：
10.1111/1462-2920.13747
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发表时间：
2017
影响因子：
5.1
通讯作者：
McDermott, Timothy R.
中科院分区：
文献类型：
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作者：
Wang, Qian;Dore, John E.;McDermott, Timothy R.
在富氧的海洋和湖泊沃茨中观察到了“甲烷过饱和悖论”，并认为这对甲烷（一种强有力的温室气体）的生物圈循环有重大贡献。我们的研究集中在淡水湖泊中有趣的定义明确的远洋甲烷富集区（PMEZ）。用13 C标记的潜在产甲烷底物掺入黄石湖PMEZ样品，发现只有13 C甲基膦酸酯（MPn）导致13 CH 4产生。在16 S rRNA基因Illumina文库中，操作分类单位在PMEZ群落中的丰度令人惊讶地占10.11%。也从用PMEZ水富集的MPn中获得分离物;它们在MPn代谢中最具攻击性，并且它们的16 S rRNA基因序列与Illumina PMEZ假单胞菌读数的35%匹配。此外，编码C-P裂解酶的两个关键基因（phnJL，MPn脱烷基化的一种重要酶）仅可从PMEZ DNA中分离，并且所有PCR产生的phnJL克隆与假单胞菌的那些相匹配。分离株值得注意的是，产甲烷菌16 S rRNA签名在所有Illumina文库中均不存在，并且通过PCR未检测到mcrA。总的来说，这些意见是一致的结论，MPn代谢有助于显着的CH 4过饱和在黄石湖和其他可能的好氧淡水湖环境，并认为假单胞菌。人口是关键的参与者。
The ‘CH4oversaturation paradox’ has been observed in oxygen‐rich marine and lake waters, and viewed to significantly contribute to biosphere cycling of methane, a potent greenhouse gas. Our study focused on the intriguing well‐defined pelagic methane enriched zone (PMEZ) in freshwater lakes. Spiking Yellowstone Lake PMEZ samples with13C‐labeled potential methanogenesis substrates found only13C‐methylphosphonate (MPn) resulted in13CH4generation. In 16S rRNA gene Illumina libraries, fourPseudomonassp. operational taxonomic units surprisingly accounted for ∼11% abundance in the PMEZ community.Pseudomonassp. isolates were also obtained from MPn enrichments with PMEZ water; they were most aggressive in MPn metabolism and their 16S rRNA gene sequences matched 35% of the Illumina PMEZPseudomonasreads. Further, two key genes encoding C‐P lyase (phnJL, an important enzyme for dealkylation of MPn), were only amplifiable from PMEZ DNA and all PCR generatedphnJLclones matched those of thePseudomonassp. isolates. Notably, methanogen 16S rRNA signatures were absent in all Illumina libraries andmcrAwas not detected via PCR. Collectively, these observations are consistent with the conclusion that MPn metabolism contributes significantly to CH4oversaturation in Yellowstone Lake and likely other oxic freshwater lake environments, and thatPseudomonassp. populations are critical participants.