title: Shifts in microbial community structure during in situ surfactant-enhanced bioremediation of polycyclic aromatic hydrocarbon-contaminated soil.
abstract: This study aims to reveal the microbial mechanism of in situ surfactant-enhanced bioremediation (SEBR). Various concentrations of rhamnolipids, Tween 80, and sodium dodecyl benzenesulfonate (SDBS) were separately sprayed onto soils contaminated with polycyclic aromatic hydrocarbons (PAHs) for years. Within 90 days, the highest level of degradation (95 %) was observed in the soil treated with rhamnolipids (10 mg/kg), followed by 92 % degradation with Tween 80 (50 mg/kg) and 90 % degradation with SDBS (50 mg/kg). The results of the microbial phospholipid fatty acids (PLFAs) suggest that bacteria dominated the enhanced PAH biodegradation (94 % of the maximum contribution). The shift of bacterial community structure during the surfactant treatment was analyzed by using the 16S rRNA gene high-throughput sequencing. In the presence of surfactants, the number of the operational taxonomic units (OTUs) associated with Bacillus, Pseudomonas, and Sphingomonas increased from 2-3 to 15-30 % at the end of the experiment (two to three times of control). Gene prediction with phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) shows that the PAH-degrading genes, such as 1-hydroxy-2-naphthoate dioxygenase and PAH dioxygenase large subunit, significantly increased after the surfactant applications (p < 0.05). The findings of this study provide insights into the surfactant-induced shifts of microbial community, as well as critical factors for efficient bioremediation.
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China.|Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou, 310058, China.
authors.forename: Lingwen
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China.|Department of Environmental Science and Engineering, Xiangtan University, Xiangtan, 411105, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China.|Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou, 310058, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhan
authors.affiliation: Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, 310058, China. zlz@zju.edu.cn.|Zhejiang Provincial Key Laboratory of Organic Pollution Process Control, Hangzhou, 310058, China. zlz@zju.edu.cn.
authors.forename: Lizhong
authors.initials: L
authors.lastname: Zhu
mesh_terms: D001419:Bacteria / Q000235:genetics / Q000378:metabolism*; D001673:Biodegradation, Environmental; D049308:Dioxygenases / Q000378:metabolism; D010802:Phylogeny; D011084:Polycyclic Aromatic Hydrocarbons / Q000378:metabolism*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012987:Soil; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D013501:Surface-Active Agents / Q000737:chemistry
chemical_list: D011084:Polycyclic Aromatic Hydrocarbons; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants; D013501:Surface-Active Agents; C111742:1-hydroxy-2-naphthoate dioxygenase; D049308:Dioxygenases
keywords: Autochthonous biostimulation; Gene prediction; High-throughput sequencing; PAH-contaminated soil; Phospholipid fatty acid; Surfactant-enhanced bioremediation (SEBR)