ANALYSIS OF THE AMYLOLYTIC ENZYME-SYSTEM OF CLOSTRIDIUM-THERMOSULFUROGENES EM1 - PURIFICATION AND SYNERGISTIC ACTION OF PULLULANASES AND MALTOHEXAOSE FORMING ALPHA-AMYLASE

During growth of C thermosulfuogenes EM1 on starch, seven forms of pullulanase and one form of alpha-amylase were detected after gel electrophoretic separation of proteins. By determining the isoelectric points and N-terminal sequences of various pullulanase species it was evident that no structural differences exist between these proteins. These pullulanases hydrolyzed alpha-1,4- and alpha-1,6-linkages in various soluble sugar polymers causing their breakdown to maltose and maltotriose. Unlike these enzymes, the alpha-amylase produced by C. thermosulfurogenes EM1 preferentially attacked non-soluble starch. The main product of hydrolysis was maltohexaose. The combined action of pullulanases and alpha-amylase on native starch showed synergistic effect. This synergistic effect was not observed if soluble starch was used as substrate.