Liang Yi, Cook Laura J, Mattes Timothy E
Department of Civil and Environmental Engineering, University of Iowa, 4105 Seamans Center, Iowa City, IA, 52242, USA.
CH2M 5701 Cleveland Street Suite 200, Virginia Beach, VA, 23462, USA.
Environ Sci Pollut Res Int. 2017 May;24(15):13760-13774. doi: 10.1007/s11356-017-8948-y. Epub 2017 Apr 11.
Assessment and monitoring of microbial community dynamics is useful when tracking the progress of vinyl chloride (VC) bioremediation strategies, particularly in dilute plumes where apparent VC attenuation rates are low. In a long-term field study, the abundance and the activity of microbial VC degraders were tracked in three monitoring wells (MW05, MW25, and MW19) along a dilute VC plume at Naval Air Station (NAS) Oceana. High-throughput sequencing of partial 16S ribosomal RNA (rRNA) genes and transcripts revealed diverse groundwater microbial communities and showed that methanotrophs and anaerobic respirers (e.g., methanogens, sulfate reducers, and iron reducers) were among the most active and abundant guilds. Quantitative PCR analysis showed that among bacterial guilds with a potential to contribute to VC biodegradation, methanotrophs were the most abundant and active microbial group. Ethene-oxidizing bacterial populations were less abundant and relatively inactive compared to methanotrophs. In MW19, expression of functional genes associated with both aerobic VC oxidation and anaerobic VC reduction was observed. Overall, our results reveal that the groundwater community contains various active bacterial guilds previously associated with metabolic and cometabolic VC degradation processes either under aerobic and anaerobic conditions that might have contributed to the slowly decreasing VC concentrations at the NAS Oceana site over the 6-year study period.
在追踪氯乙烯（VC）生物修复策略的进展时，对微生物群落动态进行评估和监测是很有用的，特别是在表观VC衰减率较低的稀释羽流中。在一项长期的现场研究中，沿着海军航空站（NAS）奥西阿纳的一条稀释VC羽流，在三个监测井（MW05、MW25和MW19）中追踪了微生物VC降解菌的丰度和活性。对部分16S核糖体RNA（rRNA）基因和转录本进行高通量测序，揭示了多样的地下水微生物群落，并表明甲烷氧化菌和厌氧呼吸菌（如产甲烷菌、硫酸盐还原菌和铁还原菌）是最活跃和丰度最高的类群。定量PCR分析表明，在有可能促进VC生物降解的细菌类群中，甲烷氧化菌是最丰富和活跃的微生物群体。与甲烷氧化菌相比，乙烯氧化细菌群体丰度较低且相对不活跃。在MW19中，观察到了与好氧VC氧化和厌氧VC还原相关的功能基因的表达。总体而言，我们的结果表明，在为期6年的研究期间，地下水群落包含各种先前与有氧和厌氧条件下的代谢性和共代谢性VC降解过程相关的活跃细菌类群，这些细菌类群可能促成了NAS奥西阿纳场地VC浓度的缓慢下降。
