Nitrilase induction and characterization from a newly isolated Stenotrophomonas maltophilia AC21 and its application for bench scale production of nicotinic acid from 3-cyanopyridine

Publication date: Available online 21 November 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Arastoo Badoei-Dalfard, Zahra Karami, Narjes Ramezani-pour A novel bacterial named AC21 having nitrile-converting activity was gained with acetonitrile as sole source of nitrogen, which was recognized by morphology and 16S rDNA gene sequence as Stenotrophomonas maltophilia. This intracellular nitrilase induced by acetonitrile (0.3%) catalyses the conversion of 3-cyanopyridine to nicotinic acid without noticeable production of nicotinamide. Optimal pH and temperature of Nitrilase AC21 was obtained at pH 8.0 and 45°C. Irreversible thermo-inactivation results showed that, enzyme half-life was 6h at 80°C. Several process factors, including quantity of enzyme and rate of substrate feeding, were considered with the goal of reaching whole substrate transformation. In a fed batch manner at 1L scale using hyper-induced AC21 resting cells equivalent to 10Uml−1 nitrilase activity, a total of 945mM of 3-cyanopyridine was formed at a rate of 3.32g h−1 gdcw−1, which directed AC21 has ability of application in large scale nicotinic acid production. Graphical abstract
Source: Journal of Molecular Catalysis B: Enzymatic - Category: Biochemistry Source Type: research