College of Resource and Environment, Jilin Agricultural University, Changchun, People's Republic of China.
J Environ Sci Health B. 2012;47(3):153-60. doi: 10.1080/03601234.2012.632249.
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.
通过对工业污水处理池污泥的富集培养，我们分离到一株高效的烟嘧磺隆降解菌——粘质沙雷氏菌 N80。在液体培养基中，粘质沙雷氏菌 N80 以烟嘧磺隆为唯一氮源生长，其最适降解温度、pH 值和接种量分别为 30-35°C、6.0-7.0 和 3.0%（v/v）。在初始浓度为 10 mg L⁻¹时，96 小时的降解率达到 93.6%；当初始浓度高于 10 mg L⁻¹时，随着烟嘧磺隆浓度的增加，生物降解率降低；当浓度达到 400 mg L⁻¹时，降解率仅为 53.1%。在 5 mg L⁻¹至 50 mg L⁻¹浓度范围内，降解符合农药降解动力学方程。通过液相色谱/质谱（LC/MS）鉴定代谢产物表明，烟嘧磺隆的降解是通过破坏磺酰脲桥实现的。菌株 N80 还能降解其他一些磺酰脲类除草剂，包括乙氧嘧磺隆、噻吩磺隆、甲基咪草烟、甲磺胺隆和啶嘧磺隆。
