The development of a calcium independent a-amylase for starch liquefaction has recently been described [1]. Incorporation of 5 single amino acid substitutions and one N-terminal alteration in the B. licheniformis a-amylase resulted in an amylase able to operate without addition of calcium and at a lower pH.

Liquefaction of whole corn - a process used by the North American ethanol industry - encounters additional stability problems. The amylase had previously to be dosed at very high levels due to instability in solution with high ash and lipid levels.

The development of a novel a-amylase derived from a protein engineered strain of Bacillus stearothermophilus will be described. An enzyme that liquefies and thins mashes exceptionally well.

The novel enzyme has showed promising performance in industrial testing resulting in:

• Reduced processing costs
• Increased plant profitability
• Greater starch conversion
• Higher ethanol output
• More' forgiving' liquefaction process