Biodegradation of cyromazine by melamine-degrading bacteria

Biodegradation of cyromazine was investigated in liquid cultures using three melamine-degrading bacteria Arthrobacter sp. MCO, Arthrobacter sp. CSP and Nocardioides sp. ATD6. Experiments were performed aerobically in a mineral medium with glucose as a carbon source and cyromazine as the sole nitrogen source. All three strains of bacteria degraded cyromazine. Cyromazine at 23 mg/L completely disappeared by Arthrobacter sp. MCO within 7 days. The bacterial density of all three strains increased with degradation of the cyromazine. The cyromazine metabolite N-cyclopropylammeline was detected and identified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). This is the first report on the use of Arthrobacter sp. and Nocardioides sp. for cyromazine degradation and the occurrence of bacterial growth with cyromazine degradation. (C) Pesticide Science Society of Japan