Development of Bed Reactor Using Brick Dust Immobilized CM-Cellulase from Seeds of Cowpea (Vigna sinensis L)

Cellulase extracted from seeds of cowpea (Vigna sinensis L var VITA-4) was partially purified and immobilized on brick dust as solid support via glutaraldehyde. The percentage retention of the enzyme activity on brick dust was nearly 85%. After immobilization specific activity of the enzyme increased from 0.275 to 0.557 U mg⁻¹ protein with about 2 fold enrichment. The optimum pH and temperature of soluble enzyme were determined as pH 4.6 and 35°C, respectively whereas immobilized enzyme showed at pH 5.0 and 37°C, respectively. The V_max values for soluble and immobilized enzyme were determined as 6.67 and 1.25 mg min⁻¹, respectively whereas K_m values were 4.35 and 4.76 mg ml⁻¹, respectively. The immobilized enzyme displayed higher thermal stability than soluble enzyme and retained about 50% of its initial activity after 12 reuses. Immobilized enzyme was packed in an indigenously designed double walled glass bed reactor for continuous production of reducing sugars.