Effect of agitation and aeration on the production of nitrile hydratase by Rhodococcus erythropolis MTCC 1526 in a stirred tank reactor

Abstract

To evaluate the effect of different physicochemical parameters such as agitation, aeration and pH on the growth and nitrile hydratase production by Rhodococcus erythropolis MTCC 1526 in a stirred tank reactor. Rhodococcus erythropolis MTCC 1526 was grown in 7-l reactor at different agitation, aeration and controlled pH. The optimum conditions for batch cultivation in the reactor were an agitation rate of 200 rev min(-1) , aeration 0.5 v/v/m at controlled pH 8. In this condition, the increase in nitrile hydratase activity was almost threefold compared to that in the shake flask. Agitation and aeration rate affected the dissolved-oxygen concentration in the reactor which in turn affected the growth and enzyme production. Cultivation of R. erythropolis MTCC 1526 in the reactor was found to have significant effect on the growth and nitrile hydratase production when compared to the shake flask.