Simultaneous biodegradation of bifenthrin and chlorpyrifos by Pseudomonas sp. CB2

ABSTRACT

The degradation of bifenthrin (BF) and chlorpyrifos (CP), either together or individually, by a bacterial strain (CB2) isolated from activated sludge was investigated. Strain CB2 was identified as belonging to genus Pseudomonas based on the morphological, physiological, and biochemical characteristics and a homological analysis of the 16S rDNA sequence. Strain CB2 has the potential to degrade BF and CP, either individually or in a mixture. The optimum conditions for mixture degradation were as follows: OD_600nm = 0.5; incubation temperature = 30°C; pH = 7.0; BF-CP mixture (10 mg L⁻¹ of each). Under these optimal conditions, the degradation rate constants (and half-lives) were 0.4308 d⁻¹ (1.61 d) and 0.3377 d⁻¹ (2.05 d) for individual BF and CP samples, respectively, and 0.3463 d⁻¹ (2.00 d) and 0.2931 d⁻¹ (2.36 d) for the BF-CP mixture. Major metabolites of BF and CP were 2-methyl-3-biphenylyl methanol and 3,5,6-trichloro-2-pyridinol, respectively. No metabolite bioaccumulation was observed. The ability of CB2 to efficiently degrade BF and CP, particularly in a mixture, may be useful in bioremediation efforts.

KEYWORDS:

• Biodegradation
• bifenthrin
• chlorpyrifos
• Pseudomonas sp

Acknowledgments

This work was supported by the National Natural Science Foundation of China (grant number 41401270), the Fundamental Scientific Research Funds of the Chinese Academy of Tropical Agricultural Sciences (grant number 1630042014003), and the Natural Science Foundation of Hainan Province (grant number 314095).

Additional information

Funding

Fundamental Scientific Research Funds of the Chinese Academy of Tropical Agricultural Sciences (1630042014003); Natural Science Foundation of Hainan Province (314095); National Natural Science Foundation of China (41401270).