Abstract
Calcium independent and acid stable α-amylases for starch liquefaction were developed by protein engineering. Termamyl LCTM obtained by site-directed mutagenesis showed high calcium independence, and its performance in the absence of calcium is equal to the one with TermamylTM in the presence of 40ppm of calcium. Termamyl LCTM was further developed by random mutagenesis, and highly improved variants have been efficiently produced by recent protein engineering technologies.
The development of detergent α-amylase began with microbial screening, and two α-amylases active and stable in alkaline conditions were identified. Those amylases were further developed by protein engineering (site-directed mutagenesis), resulting in variants with improved alkaline stability and calcium independence.
