Bredesen Center for Interdisciplinary Research and Graduate Education , University of Tennessee , Knoxville , Tennessee 37996 , United States.
Biosciences Division , Oak Ridge National Laboratory , Oak Ridge , Tennessee 37830 , United States.
Environ Sci Technol. 2018 May 15;52(10):5989-5999. doi: 10.1021/acs.est.8b00239. Epub 2018 Apr 30.
The environmental impacts of hydraulic fracturing, particularly those of surface spills in aquatic ecosystems, are not fully understood. The goals of this study were to (1) understand the effect of previous exposure to hydraulic fracturing fluids on aquatic microbial community structure and (2) examine the impacts exposure has on biodegradation potential of the biocide glutaraldehyde. Microcosms were constructed from hydraulic fracturing-impacted and nonhydraulic fracturing-impacted streamwater within the Marcellus shale region in Pennsylvania. Microcosms were amended with glutaraldehyde and incubated aerobically for 56 days. Microbial community adaptation to glutaraldehyde was monitored using 16S rRNA gene amplicon sequencing and quantification by qPCR. Abiotic and biotic glutaraldehyde degradation was measured using ultra-performance liquid chromatography--high resolution mass spectrometry and total organic carbon. It was found that nonhydraulic fracturing-impacted microcosms biodegraded glutaraldehyde faster than the hydraulic fracturing-impacted microcosms, showing a decrease in degradation potential after exposure to hydraulic fracturing activity. Hydraulic fracturing-impacted microcosms showed higher richness after glutaraldehyde exposure compared to unimpacted streams, indicating an increased tolerance to glutaraldehyde in hydraulic fracturing impacted streams. Beta diversity and differential abundance analysis of sequence count data showed different bacterial enrichment for hydraulic fracturing-impacted and nonhydraulic fracturing-impacted microcosms after glutaraldehyde addition. These findings demonstrated a lasting effect on microbial community structure and glutaraldehyde degradation potential in streams impacted by hydraulic fracturing operations.
水力压裂的环境影响，特别是在水生生态系统中地表溢出的影响，尚未完全了解。本研究的目的是：（1）了解先前接触水力压裂液对水生微生物群落结构的影响；（2）研究接触对杀菌剂戊二醛生物降解潜力的影响。微宇宙由宾夕法尼亚州马塞勒斯页岩地区受水力压裂影响和不受水力压裂影响的溪流水构建而成。向微宇宙中添加戊二醛，并在有氧条件下孵育 56 天。使用 16S rRNA 基因扩增子测序和 qPCR 定量监测微生物群落对戊二醛的适应。使用超高效液相色谱-高分辨率质谱和总有机碳测量非生物和生物戊二醛降解。结果发现，未受水力压裂影响的微宇宙比受水力压裂影响的微宇宙更快地生物降解戊二醛，表明在接触水力压裂活动后降解潜力下降。与未受影响的溪流相比，暴露于戊二醛后受水力压裂影响的微宇宙显示出更高的丰富度，表明在受水力压裂影响的溪流中对戊二醛的耐受性增加。序列计数数据的β多样性和差异丰度分析表明，在添加戊二醛后，受水力压裂影响和不受水力压裂影响的微宇宙中出现了不同的细菌富集。这些发现表明水力压裂作业对受影响溪流中的微生物群落结构和戊二醛降解潜力具有持久影响。
