Isolation and characterization of Sporobolomyces sp. LF1 capable of degradingchlorimuron-ethyl

A yeast strain which was capable of degrading sulfonylurea herbicide chlorimuron-ethyl named as LF1 was isolated from achlorimuron-ethyl contaminated soil near the warehouse of the factory producing chlorimuron-ethyl in Shenyang City, Northeast China.The strain was identified as Sporobolomyces sp., based on its morphological and physiological characteristics and the phylogeneticanalysis of 18S rRNA gene sequence. So far, this is the only yeast strain of Sporobolomyces sp. which is able to degrade chlorimuronethyl.Incubation tests showed that when the initial concentration of chlorimuron-ethyl in culture was 5 mg/L, LF1 could degrade morethan 77% of the herbicide after incubation for 4 d at 30°C. The possible mechanism of chlorimuron-ethyl degradation by LF1 could bethe acidic hydrolysis caused by the acids from the metabolism of the yeast strain. Further study should be conducted to examine thepathways of chlorimuron-ethyl degradation by LF1 and to approach the feasibility of using LF1 to degrade the chlorimuron-ethyl insoil system.