Biodegradation of nicosulfuron by the bacteriumSerratia marcescensN80

Abstract

By enrichment culturing of the sludge collected from the industrial wastewater treatment pond, we isolated a highly efficient nicosulfuron degrading bacterium Serratia marcescens N80. In liquid medium, Serratia marcescens N80 grows using nicosulfuron as the sole nitrogen source, and the optimal temperature, pH values, and inoculation for degradation are 30-35°C, 6.0-7.0, and 3.0% (v/v), respectively. With the initial concentration of 10 mg L⁻¹, the degradation rate is 93.6% in 96 hours; as the initial concentrations are higher than 10 mg L⁻¹, the biodegradation rates decrease as the nicosulfuron concentrations increase; when the concentration is 400 mg L⁻¹, the degradation rate is only 53.1%. Degradation follows the pesticide degradation kinetic equation at concentrations between 5 mg L⁻¹ and 50 mg L⁻¹. Identification of the metabolites by the liquid chromatography/mass spectrometry (LC/MS) indicates that the degradation of nicosulfuron is achieved by breaking the sulfonylurea bridge. The strain N80 also degraded some other sulfonylurea herbicides, including ethametsulfuron, tribenuron-methyl, metsulfuron-methyl, chlorimuron-ethyl,and rimsulfuron.

Biodegradation of thifensulfuron-methyl by Ochrobactrum sp. in liquid medium and soil

“…These results suggest that the percent removal of herbicide decreased with increasing amount of strain ZWS16. Similar results have been reported for degradation of sulfonylurea herbicides Zhang et al 2012). …”

“…The optimal temperatures for degradation of nicosulfuron by S. marcescens N80 were 30-35°C, and the percent degradation decreased when the temperature was lower than 20-30°C or higher than 40°C (Zhang et al 2012). The percent degradation of pyrazosulfuron-ethyl at 28°C was faster than that at 20 and 37°C by Pseudomonas sp., whereas the highest percent degradation for Bacillus sp.…”

Hydrolysis of nicosulfuron under acidic environment caused by oxalate secretion of a novel Penicillium oxalicum strain YC-WM1

“…For instance, strain BW30 was capable of converting glucose (or other carbon compounds in soil) into short-chain fatty acids, including oxalic and lactic acids. These short-chain fatty acids then attacked the sulfonylurea bridge and finally resulted in the breakdown of TBM molecules 37 . In our study, glucose metabolism was essential to nicosulfuron degradation by Penicillium oxalicum YC-WM1.…”

Persistence of the Sulfonylurea Herbicides Sulfosulfuron, Rimsulfuron, and Nicosulfuron in Farm Dugouts (Ponds)

“…In addition, high concentrations of dissolved organic C (Arts et al, 2000; mean concentrations of 11.9 to 17.6 mg L −1 ; Supplemental Table S1) and ice cover in winter, both of which are characteristic of prairie surface waters, would have reduced photodegradation in the current study through attenuation of ultraviolet light. Microbial degradation of sulfosulfuron has been reported in soil (Brar et al, 2006), and rimsulfuron (Zhang et al, 2012) and nicosulfuron (Song et al, 2013; Zhang et al, 2012) have been shown to be microbially degraded in aqueous media. Thus, biotic degradation of these herbicides may have contributed to their dissipation in the water column of the dugouts in the current study (Fig.…”