Biodegradation of Pendimethalin by Paracoccus sp P13

In this study, a bacterial strain P13 capable of degrading pendimethalin was isolated from the soil of a fruit garden. Based on observed cellular morphology and physiology characteristics and a phylogenetic analysis of 16S rRNA gene sequences, strain P13 was identified as a member of the genus Paracoccus. Strain P13 grew on pendimethalin as the sole carbon source, and could degrade 100 mg/L pendimethalin within 2 days and 200 mg/L pendimethalin within 5 days. Pendimethalin degradation was proposed to be initiated by oxidation ring cleavage to yield 1,3-dinitro-2-(pentan-3-ylamino)butane-1,4-diol, an alkane organic compound that was identified by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), which then underwent a series of enzymatic reactions to produce CO2 and H2O. The optimal pH and temperature for pendimethalin degradation by strain P13 were 7.0 and 30 degrees C, respectively. This study identified the bacterial strain Paracoccus sp. P13, which degraded pendimethalin with a relatively high efficiency, and presents a previously unreported microbial pendimethalin degradation pathway.