Thermostable Barley Alpha-Glucosidase for Improved Ethanol Production


Barley alpha-glucosidase is an important enzyme in the conversion of barley starch to fermentable sugars during the industrial production of ethanol. However it is relatively thermolabile which is a disadvantage for an enzyme used in industrial processes at elevated temperatures. UW-Madison researchers have developed a mutant barley alpha-glucosidase with increased thermal stability. They developed thermostable forms of the enzyme using site directed mutagenesis. Sites for mutagenesis were selected through comparisons with the sequences of other more thermostable alpha-glucosidase proteins. Applications: 1) Part of a kit for assaying the quality of flour products and in any process that uses starch as a source of sugars including brewing glucose syrup production and textile and paper pulping 2) Mashing systems where nutrient broths are created for fermenting or for generating alcohol fuel from corn material


1) Mutant enzyme shows increased thermal stability of 10 to 15 degrees as compared to wild-type alpha-glucosidase. 2) Enzyme can be easily and efficiently produced in yeast.

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