Co-metabolic degradation of tribenuron methyl,a sulfonylurea herbicide,by Pseudomonas sp. strain NyZ42

A co-metabolic degradation of tribenuron methyl bacterial strain NyZ42 was isolated from polluted agricultural soil and classified as genus Pseudomonas by its 16S rRNA gene sequencing. The degradation efficiency of tribenuron methyl was about 80% of the originally supplemented 200 mg l⁻¹ tribenuron methyl in liquid minimal medium within four days, when either glucose or succinate was used as a supplemental carbon source. Three intermediates formed during the degradation of tribenuron methyl mediated by strain NyZ42 were captured by LC-MS, and two alternative pathways were proposed for the microbial mediated tribenuron methyl degradation, via either cleavage of the sulfonylurea bridge or saponification of alkyl-group. Furthermore, inoculation of strain NyZ42 enhanced the degradation of tribenuron methyl in the sterilized soil samples, although the biodegradation/co-metabolism ability of NyZ42 was not obvious in the nonsterilized soil samples when compared with the indigenous microbial consortium under current laboratory conditions.