二氯喹啉酸降解菌MC-10的筛选、鉴定及其降解特性

Screening，identification and characterization of a quinclorac-degrading Arthrobacter sp．MC-10

摘要:

摘要:【目的】为治理稻-烟轮作田块上茬土壤中二氯喹啉酸残留问题，筛选高效降解细菌菌株。【方法】通过富集培养和选择培养，从常年施用二氯喹啉酸的水稻田中筛选可以降解二氯喹啉酸的细菌;对其进行形态学观察、生理生化特征测定和16S rDNA序列系统发育鉴定。【结果】分离的降解菌株MC-10被鉴定为节杆属菌株(Arthrobacter sp． )。菌株MC-10 在5% 接种量pH 7、28℃时，对初始浓度为20 mg /L二氯喹啉酸7 d可降解90%以上。该降解菌的最佳降解条件为pH 7、30℃，二氯喹啉酸初始浓度在1－100 mg/L间均有良好的降解效果;菌株MC-10在土壤中对二氯喹啉酸同样有良好的降解效果，温室内7 d对二氯喹啉酸污染土壤的修复率可达70%。【结论】菌株MC-10在二氯喹啉酸污染土壤和水质治理中具有潜在的应用前景。

Abstract:

Abstract:［Objective］ We screened and isolated bacterial strains from the perennial administration quinclorac paddy fields to degrade quinclorac．［Methods］ Strain MC-10，which can degrade quinclorac efficiently，was screened by enrichment and selective medium． The strain was identified by morphological，physio-biochemical characteristics and 16S rDNA gene sequence analysis．［Results］MC-10 was identified as Arthrobacter sp．Under the optimal growth conditions with inoculum concentration of 5% ，at 28 C，pH 7 for 7 d，MC-10 degraded more than 90% of quinclorac．MC-10 can effectively degrade quinclorac when quinclorac initial concentration at 1 mg/L－100 mg/L．And the strain MC-10 has a good ability to survive in the soil．More than 70% quinclorac in the soil can be degraded efficiently after 7 days of cultivation．［Conclusion］ Arthrobacter sp．MC-10 could be a promising microorganism in dealing with quinclorac pollution．