高效降解有机磷农药真菌的分离鉴定及其特性研究%The Screening, Identification and Characterization of High-efficiency Organophosphorus-degrading Fungis
河南省微生物工程重点实验室,郑州450008;河南省科学院生物研究所有限责任公司,郑州450008 河南省科学院生物研究所有限责任公司,郑州,450008 河南省微生物工程重点实验室,郑州,450008
2011-10-08
有机磷农药 氧化乐果 驯化 曲霉 降解
从有机磷农药严重污染的土壤中分离筛选出有机磷农药高效广谱降解真菌,并对其进行鉴定及降解特性研究.通过有机磷农药驯化培养、形态学和生理生化特性及其18S rDNA序列分析等试验对其进行初步鉴定,研究外界因素初始pH、培养温度、氧化乐果初始浓度等对降解菌的生长量和降解能力的影响.通过驯化分离筛选等过程从污染土壤中筛选到2株可以在高浓度氧化乐果环境下生长的真菌J4和J6,它们经生理生化和18 S rDNA序列测定初步鉴定均为黑曲霉(Aspergillus niger).研究发现,J4和J6菌株在氧化乐果初始浓度1000 mg/L,pH值分别为6.5和6.0,温度分别为30℃和28℃,摇床转速160 r/min条件下,培养5天后降解菌可达到最佳生长量和降解能力,降解率可分别达77.83%和70.81%,耐受氧化乐果的最大浓度均为5000 mg/L,其生长量和降解能力具有正比例相关性变化趋势;并进一步研究发现,曲霉J4和J6还具有广谱降解有机磷农药的特性.%The aim was to isolate and screen the high-efficiency and broad-spectrum biodegradating fungis from the contaminated soil to a high concentration of omethoate,and study the degradation characterizations.In this study,high-efficiency organophosphorus-degrading fungis were selected through domestication,separation,screening process.They were preliminaryly identified by a series of fungi colony morphological,physiological characteristics and 18S rDNA sequences and other tests.The effects of external factors such as initial pH,culture temperature,initial omethoate concentration on growth and omethoate-degradation of strains were studied.Two strains J4 and J6 were screened and identified as Aspergillus niger.Under the conditions of culture time 5 days,initial omethoate concentration 1000 mg/L,initial pH 6.0 and 6.5 respectively,temperature 30℃ and 28℃,shaking speed 160 r/min,the strains could grow best and have the highest biodegradation rates of 77.83% and 70.81%.And the growth of the strains related positively to the biodegradation rate of omethoate.And it should also be noted that Aspergillus J4 and J6 still had characteristic of broad-spectrum degradation organophosphorus pesticides.
