Effect of temperature on some characteristics of the thermostable α-amylase from Bacillus licheniformis.

The V max of an extracellular, thermostable α-amylase from Bacillus licheniformis 44MB82 were 5.70×10(-3) and 9.70×10(-3) MM s(-1) at 30 and 90°C, respectively, whereas the K m values were similar (0.9 mg ml(-1)) at both temperatures. Excluding dextrins, the dominant products from soluble starch and amylopectin hydrolysis contained less than six glucose residues. The enzyme hydrolysed amylopectin better than soluble starch. Increasing the temperature from 30 to 90°C was accompanied by an increase in the production of malto-oligosaccharides, especially maltotetrose, and this was related to the secondary hydrolysis of maltopentose and maltohexose.