Journal of Ecology and Rural Environment ›› 2016, Vol. 32 ›› Issue (6): 1018-1023.doi: 10.11934/j.issn.1673-4831.2016.06.024

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Isolation, Immobilization and Characterization of Quinclorac-Degrading Strain Pseudomonas stutzeri PFS-4

ZHANG Ke1, WU Yi-qi2, CHEN Wei1, GE Sang2, CHEN Jia1, LUO Hong-bing1   

  1. 1. College of Civil Engineering, Sichuan Agricultural University, Dujiangyan 611830, China;
    2. School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin 150090, China
  • Online:2016-11-25 Published:2016-11-30

Abstract:

Using quinclorac as carbon source, one strain, named PFS-4, was isolated from long-term contaminated soil. Strain PFS-4 was identified as Pseudomonas stutzeri based on physiological and biochemical characteristics and 16S rRNA sequence analysis. PFS-4 immobilization condition was optimized by orthogonal experiment, and then the effects of different temperature, initial pH, carbon and nitrogen sources on the degradation of quinclorac by the immobilized bacteria were examined. The performance of free bacteria and immobilized bacteria in actual wastewater were also detected. The results show that the optimal conditions for immobilization were as follows:alginate concentration 5%, calcium chloride 4%, bacteria cement ratio 1:2, crosslinking time 5 h. The immobilized bacteria could effectively degrad 92.3% of quinclorac (500 mg·L-1) after 5 d inoculation at the condition of 30℃ and pH 7.0. The results also revealed that the degradation rate decreased when treating actual wastewater. The degradation rate of free bacteria was significantly inhibited (P<0.01)when treating wastewater, on the contrary,immobilized bacteria were less affected and the removal rate remained above 64%. Therefore, wheat-straw adsorption-sodium alginate immobilized bacteria can be applied in quinclorac biodegradation treatment because of its good buffering to adverse circumstances.

Key words: quinclorac, wheat straw-SA carrier, immobilization, biodegradation

CLC Number: