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

作者：Feng, Weimin; Wei, Zheng; Song, Jinlong; Qin, Qiao; Yu, Kaimin; Li, Guochao; Zhang, Jiayu; Wu, Wei; Yan, Yanchun^*

来源：Scientific Reports, 2017, 7(1): 647.

DOI：10.1038/s41598-017-00228-2

• TANDEM MASS-SPECTROMETRY
• CO-METABOLIC DEGRADATION
• SULFONYLUREA HERBICIDES
• PHOTOCATALYTIC DEGRADATION
• METSULFURON-METHYL
• TRIBENURON-METHYL
• LABORATORY CONDITIONS
• ASPERGILLUS-NIGER
• CHLORIMURON-ETHYL
• SOIL

A novel Penicillium oxalicum strain YC-WM1, isolated from activated sludge, was found to be capable of completely degrading 100 mg/L of nicosulfuron within six days when incubated in GSM at 33 degrees C. Nicosulfuron degradation rates were affected by GSM initial pH, nicosulfuron initial concentration, glucose initial concentration, and carbon source. After inoculation, the medium pH was decreased from 7.0 to 4.5 within one day and remained at around 3.5 during the next few days, in which nicosulfuron degraded quickly. Besides, 100 mg/L of nicosulfuron were completely degraded in GSM medium at pH of 3.5 without incubation after 4 days. So, nicosulfuron degradation by YC-WM1 may be acidolysis. Based on HPLC analysis, GSM medium acidification was due to oxalate accumulation instead of lactic acid and oxalate, which was influenced by different carbon sources and had no relationship to nicosulfuron initial concentration. Furthermore, nicosulfuron broke into aminopyrimidine and pyridylsulfonamide as final products and could not be used as nitrogen source and mycelium didn't increase in GSM medium. Metabolomics results further showed that nicosulfuron degradation was not detected in intracellular. Therefore, oxalate secretion in GSM medium by strain YC-WM1 led to nicosulfuron acidolysis.

• 出版日期2017-4-5
• 单位中国水产科学研究院; 中国农业科学院