CALCIUM ALGINATE AS A SUPPORT MATERIAL FOR IMMOBILIZATION OF L-AMINO ACID OXIDASE ISOLATED FROM ASPERGILLUS FUMIGATUS

Crude L-amino acid oxidase (L-aao) of Aspergillus fumigatus was immobilized in various solid supports namely, entrapment in calcium alginate gel and gelatin gel, and adsorption in nylon membrane by cross linking with glutaraldehyde. Immobilization of A. fumigatus L-aao in calcium alginate gel was the most favourable since the percent entrapped activity was maximal in calcium alginate beads (31.77%) as compared to the adsorption in nylon membrane (26.88%). Maximum enzyme activity was found with 3 % sodium alginate. Reaction time for immobilized beads increases from 2h reaching a maximum at 6h. The activity of the calcium alginate entrapped A. fumigatus L-aao beads was assayed for four cycles with DL-alanine as the substrate. The enzyme showed 87.52 % activity during the second reuse and 72.37 % activity on its third use. Immobilization in gelatin gel was ineffective since the immobilized gel cubes were unstable and disintegrated during the enzyme reaction. As for immobilization of the L-aao by adsorption in nylon membrane, only 26.88% activity was retained. Received on: 21st-Jan-2011 Revised on: 11th-May-2011 Accepted on: 16th-May-2011 Published on: 12th -Oct-2012