title: Aerobic degradation of trichloroethylene by co-metabolism using phenol and gasoline as growth substrates.
abstract: Trichloroethylene (TCE) is a common groundwater contaminant of toxic and carcinogenic concern. Aerobic co-metabolic processes are the predominant pathways for TCE complete degradation. In this study, Pseudomonas fluorescens was studied as the active microorganism to degrade TCE under aerobic condition by co-metabolic degradation using phenol and gasoline as growth substrates. Operating conditions influencing TCE degradation efficiency were optimized. TCE co-metabolic degradation rate reached the maximum of 80% under the optimized conditions of degradation time of 3 days, initial OD600 of microorganism culture of 0.14 (1.26×10⁷ cell/mL), initial phenol concentration of 100 mg/L, initial TCE concentration of 0.1 mg/L, pH of 6.0, and salinity of 0.1%. The modified transformation capacity and transformation yield were 20 μg (TCE)/mg (biomass) and 5.1 μg (TCE)/mg (phenol), respectively. Addition of nutrient broth promoted TCE degradation with phenol as growth substrate. It was revealed that catechol 1,2-dioxygenase played an important role in TCE co-metabolism. The dechlorination of TCE was complete, and less chlorinated products were not detected at the end of the experiment. TCE could also be co-metabolized in the presence of gasoline; however, the degradation rate was not high (28%). When phenol was introduced into the system of TCE and gasoline, TCE and gasoline could be removed at substantial rates (up to 59% and 69%, respectively). This study provides a promising approach for the removal of combined pollution of TCE and gasoline.
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. liyanid@hotmail.com.
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. libingnankai@163.com.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. wangcp@nankai.edu.cn.
authors.forename: Cui-Ping
authors.initials: CP
authors.lastname: Wang
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. cookcoolcc@126.com.
authors.forename: Jun-Zhao
authors.initials: JZ
authors.lastname: Fan
authors.affiliation: MOE Key Laboratory of Pollution Processes and Environmental Criteria, College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China. sunhongwen@nankai.edu.cn.
authors.forename: Hong-Wen
authors.initials: HW
authors.lastname: Sun
mesh_terms: D001673:Biodegradation, Environmental; D018533:Biomass; D005742:Gasoline / Q000382:microbiology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010636:Phenols / Q000737:chemistry / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000378:metabolism*; D014241:Trichloroethylene / Q000737:chemistry / Q000378:metabolism*
chemical_list: D005742:Gasoline; D010636:Phenols; D014241:Trichloroethylene