title: Cloning and characterization of a modular GH5 β-1,4-mannanase with high specific activity from the fibrolytic bacterium Cellulosimicrobium sp. strain HY-13.
abstract: The gene (1272-bp) encoding a β-1,4-mannanase from a gut bacterium of Eisenia fetida, Cellulosimicrobium sp. strain HY-13 was cloned and expressed in Escherichia coli. The recombinant β-1,4-mannanase (rManH) was approximately 44.0 kDa and has a catalytic GH5 domain that is 65% identical to that of the Micromonospora sp. β-1,4-mannosidase. The enzyme exhibited the highest catalytic activity toward mannans at 50 °C and pH 6.0. rManH displayed a high specific activity of 14,711 and 8498 IU mg⁻¹ towards ivory nut mannan and locust bean gum, respectively; however it could not degrade the structurally unrelated polysaccharides, mannobiose, or p-nitrophenyl sugar derivatives. rManH was strongly bound to ivory nut mannan, Avicel, chitosan, and chitin but did not attach to curdlan, insoluble oat spelt xylan, lignin, or poly(3-hydroxybutyrate). The superior biocatalytic properties of rManH suggest that the enzyme can be exploited as an effective additive in the animal feed industry.
authors.affiliation: Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors.forename: Do Young
authors.initials: DY
authors.lastname: Kim
authors.forename: Su-Jin
authors.initials: SJ
authors.lastname: Ham
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: Lee
authors.forename: Han-Young
authors.initials: HY
authors.lastname: Cho
authors.forename: Ji-Hoon
authors.initials: JH
authors.lastname: Kim
authors.forename: Yi-Joon
authors.initials: YJ
authors.lastname: Kim
authors.forename: Dong-Ha
authors.initials: DH
authors.lastname: Shin
authors.forename: Young Ha
authors.initials: YH
authors.lastname: Rhee
authors.forename: Kwang-Hee
authors.initials: KH
authors.lastname: Son
authors.forename: Ho-Yong
authors.initials: HY
authors.lastname: Park
mesh_terms: D000192:Actinomycetales / Q000201:enzymology*; D000818:Animals; D001483:Base Sequence; D002384:Catalysis; D002846:Chromatography, Affinity; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli; D005685:Galactans / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008351:Mannans / Q000378:metabolism; D008361:Mannosidases / Q000235:genetics*; D008969:Molecular Sequence Data; D009835:Oligochaeta / Q000382:microbiology*; D053149:Plant Gums / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013696:Temperature
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011994:Recombinant Proteins; D008361:Mannosidases; C017471:locust bean gum