Biobegradation and metabolic mechanism of cyprodinil by strain Acinetobacter sp. from a contaminated-agricultural soil in China

Using sequential soil and liquid culture enrichments with cyprodinil as the sole carbon source, a Gram-negative cyprodinil-degrader from cyprodinil-polluted agricultural soil was isolated. The sequencing analysis of 16 S rRNA indicated that the strain showed 99% homology to Acinetobacter sp. The strain could effectively degrade cyprodinil at the neutral condition. At the initial concentrations of 10, 20, 50, 100, 150 and 200 mg L−1 in minimal medium, cyprodinil was degraded by 10, 20, 49.3, 64.2, 57 and 24 mg L−1 within 14 days, respectively. Two metabolites (4-cyclopropyl-6-methyl-2-pyrimidpyridine amine and monohydroxylated para-substitution) were identified using high performance liquid chromatography tandem quadrupole time-of-flight mass spectrometry (HPLC-QTOF-MS/MS). A biodegradation pathway involving imines hydrolysis and monohydroxyl substitution on benzene ring was proposed on basis of the identified metabolites. Acinetobacter sp. would have a potential application in bioremediation of cyprodinil-contaminated soil, and the strain might have important implications in detoxification and bioremediation of pyrimidine analogues.