| Abstract: | During growth of C. thermosulfurogenes EM1 on starch, seven forms of pullulanase and one form of α-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 α-1,4- and α-1,6-linkages in various soluble sugar polymers causing their breakdown to maltose and maltotriose. Unlike these enzymes, the α-amylase produced by C. thermosulfurogenes EM1 preferentially attacked non-soluble starch. The main product of hydrolysis was maltohexaose. The combined action of pullulanases and α-amylase on native starch showed synergistic effect. This synergistic effect was not observed if soluble starch was used as substrate. |
