| 摘要 |
PROBLEM TO BE SOLVED: To obtain a new ultra heat-resistant and ultra acid-resistant amylopullulanase capable of hydrolyzing both α-1,4-glucoside bond and α-1,6-glucoside bond, and useful for producing glucose or the like. SOLUTION: This amylopullulanase is derived from an ultra thermophilic bacterium belonging to the genus Desulfurococcus such as Z-3 strain (FERM P-16602), and has the following physicochemical properties: (i) hydrolyzing both α-1,4-glucoside bond and α-1,6-glucoside bond; (ii) exhibiting a molecular weight of 70 kDa in SDS-PAGE and 45 kDa in gel filtration; (iii) having the optimum pH of 5.0 and having an activity at pH 4.0 of 70% or more of the activity at the optimum pH; and (iv) having the optimum temperature of 100 deg.C, and having a residual activity of 90% or more after incubation for 30 min in the absence of CaCl2 at pH 5.0 and a temperature of 90 deg.C or more. Further, the ultra heat-resistant and ultra acid-resistant amylopullulanase and a slurry of starch are preferably incubated to produce glucose. |
