Study on Optimization of Fermentation Conditions for Nitrile Hydratase Production by Rhodococcus sp.and Its Enzymological Character

The process of nitrile hydratase(NHase) produced by Rhodococcus sp.strain SHZ-1 was investigated for establishing the interrelation of cell growth,enzyme production,and effect of pH and glucose consumption on NHase activity.It was shown that pH adjustment and glucose supplement during feed batch fermentation could significantly increase cell growth and NHase activity for 1.28 fold increment from 2294 U/mL to 5226 U/mL.Nitrile hydratase was kept stable at 30 ℃ and in neutral pH solution.The influences of the substrate concentration on the enzyme activity were studied.That was shown that the optimal concentration of acrylonitrile was 7.2%.The higher concentration of the final product acrylamide,the stronger inhibitive effect exhibited on the activity of nitrile hydratase.