Influence of immobilization on biocatalytic activity of a microbial (Bacillus amyloliquefaciens) alpha-amylase

The aim of this study was to stabilize an enzymatic preparation with alpha-amylase activity produced by a Bacillus amyloliquefaciens strain in submerged culture. The immobilization techniques used were physical bonding on a porous ceramic support, entrapment in silica gels and entrapment/deposition on ceramics. The immobilized alpha-amylase was characterized in terms of optimal pH and temperature, pH, thermal and storage stability, kinetic parameters in the context of all used immobilization methods. The optimal temperature and pH of the native and immobilized enzymes did not vary significantly. At temperature and pH values lower than the optimum, the relative activities have been higher for the immobilized Bacillus amyloliquefaciens enzyme compared to the native one. The immobilization has led to an enzymatic compound with high stability and good catalytic efficiency, more pregnant in the case of entrapment/deposition.