为有效治理呋喃丹的污染,从受呋喃丹长期污染的土壤中分离筛选到一株高效降解呋喃丹的菌株CFDS-1,经形态、生理生化、16S rDNA(GenBank accession No.AY702969)同源性及系统发育地位等分析,将其初步鉴定为Sphingomonas sp.当接种量为5%时,CFDS-1能在48 h内降解100 mg L-1的呋喃丹,对于高达300 mg L-1的呋喃丹依然有降解效果;CFDS-1对呋喃丹的降解率与起始接种量呈正相关;降解呋喃丹的最适pH是8.0~9.0;在20~42℃范围内,温度对CFDS-1降解呋喃丹没有显著影响;该菌在250 mL三角瓶中装液量为100 mL时,对呋喃丹的降解效果最好.土壤实验表明,该菌株同样能有效地降解土壤中的呋喃丹残留.
Carbofuran(2,3-dihydro-2,2-dimethyl-7-benzofuranoyl N-methylcarbamate) was first introduced into China in 1979 as a pesticide and is extensively used as a soil-incorporated N-methylcarbamate insecticide to control a variety of insect pests that infest many kinds of crops,such as corn and potato.Carbofuran is of a concern due to its relatively high mammalian toxicity and relatively high mobility in soil.Some N-methylcarbamate compounds and their metabolites can be sufficiently mobile in certain soil,thus considered as potential pollutants of ground and surface waters.One carbofuran-degrading strain named CFDS-1 was isolated from soil polluted by carbofuran for a long time.According to its physiological biochemical characters,and the homology analysis of its 16S rDNA sequence(GenBank accession No.AY702969),CFDS-1 was primarily identif ied as Sphingomonas sp.CFDS-1 was able to completely degrade carbofuran in medium within 48 hours at the initial concentration of 100 mg L-1.CFDS-1 could well degrade carbofuran at concentrations from 20 mg L-1 to 300 mg L-1.The degradation speed was related positively to initial inoculation amount.The optimal pH and aeration for the degradation were 8.0~9.0 and 100 ~250 mL,respectively.The temperature(between 25 ℃ and 42 ℃) had no notable effect on the degradation of carbofuran by CFDS-1.CFDS-1 could well degrade carbofuran not only in medium,but also in soil.