Expression and characterization of amylase encoded by a gene cloned from Cellulomonas sp. NCIM 2353

A Cellulomonas genomic fragment encoding extracellular amylase activity was isolated as a clone (ACs2) in Escherichia coli DH10B. The amylase was expressed in the absence of IPTG and in the presence of starch or maltose. This enzyme corresponded to the low mobility activity of Cellulomonas amylases as demonstrated on gel electrophoresis. Maltose, as well as lactose, xylose and xylan cross-induced the amylase of clone ACs2. Maltose-induced amylase was purified to homogeneity. ACs2-coded amylase is a 70kDa acidic protein, with a pH optimum of 7.0 at 45°C. This enzyme exhibited an endo mode of action, similar to the corresponding Cellulomonas enzyme.