Assessing BTEX Biodegradation Potential at a Refinery Using Molecular Biological Tools
Assessing BTEX Biodegradation Potential at a Refinery Using Molecular Biological Tools
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DOI：
10.1111/gwmr.12037
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发表时间：
2014-12-01
影响因子：
1.9
通讯作者：
Biernacki, Anita
中科院分区：
文献类型：
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作者：
Key, Katherine C.;Sublette, Kerry L.;Biernacki, Anita
对中西部一家炼油厂受碳氢化合物影响的地下水和包气带进行了微生物调查，利用分子生物学工具阐明了地下生物修复所涉及的微生物过程。对地下水中培养的生物圈闭进行的定量聚合酶链式反应分析表明，整个场地存在大量多样的微生物群落，表明苯、甲苯、乙苯和二甲苯(BTEX)的生物降解机制包括好氧氧化、硫酸盐还原、产甲烷和可能的Fe+3还原。为了评估包气带微生物在碳氢化合物衰减中的作用，从土壤岩心样品中提取RNA，RT-qPCR分析表明，包气带微生物的活性通常随着深度的增加而增加，这可能是由地下水中挥发的碳氢化合物和甲烷支持的。C-13(6)-苯的稳定同位素探测(SIP)在所研究的8口井中的6口井提供了苯生物降解的直接证据。从距离河流最近的两个监测井提取的溶解无机碳(DIC)中检测到的C-13水平最高。来自河流的营养物质和氧气的流入可能有助于维持这些油井中碳氢化合物降解者的强劲数量。虽然qPCR分析表明，现场普遍存在具有碳氢化合物生物降解遗传潜力的微生物，但利用RT-qPCR和SIP结果，通过确定遗传潜力活跃表达的区域和生物降解滞后的位置，改进了场地概念模型。
A microbial survey of hydrocarbon-impacted groundwater and vadose zone at a Midwestern refinery employed molecular biological tools to elucidate the microbial processes involved in bioremediation occurring in the subsurface. qPCR analysis of bio-traps incubated in groundwater indicated that a large and diverse microbial community was present throughout the site and suggested that mechanisms of benzene, toluene, ethylbenzene, and xylene (BTEX) biodegradation included aerobic oxidation, sulfate reduction, methanogenesis, and possibly Fe+3 reduction. To assess the role of vadose zone microorganisms in hydrocarbon attenuation, RNA was extracted from soil core samples, and reverse transcriptase-qPCR (RT-qPCR) analysis indicated that microbial activity in the vadose zone generally increased with depth, likely supported by hydrocarbons and methane volatilizing from the groundwater. Stable isotope probing (SIP) with C-13(6)-benzene provided direct evidence of benzene biodegradation in six of the eight wells studied. The highest levels of C-13 were detected in dissolved inorganic carbon (DIC) extracted from the two monitoring wells closest to the river. The influx of nutrients and oxygen coming from the river may help to maintain a robust population of hydrocarbon degraders in these wells. While qPCR analysis indicated that microorganisms with the genetic potential for hydrocarbon biodegradation were ubiquitous at the site, RT-qPCR and SIP results were used to refine the site conceptual model by identifying areas where that genetic potential was actively being expressed and locations where biodegradation was lagging.