Isolation, identification, and optimization of degradation conditions of the acetamiprid-degrading strain D35 from drilosphere

Abstract:

[Background] The residues of acetamiprid and other neonicotinoid insecticides have adverse effects on non-target beneficial organisms, and bacteria can promote the degradation of them. [Objective] To isolate acetamiprid-degrading strain from drilosphere and optimize the degradation conditions to improve the degradation rate. [Methods] The acetamiprid-degrading strain was isolated from drilosphere and identified based on 16S rRNA gene sequencing and physiological and biochemical characteristics. The degradation conditions were optimized by single factor test, Plackett-Burman design, steepest ascent path design, and Box-Behnken design. [Results] Strain D35 could degrade more than 55.46% of 50 mg/L acetamiprid within 72 h, and was identified as Pseudomonas sp. The optimized conditions were tryptone 10.19 g/L, 30 ℃, inoculum size 5.24%, pH 7.0, and acetamiprid at initial concentration of 50 mg/L. The degradation rate of D35 under the optimized conditions hit 80.21% within 72 h, 24.75% higher than that before the optimization. [Conclusion] We screened the neonicotinoids-degrading bacteria and strain D35 could efficiently degrade acetamiprid, which provided microbial resource for rapidly eliminating acetamiprid in the environment.