Isolation and characterization of the 2,5-pyridinedicarboxylic acid-degrading bacterium Agrobacterium sp. strain YJ-5.

2,5-Pyridinedicarboxylic acid (2,5-PDA), a natural N-heterocyclic compound and a substitute for production in plastics, was widely distributed in industrial wastewater. However, the biodegradation of 2,5-PDA has been rarely reported. In this study, strain YJ-5, which could utilize 2,5-PDA as the sole carbon source for growth was isolated from pesticide-contaminated soil. Based on the comparative analysis of the 16S rRNA gene sequence, strain YJ-5 was identified as Agrobacterium sp. 2,5-PDA was completely degraded within 7 d and the optimal growth conditions of temperature, pH, and substrate concentration were 30°C, 7.0, and 0.6 mmol-1, respectively. A new intermediate 6-hydroxy-2,5-PDA was determined by UV/VIS spectroscopy and liquid chromatograph coupled time of flight mass spectrometry. When the electron acceptor (2,6-dichlorophenolindophenol) was employed, the 2,5-PDA could be converted by cell extracts of strain YJ-5 cells into 6-hydroxy-2,5-PDA. These results provided new insights for biodegradation on pyridine dicarboxylate.