Isolation,identification and degradation characteristics of a Bifenthrin-degrading strain Delftia tsuruhatensis | 联苯菊酯降解菌的筛选、鉴定及其降解特性

Chinese. 筛选高效降解联苯菊酯菌株，为环境中联苯菊酯的生物修复提供菌种资源。采用室内培养法，从湖南某农药厂下水道污泥中，以联苯菊酯作为唯一碳源进行摇瓶培养筛选，以降解率作为评价指标确定高效菌株，根据生理生化特性和16S rDNA对菌株进行鉴定，并对降解的最佳温度、pH、接种量和联苯菊酯质量浓度进行了筛选。获得1株革兰氏阴性好氧杆状菌，经鉴定为戴尔福特菌（Delftia tsuruhatensis），命名为HLB-1。在pH 7.0、30 ℃、接种量100 mL/L、120 r/min的条件下培养5 d，菌株HLB-1对200 mg/L联苯菊酯的降解率可达74.5%。获得的高效降解联苯菊酯菌株，其最佳降解条件为pH 7.0，30 ℃，接种量100 mL/L，联苯菊酯质量浓度为250 mg/L。获得了1株联苯菊酯降解菌HLB-1，其具有一定的生产应用潜力，可作为环境中联苯菊酯农药生物修复的候选菌株。

English. The study was conducted to isolate effective bacteria capable of degrading Bifenthrin, a widely-used insecticide, and provide potential biological preparations for the bioremediation of Bifenthrin residues in the environment, mainly in soil. By incubation experiment, the strain isolated from the tame sludge was screened in the mineral media supplied with Bifenthrin as the sole carbon source. The most effective degrading strain was determined according to their degrading rates, and then was preliminarily identified based on the morphology observation, physiological characteristics and 16S rDNA sequence analysis. Subsequently, a research was done to investigate its degradation characteristics. A strain which had the highest capability of degrading Bifenthrin was identified to be Delftia tsuruhatensis, a gram-negative aerobe bacilli. After 5 d’s incubation, the degradation rate of Bifenthrin of 200 mg/L by the HLB-1 was 74.5%. HLB-1 could efficiently degrade Bifenthrin. Under the vibrational speed 120 r/min, its optimal condition was pH 7.0, 30 ℃, inoculated amount at 100 mL/L, Bifenthrin concentration 250 mg/L. The bifenthrin degrading strain HLB-1 has great application potential in the bioremediation of enviroment polluted by bifenthrin pesticide.