Some Properties of Free and Immobilized α‐Amylase from Penicillium griseofulvum by Solid State Fermentation

Abstract

α‐Amylase was produced from Penicillium griseofulvum by an SSF technique. α‐Amylase was immobilized on Celite by an adsorption method. Various parameters, such as effect of pH and temperature, substrate concentration, operational and storage stability, ability to hydrolyze starch and products of hydrolysis were investigated; these findings were compared with the free enzyme. The activity yield of immobilization was 87.6%. The optimum pH and temperature for both enzymes were 5.5°C and 40°C, respectively. The thermal, and the operational and storage stabilities of immobilized enzyme were better than that of the free enzyme. K_m and V_max were calculated from Lineweaver–Burk plots for both enzymes. K_m values were 9.1 mg mL⁻¹ for free enzyme, and 7.1 mg mL⁻¹ for immobilized enzyme. The V_max of the immobilized enzyme was approximately 40% smaller than that of the free enzyme. The hydrolysis ability of the free and immobilized enzyme were determined as 99.3% and 97.9%, respectively. Hydrolysis products of the α‐amylase from P. griseofulvum were maltose, unidentified oligosaccharides, and glucose.

Keywords:

• α‐Amylase
• Penicillium griseofulvum
• Celite
• Immobilization
• SSF
• Starch