Amylase production by Aspergillus flavus immobilized in polysaccharide beads of Adansonia digitata.

Abstract

A novel matrix for the immobilization of amylase produced by Aspergillus flavus was exploited in this study. Spores of A. flavus were immobilized on Adansonia digitata matrix cross-linked with glutaraldehyde (2.5 %) and the effects of gel concentration (9 – 13 %), spore load (100 – 500 mg), bead size (2 - 7 mm) and bead number (2 - 10) on amylase activity were determined. Optimum amylase activity of 280 U/ml was obtained under batch fermentation at 10 % gel concentration, 280 mg spore load with 9 beads of 3.0 mm bead size at 96 h of fermentation compared to 190 U/ml by the free cells. The immobilized A. flavus retained amylase activity of 250 U/ml after four repeated cycle and also exhibited increased activities over the free cells. This study shows the potential of Adansonia digitata as a novel matrix for increased amylase production.