title: Biochemical characterization of thermostable β-1,4-mannanase belonging to the glycoside hydrolase family 134 from Aspergillus oryzae.
abstract: A β-1,4-mannanase, termed AoMan134A, that belongs to the GH 134 family was identified in the filamentous fungus Aspergillus oryzae. Recombinant AoMan134A was expressed in Pichia pastoris, and the purified enzyme produced mannobiose, mannotriose, mannotetraose, and mannopentaose from galactose-free β-mannan, with mannotriose being the predominant reaction product. The catalytic efficiency (kcat/Km) of AoMan134A was 6.8-fold higher toward galactomannan from locust bean gum, than toward galactomannan from guar gum, but similar toward galactomannan from locust bean gum and glucomannan from konjac flour. After incubation at 70°C for 120 min, the activity of AoMan134A toward glucomannan decreased to 50% of the maximal activity at 30°C. AoMan134A retained 50% of its β-1,4-mannanase activity after heating at 90°C for 30 min, indicating that AoMan134A is thermostable. Furthermore, AoMan134A was stable within a neutral-to-alkaline pH range, as well as exhibiting stability in the presence of a range of organic solvents, detergents, and metal ions. These findings suggest that AoMan134A could be useful in a diverse range of industries where conversion of β-mannans is of prime importance.
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Kiyota
authors.initials: K
authors.lastname: Sakai
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Mai
authors.initials: M
authors.lastname: Mochizuki
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Miyuki
authors.initials: M
authors.lastname: Yamada
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Yuta
authors.initials: Y
authors.lastname: Shinzawa
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Miho
authors.initials: M
authors.lastname: Minezawa
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Saran
authors.initials: S
authors.lastname: Kimoto
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Murata
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Kaneko
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Saaya
authors.initials: S
authors.lastname: Ishihara
authors.affiliation: Faculty of Science and Technology, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Sadanari
authors.initials: S
authors.lastname: Jindou
authors.affiliation: Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Aichi, 464-8601, Japan.
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Kobayashi
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Kato
authors.affiliation: Faculty of Agriculture, Meijo University, Nagoya, Aichi, 468-8502, Japan. moshimi@meijo-u.ac.jp.
authors.forename: Motoyuki
authors.initials: M
authors.lastname: Shimizu
mesh_terms: D000595:Amino Acid Sequence; D001236:Aspergillus oryzae / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004795:Enzyme Stability; D005685:Galactans / Q000378:metabolism; D005690:Galactose / Q000031:analogs & derivatives; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000145:classification* / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology; D007700:Kinetics; D008351:Mannans / Q000737:chemistry / Q000378:metabolism; D053149:Plant Gums / Q000378:metabolism; D013379:Substrate Specificity; D013696:Temperature; D044902:beta-Mannosidase / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; C012990:galactomannan; D006026:Glycoside Hydrolases; D044902:beta-Mannosidase; C017471:locust bean gum; D005690:Galactose
keywords: Glycoside hydrolase 134; Hemicellulose; Industrial application; Mannanolytic enzyme; Plant biomass