Effects of reduced malto-oligosaccharides on the thermal stability of pullulanase from Bacillus acidopullulyticus.
We investigated the effects of the reduced malto-oligosaccharides, D-glucitol (G1-OH), maltitol (G2-OH), maltotriitol (G3-OH), maltotetraitol (G4-OH), and maltopentaitol (G5-OH) on the thermal stability of Bacillus acidopullulyticus pullulanase (EC 3.2.1.41). The thermal stability depended on the concentration of D-glucitol; after heat treatment for 90 min at 60 degrees in the presence of 0.56, 0.28, 0.14, or 0M G1-OH, the residual activity was 100, 80, 32, and 10% of the control, respectively. Stability increased with the number of glucosyl residues in the alditols added; the effects of G3-OH, G4-OH, and G5-OH on stability were remarkable. Addition of 30% G2-OH, G3-OH, and G4-OH also contributed to the thermal stability of the pullulanase immobilized onto chitosan beads treated with glutaraldehyde. A high concentration of G2-OH stabilized other debranching amylases, Klebsiella pneumoniae pullulanse, Bacillus sectorramus pullulanase, and Pseudomonas amyloderamosa isoamylase (EC 3.2.1.68) under heat treatment for 48 h at 60 degrees, as well as the pullullanase of B. acidopullulyticus.
Department of Agricultural Chemistry, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Japan.
S
S
Kusano
S
S
Takahashi
D
D
Fujimoto
Y
Y
Sakano
D000681:Amylases / Q000378:metabolism; D001407:Bacillus / Q000187:drug effects / Q000201:enzymology*; D055598:Chemical Phenomena; D002621:Chemistry; D004795:Enzyme Stability / Q000187:drug effects; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006358:Hot Temperature; D007711:Klebsiella pneumoniae / Q000201:enzymology; D008320:Maltose / Q000031:analogs & derivatives / Q000494:pharmacology; D009844:Oligosaccharides / Q000494:pharmacology*; D013012:Sorbitol / Q000494:pharmacology; D013379:Substrate Specificity; D013402:Sugar Alcohols / Q000494:pharmacology
D009844:Oligosaccharides; D013402:Sugar Alcohols; C021705:maltooligosaccharides; D013012:Sorbitol; D008320:Maltose; C010745:maltitol; D000681:Amylases; D006026:Glycoside Hydrolases; C100181:pullulanase