Department of Microbiology, Max Planck Institute for Marine Microbiology, Celsiusstrasse 1, Bremen, Germany.
ISME J. 2013 May;7(5):885-95. doi: 10.1038/ismej.2012.159. Epub 2012 Dec 20.
The short-chain, non-methane hydrocarbons propane and butane can contribute significantly to the carbon and sulfur cycles in marine environments affected by oil or natural gas seepage. In the present study, we enriched and identified novel propane and butane-degrading sulfate reducers from marine oil and gas cold seeps in the Gulf of Mexico and Hydrate Ridge. The enrichment cultures obtained were able to degrade simultaneously propane and butane, but not other gaseous alkanes. They were cold-adapted, showing highest sulfate-reduction rates between 16 and 20 °C. Analysis of 16S rRNA gene libraries, followed by whole-cell hybridizations with sequence-specific oligonucleotide probes showed that each enrichment culture was dominated by a unique phylotype affiliated with the Desulfosarcina-Desulfococcus cluster within the Deltaproteobacteria. These phylotypes formed a distinct phylogenetic cluster of propane and butane degraders, including sequences from environments associated with hydrocarbon seeps. Incubations with (13)C-labeled substrates, hybridizations with sequence-specific probes and nanoSIMS analyses showed that cells of the dominant phylotypes were the first to become enriched in (13)C, demonstrating that they were directly involved in hydrocarbon degradation. Furthermore, using the nanoSIMS data, carbon assimilation rates were calculated for the dominant cells in each enrichment culture.
短链非甲烷烃丙烷和丁烷可显著影响受石油或天然气渗漏影响的海洋环境中的碳和硫循环。在本研究中，我们从墨西哥湾和 Hydrate Ridge 的海洋油气冷渗出物中富集并鉴定了新型的丙烷和丁烷降解硫酸盐还原菌。获得的富集培养物能够同时降解丙烷和丁烷，但不能降解其他气态烷烃。它们是低温适应的，在 16 到 20°C 之间表现出最高的硫酸盐还原速率。16S rRNA 基因文库分析，随后用与序列特异性寡核苷酸探针进行的全细胞杂交表明，每个富集培养物都由一个独特的与脱硫弧菌-脱硫球菌属内的 δ 变形菌门的聚类相关的生物型主导。这些生物型形成了丙烷和丁烷降解菌的独特系统发育聚类，包括与烃类渗漏有关的环境中的序列。用（13）C 标记的底物进行孵育，用序列特异性探针进行杂交和纳米 SIMS 分析表明，优势生物型的细胞首先在（13）C 中富集，证明它们直接参与了烃类降解。此外，利用纳米 SIMS 数据，计算了每个富集培养物中优势细胞的碳同化速率。
