Mathematically optimized production, purification and characterization of penicillin G acylase from soil bacterial isolates AA17A and AA17B

260-268This research article deals with production of industrial enzyme penicillin G acylase from soil bacterial isolates namely AA17A and AA17B, which are selected from 80 soil samples. The strains were selected based on qualitative (turbidity) and quantitative (HPLC) test for 6-aminopenicillanic acid (6APA) production. The enzyme was assayed for its activity and optimized for production of enzyme using design of experiments software (DOE) “Design Expert 8.0.7.1”. Optimization of enzyme production of four carbon sources (glucose, glycerol, sucrose and starch), four nitrogen sources (beef extract, tryptone, peptone and yeast extract), for temperature (25°C, 30°C, 35°C and 40°C), four pH (6, 7, 8, 9), four inoculum volumes (2.5 ml, 5.0 ml, 7.5 ml, 10.0 ml) and the phenyl acetic acid (PAA) level  (0.15%, 0.17%, 0.185%, 0.2%). The penicillin acylase activity was enhanced to 1.2 fold under following optimized culture conditions: carbon source - glucose (8%), nitrogen source - beef extract (2%), pH 9.0, temperature 30ºC, phenyl acetic acid 0.185%, inoculum volume 5 ml. Approximately 1.22-fold purification from the initial culture broth was achieved during ammonium sulphate precipitation (70-80%) with a yield of 4.6% enzyme. The specific activity of the final partially purified enzyme was 13.73 IU/mg protein