The raw starch-degrading alkaline amylase of Bacillus sp IMD 370

Abstract

The amylase of Bacillus sp IMD 370 is the first report of an alkaline amylase with the ability to digest raw starch. The amylase could degrade raw corn and rice starches more effectively than raw potato starch. It showed no adsorb-ability to any type of raw starch at any pH value tested. The enzyme digested raw corn starch to glucose, maltose, maltotriose and maltotetraose. The maximum pH for raw starch hydrolysis was pH 8.0 compared to pH 10.0 for soluble starch hydrolysis. The metal chelator, ethylenediaminetetraacetic acid, strongly inhibited raw starch-digestion and its effect was reversed by the addition of divalent cations. Degradation of raw starch was stimulated six-fold in the presence of β-cyclodextrin (17.5 mM). © 1995 Society for Industrial Microbiology.