Abstract: In this paper, a bacterium YN5 capable of degrading 1,2-DCA was screened from soil contaminated with 1,2-dichloroethane (1,2-DCA) in a chemical plant. Through morphological observation, physiological and biochemical tests, and 16S rRNA sequence analysis, the strain was preliminarily identified asAncylobactersp.. The growth and degradation characteristics of strain YN5 were investigated by single factor experiment, and the strain was applied to the remediation of contaminated soil. The experimental results showed that strain YN5 could degrade 1,2-DCA effectively under the conditions of pH 7－10, NaCl mass concentration 1－10 g/L, and temperature 20－40 ℃. Under the optimal condition (temperature 30 ℃, pH 9, NaCl mass concentration 1 g/L), YN5 could completely degrade 200 mg/L of 1,2-DCA within 16 h. Under laboratory simulation conditions, the 2-day removal rate of YN5 on 130 mg/kg 1,2-DCA contaminated soil reached 77.10%. It was found that soil moisture content and ambient temperature significantly affected the remediation effect of strain YN5. In addition, the soil enzyme activity after YN5 restoration was significantly improved, with the urease activity showing the most obvious improvement, increasing by 130.83%. Strain YN5 had the ability to efficiently degrade 1,2-DCA efficiently, showing potential application prospects in the remediation of 1,2-DCA contaminated soil.

Key words: 1,2-dichloroethane, Ancylobacter, bioremediation, soil remediation, soil enzyme activity