Rare Branched Fatty Acids Characterize the Lipid Composition of the Intra-Aerobic Methane Oxidizer "Candidatus Methylomirabilis oxyfera"
Rare Branched Fatty Acids Characterize the Lipid Composition of the Intra-Aerobic Methane Oxidizer "Candidatus Methylomirabilis oxyfera"
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DOI：
10.1128/aem.02099-12
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发表时间：
2012-12-01
影响因子：
4.4
通讯作者：
Damste, Jaap S. Sinninghe
中科院分区：
文献类型：
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作者：
Kool, Dorien M.;Zhu, Baoli;Damste, Jaap S. Sinninghe
最近发现的细菌“oxyfera Candidatus methylirabilis oxyfera”将重要温室气体甲烷的氧化与亚硝酸盐的还原结合在一起。“Ca. methylirabilis oxyfera”的生态意义仍未得到充分探索，因为我们识别这种细菌存在的能力迄今为止仅限于基于dna的技术。在这里，我们研究了“Ca. Methylomirabilis oxyfera”的脂质组成，以确定新的、基因无关的生物标志物，用于该细菌的环境检测。研究了多种“氧化亚甲基化钙”富集培养。在所有培养中，脂肪酸（FA） 10-甲基十六烷酸（10MeC(16:0)）在脂质谱中占46%的主导地位。此外，还发现了一种其他地方未报道的独特FA：在Delta 7位置具有双键的单不饱和10-甲基十六烯酸（10MeC(16:1 Delta 7)），占总FA谱的10%。我们认为典型的支链脂肪酸10MeC（16:0）和10MeC（16:1 Delta 7）是“Ca. Methylomirabilis oxyfera”脂质谱的关键和特征组分。在泥炭地成功检测到这些脂肪酸，其中一种富集培养物起源于泥炭地，这支持了这些独特的脂质作为环境中亚硝酸盐依赖性甲烷氧化过程的生物标志物的潜力。
The recently described bacterium "Candidatus Methylomirabilis oxyfera" couples the oxidation of the important greenhouse gas methane to the reduction of nitrite. The ecological significance of "Ca. Methylomirabilis oxyfera" is still underexplored, as our ability to identify the presence of this bacterium is thus far limited to DNA-based techniques. Here, we investigated the lipid composition of "Ca. Methylomirabilis oxyfera" to identify new, gene-independent biomarkers for the environmental detection of this bacterium. Multiple "Ca. Methylomirabilis oxyfera" enrichment cultures were investigated. In all cultures, the lipid profile was dominated up to 46% by the fatty acid (FA) 10-methylhexadecanoic acid (10MeC(16:0)). Furthermore, a unique FA was identified that has not been reported elsewhere: the monounsaturated 10-methylhexadecenoic acid with a double bond at the Delta 7 position (10MeC(16:1 Delta 7)), which comprised up to 10% of the total FA profile. We propose that the typical branched fatty acids 10MeC(16:0) and 10MeC(16:1 Delta 7) are key and characteristic components of the lipid profile of "Ca. Methylomirabilis oxyfera." The successful detection of these fatty acids in a peatland from which one of the enrichment cultures originated supports the potential of these unique lipids as biomarkers for the process of nitrite-dependent methane oxidation in the environment.