Effect of different immobilization techniques on α- amylase

Immobilization has emerged since last decade as a very powerful tool to improve almost all enzyme properties like stability, activity, specificity and selectivity, and reduction of inhibition. The immobilization may help to solve some of the problems of enzymes as industrial biocatalysts like enzyme recovery for reuse. In the present investigation A.niger was isolated from soil and identified by lactophenol staining and microscope observation. Amylase producing A.niger were screened using starch hydrolysis medium. αamylase enzyme assay was done by DNS method. Immobilization was performed using entrapment method. The Entrapment materials were polyacrylamide, agar-agar, and gelatin and caalginate. Different matrix was immobilized with amylase and the fermentation period was noted as 36, 72, 108, 144, 180, 216 hrs. Immobilized microbes were subjected to growth in production medium and enzyme activity was noted as every 36 hrs. The 36 hrs sample was subjected to Folin’s Lowry procedure to determine the activity of amylase being released by the immobilized cells. The O.D reading was done by periodic sample obtained from the immobilized cell media were noted. Immobilization efficiency was found to be highest for polyacrylamide matrix 76.9% followed caalginate (57%), agaragar (33%), and gelatin (5.27%). Polyacrylamide was showed the maximum enzyme activity than three types of immobilized matrixes.