一株广谱农药降解放线菌对敌百虫的降解特性研究

Study of the Broad-Spectrum Pesticide Degrading Actinomyces on the Trichlorfon Degradation Characteristics

本研究从农药污染土样中筛选出1株具有敌百虫降解特性的菌株Lin F-1,通过显微结构观察,生理生化测试,16S rDNA序列测定和同源性分析,初步鉴定为Streptomyces levis,属于链霉菌属。对该菌的农药降解特性研究表明,Lin F-1对有机磷、有机氯以及菊酯类等农药具有较好的广谱降解能力。在敌百虫浓度为100 mg/L,温度为28℃条件下培养1周,Lin F-1对其降解动力曲线满足降解一级动力学方程ln(Ct/Co)=-1.732 9t+1.893,其最高降解率达到63.3%,敌百虫浓度半数降解时间(DT_(50))为4.41 d。在基础培养基中,Lin F-1的敌百虫最适降解浓度为100 mg/L,同时在加入5种外源碳源的条件下,Lin F-1的生物量和敌百虫降解率均有显著性提高,最高分别达到了106.5 mg/mL和97.7%。

One strain Lin F-1,with highly trichlorfon biodegradation ability,was isolated from the pesticide polluted soil samples,and was firstly identified as Streptomyces levis by the analysis of micro-structure,physiology and biochemistry tests,the 16 S rDNA sequences and homology analysis.The broad-spectrum pesticide degradation test also proved the preferable degradation abilities of Lin F-1 in organophosphorus,organochlorine and pyrethroid pesticides.Lin F-1 was inoculated in the medium containing 100 mg/L trichlorfon at 28℃ for one week,and the degradation of power curve was measured by the first-order kinetic model as followed：ln（Ct/Co）=-1.732 9t＋1.893.The highest degradation rate,which was 63.3%,was measured after one week culturing,and the time that half of the pesticide concentration was degraded as 4.41 days.The optimum trichlorfon concentration in the mineral medium was determined as 100 mg/L.The dry weight and trichlorfon degradation rate were significantly improved with adding five kinds of different exogenous carbon sources,which reached the highest of 106.5 mg/mL and 97.7%,respectively.