title: Purification and characterization of a cold-adapted pullulanase from a psychrophilic bacterial isolate.
abstract: There is a considerable potential of cold-active biocatalysts for versatile industrial applications. A psychrophilic bacterial strain, Shewanella arctica 40-3, has been isolated from arctic sea ice and was shown to exhibit pullulan-degrading activity. Purification of a monomeric, 150-kDa pullulanase was achieved using a five-step purification approach. The native enzyme was purified 50.0-fold to a final specific activity of 3.0 U/mg. The enzyme was active at a broad range of temperature (10-50 °C) and pH (5-9). Optimal activity was determined at 45 °C and pH 7. The presence of various metal ions is tolerated by the pullulanase, while detergents resulted in decreased activity. Complete conversion of pullulan to maltotriose as the sole product and N-terminal amino acid sequence indicated that the enzyme is a type-I pullulanase and belongs to rarely characterized pullulan-degrading enzymes from psychrophiles.
authors: Institute of Technical Microbiology, Hamburg University of Technology (TUHH), Kasernenstr. 12, 21073, Hamburg, Germany.
authors: Farah
authors: F
authors: Qoura
authors: Skander
authors: S
authors: Elleuche
authors: Thomas
authors: T
authors: Brueck
authors: Garabed
authors: G
authors: Antranikian
mesh_terms: D000222:Adaptation, Physiological; D000595:Amino Acid Sequence; D001110:Arctic Regions; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D003080:Cold Temperature; D006026:Glycoside Hydrolases / Q000737:chemistry* / Q000378:metabolism; D008969:Molecular Sequence Data; D020592:Shewanella / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D006026:Glycoside Hydrolases; C100181:pullulanase