Picolinic acid (PA) is a typical mono-carboxylated pyridine derivative produced by human/animals or microorganisms which could be served as nutrients for bacteria. Most strains are pathogens causing pertussis or respiratory disease in humans and/or various animals. Previous studies indicated that strains harbor the PA degradation gene cluster. However, the degradation of PA by strains remains unknown. In this study, a reference strain of genus , RB50, was investigated. The organization of gene cluster of strain RB50 was found to be similar with that of , in which the sequence similarities of each Pic proteins are between 60% to 80% except for PicB2 (47% similarity). The 3,6-dihydroxypicolinic acid (3,6DHPA) decarboxylase gene (, designated as ) of strain RB50 was synthesized and over-expressed in BL21(DE3). The PicC showed 75% amino acid similarities against known PicC from . The purified PicC can efficiently transform 3,6DHPA to 2,5-dihydroxypyridine. The PicC exhibits optimal activities at pH 7.0, 35 °C, and the and values of PicC for 3,6DHPA were 20.41 ± 2.60 μM and 7.61 ± 0.53 S, respectively. The present study provided new insights into the biodegradation of PA by pathogens of spp.
