Abstract Culture-independent metagenomic analysis was used to characterize the population changes undergone by a soil bacterial community after exposure to hydrocarbon fuel. Upon exposure, the soil community changed from a diverse community dominated by unclassified bacteria to a more homogeneous population of hydrocarbon-degrading bacteria dominated by Achromobacter, Azospirillum and Pseudomonas species. Attempts to culture bacteria only led to the isolation of Pseudomonas and Achromobacter species, demonstrating the insufficiency of culturing methods to characterize microbiomes. Achromobacter was the most abundant genera in the fuel enrichments but these isolates were unable to grow in fuel as a monoculture. However, when co-cultured with other hydrocarbon-degrading bacteria, including the Pseudomonas isolates, Achromobacter grew to high cell densities. Genome sequencing identified the isolate with the lowest capacity for growth in fuel as Achromobacter spanius S6 and revealed this bacterium contains many genes required for degradation of aromatics. Further analysis demonstrated A. spanius S6 required biosurfactants from other bacteria in the consortia to access and metabolize hydrocarbons. The ability of A. spanius to degrade aromatics was demonstrated by GC-MS. This study demonstrates the effect of fuel on microbial communities and characterizes an important cooperative relationship in the hydrocarbon-degrading consortia of significant implications for biodegradation and bioremediation.

中文翻译：

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宏基因组表征揭示土壤碳氢化合物降解细菌的复杂关联

摘要 不依赖培养的宏基因组分析用于表征暴露于碳氢化合物燃料后土壤细菌群落经历的种群变化。暴露后，土壤群落从以未分类细菌为主的多样化群落变为以无色杆菌、固氮螺菌和假单胞菌属为主的更均匀的碳氢化合物降解细菌群。尝试培养细菌只会导致分离出假单胞菌和无色杆菌，这表明培养方法不足以表征微生物组。无色杆菌是燃料浓缩物中最丰富的属，但这些分离物不能作为单一培养物在燃料中生长。然而，当与其他碳氢化合物降解细菌（包括假单胞菌分离株）共培养时，无色杆菌生长到高细胞密度。基因组测序鉴定出燃料中生长能力最低的分离株为 Achromobacter spanius S6，并揭示该细菌含有许多降解芳香烃所需的基因。进一步的分析表明，A. spanius S6 需要来自财团中其他细菌的生物表面活性剂来获取和代谢碳氢化合物。GC-MS 证明了A.spanius 降解芳烃的能力。这项研究证明了燃料对微生物群落的影响，并表征了碳氢化合物降解联盟中对生物降解和生物修复具有重要意义的重要合作关系。基因组测序鉴定出燃料中生长能力最低的分离株为 Achromobacter spanius S6，并揭示该细菌含有许多降解芳香烃所需的基因。进一步的分析表明，A. spanius S6 需要来自财团中其他细菌的生物表面活性剂来获取和代谢碳氢化合物。GC-MS 证明了A.spanius 降解芳烃的能力。这项研究证明了燃料对微生物群落的影响，并表征了碳氢化合物降解联盟中对生物降解和生物修复具有重要意义的重要合作关系。基因组测序鉴定出燃料中生长能力最低的分离株为 Achromobacter spanius S6，并揭示该细菌含有许多降解芳香烃所需的基因。进一步的分析表明，A. spanius S6 需要来自财团中其他细菌的生物表面活性剂来获取和代谢碳氢化合物。GC-MS 证明了A.spanius 降解芳烃的能力。这项研究证明了燃料对微生物群落的影响，并表征了碳氢化合物降解联盟中对生物降解和生物修复具有重要意义的重要合作关系。GC-MS 证明了spanius 降解芳烃。这项研究证明了燃料对微生物群落的影响，并表征了碳氢化合物降解联盟中对生物降解和生物修复具有重要意义的重要合作关系。GC-MS 证明了spanius 降解芳烃。这项研究证明了燃料对微生物群落的影响，并表征了碳氢化合物降解联盟中对生物降解和生物修复具有重要意义的重要合作关系。