Submitted to: Green Chemistry
Publication Type: Abstract Only
Publication Acceptance Date: 6/26/2007
Publication Date: 6/26/2007
Citation: Stevenson, D.G., Inglett, G.E. 2007. Alpha-amylase activity in various concentrations of the ionic liquid, 1-butyl-3-methylimidazolium chloride [abstract]. Green Chemistry. p. 58. Interpretive Summary:
Technical Abstract: Starch is an extremely abundant, economical and versatile industrial commodity. Many industrial uses of starch depend on hydrolyzing the polymer for the conversion of glucose and maltodextrins. Starch hydrolysis is frequently achieved by utilizing alpha-amylase, which is an endo-acting enzyme that hydrolyzes alpha-1,4 glucosidic linkages. Widely misunderstood, starch is in fact very insoluble without heat, and applying heat above gelatinization temperature does not effectively disperse all starch molecules. Organic solvents such as dimethyl sulfoxide disperse starch efficiently but there are toxicity issues. We have already demonstrated that environmentally friendly ionic liquids can be extremely useful for dispersing starch when heated, with much clearer solutions obtained compared with water. However, it is currently unknown whether starch hydrolyzing enzymes are active in ionic liquids. We do not know if activity is unaffected in pure ionic liquids, and if activity is not maximized, we need to determine the dilution of ionic liquids that will prevent enzymic inhibition. We will present results on the activity of alpha-amylase from porcine pancreas, barley malt, Aspergillus oryzae, Bacillus amyloliquefaciens (thermostable) and Bacillus licheniformis (thermostable) in various concentrations of the ionic liquid, 1-butyl-3-methylimidazolium chloride. Understanding the activity of alpha-amylases in ionic liquids may lead to a more efficient and economical technology for hydrolyzing starch, an important application for many industrial processes.