Bench-scale biosynthesis of isonicotinic acid from 4-cyanopyridine by Pseudomonas putida

Pseudomonas putida CGMCC3830 harboring nitrilase was used in isonicotinic acid production from 4-cyanopyridine. This nitrilase showed optimum activities towards 4-cyanopyridine at pH 7.5 and 45°C. The half-life of P. putida nitrilase was 93.3 h, 33.9 h, and 9.5 h at 30°C, 38°C, and 45°C, respectively. 4-Cyanopyridine (100 mM) was fully converted into isonicotinic acid within 20 min. The bench-scale production of isonicotinic acid was carried out using 3 mg of resting cells per mL in a 1 L system at 30°C and finally, 123 g L^?1 of isonicotinic acid were obtained within 200 min without any by-products. The conversion reaction suffered from the product inhibition effect after the tenth feeding. The volumetric productivity was 36.9 g L^?1 h^?1. P. putida shows significant potential in nitrile hydrolysis for isonicotinic acid production. This paper is the first report on isonicotinic acid biosynthesis using Pseudomonas putida and it represents the highest isonicotinic acid production reported so far.