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 °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.