Alkane Biodegradation Genes from Chronically Polluted Subantarctic Coastal Sediments and Their Shifts in Response to Oil Exposure
Alkane Biodegradation Genes from Chronically Polluted Subantarctic Coastal Sediments and Their Shifts in Response to Oil Exposure
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DOI：
10.1007/s00248-012-0051-9
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发表时间：
2012-10-01
影响因子：
3.6
通讯作者：
Lozada, Mariana
中科院分区：
文献类型：
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作者：
Guibert, Lilian M.;Loviso, Claudia L.;Lozada, Mariana
虽然沉积物是海洋环境中天然的烃汇，但人们对沉积物中烃类降解细菌的生态学知之甚少，特别是在寒冷地区。通过分析烷烃单加氧酶（alkB）基因文库，研究了长期污染的亚南极海岸沉积物中烷烃降解细菌种群的多样性及其对石油暴露的响应。沉积物克隆文库序列与变形菌门和放线菌门中描述的基因相关联，氨基酸与分离微生物序列的平均同源性为67%。大多数序列与来自寒冷海洋沉积物或高纬度地区土壤的未培养微生物最密切相关，突出了温度在细菌群落结构中的作用。alkB序列在不同地点和年份样品中的分布，以及实验油暴露后的选择，使我们能够在亚南极沉积物中鉴定出生态相关的alkB基因，这些基因可以作为该环境下烷烃生物降解的生物标志物。16s rRNA扩增子pyrosequencing显示，有几个属的alkB基因尚未被描述（Oleispira, Thalassospira）或以前未与石油生物降解相关（spongiibacter-原Melitea-， Maribius, Robiginitomaculum， Bizionia和Gillisia）。这些属构成了未来烃类生物降解途径基因鉴定工作的候选者。
Although sediments are the natural hydrocarbon sink in the marine environment, the ecology of hydrocarbon-degrading bacteria in sediments is poorly understood, especially in cold regions. We studied the diversity of alkane-degrading bacterial populations and their response to oil exposure in sediments of a chronically polluted Subantarctic coastal environment, by analyzing alkane monooxygenase (alkB) gene libraries. Sequences from the sediment clone libraries were affiliated with genes described in Proteobacteria and Actinobacteria, with 67 % amino acid identity in average to sequences from isolated microorganisms. The majority of the sequences were most closely related to uncultured microorganisms from cold marine sediments or soils from high latitude regions, highlighting the role of temperature in the structuring of this bacterial guild. The distribution of alkB sequences among samples of different sites and years, and selection after experimental oil exposure allowed us to identify ecologically relevant alkB genes in Subantarctic sediments, which could be used as biomarkers for alkane biodegradation in this environment. 16 S rRNA amplicon pyrosequencing indicated the abundance of several genera for which no alkB genes have yet been described (Oleispira, Thalassospira) or that have not been previously associated with oil biodegradation (Spongiibacter-formerly Melitea-, Maribius, Robiginitomaculum, Bizionia and Gillisia). These genera constitute candidates for future work involving identification of hydrocarbon biodegradation pathway genes.