3 DIFFERENT TYPES OF ALPHA-AMYLASES FROM ASPERGILLUS-AWAMORI KT-11 - THEIR PURIFICATIONS, PROPERTIES, AND SPECIFICITIES

Three forms of alpha-amylases, designated Amyl I, Amyl II, and Amyl II I were purified to a homogenous state by several column chromatographi es from a koji culture in wheat bran of a strain of black mold, which was isolated in Indonesia and identified as Aspergillus awamori. They have molecular weights of 49,000, 63,000, and 97,000 by SDS-PAGE, resp ectively, and the optimum pHs were 4.0 for Amyl I and 5.5 for both Amy l II and Amyl III on soluble starch. Amyl I hydrolyzed malto-tetraose, -pentaose, -hexaose, -heptaose, and beta- and gamma-cyclodextrin to p roduce maltose and maltotriose as major products but not or hardly hyd rolyzed maltose, isomaltose, maltotriose, isomaltotriose, alpha-cyclod extrin, or raw corn starch. On the other hand, both Amyl II and Amyl L II hydrolyzed maltotriose as well as all the maltooligosaccharides des cribed above and alpha-, beta-, and gamma-cyclodextrin, and even raw c orn starch as well as heat-gelatinized corn starch to produce maltose as a major product and glucose and maltotriose as minor products, but they did not hydrolyze maltose, isomaltose, or isomaltotriose. The lim it hydrolyses of soluble starch with three kinds of enzymes were 33% f or Amyl I, 35% for Amyl II, and 38% for Amyl III, the reaction product s had alpha-anomeric forms by NMR analysis, and the blue color reactio n with I-2 disappeared completely at about 18% of hydrolysis of the st arch for all enzymes.