ENHANCING PRODUCTION OF ORGANIC ACIDS BY IMMOBILIZED THERMOPHILIC NITRILASE OF PSEUDOMONAS SP. KNB2

Abstract

Nitrile compounds have a very diverse range of application in the production of organic acid and other chemicals. Nitrilase can hydrolyze nitriles into respective organic acid and ammonia.The wide distribution and potential of producing useful products with high commercial value, present it as a green catalyst from the view point of industrial biotechnological application.A previously isolated strain of bacteria with high thermophilic nitrilase activity was characterized using biochemical tests, which showed the present belonged to Pseudomonas genus and named Pseudomonas sp. KNB2. With the aim to increase the production of organic acids cells were immobilized using calcium alginate and polyacrylamide entrapment. Calcium alginate gives maximum activity with 0.6mg cell density per bead while polyacrylamide at 0.7 mg cells per bead. The immobilized cells show optimum activity at a range of 45-600C, 6-8 pH using benzonitrile substrate at a concentration from 30mM to 50mM. The immobilized beads have stability up to 3 days and can be used up to 8-9 times. Use of metal ions such as Zn, Ag and Fe resulted in the decrease of activity of nitrilase.