title: A highly active endo-β-1,4-mannanase produced by Cellulosimicrobium sp. strain HY-13, a hemicellulolytic bacterium in the gut of Eisenia fetida.
abstract: A xylanolytic gut bacterium isolated from Eisenia fetida, Cellulosimicrobium sp. strain HY-13, produced an extracellular glycoside hydrolase capable of efficiently degrading mannose-based substrates such as locust bean gum, guar gum, mannotetraose, and mannopentaose. The purified mannan-degrading enzyme (ManK, 34,926 Da) from strain HY-13 was found to have an N-terminal amino acid sequence of DEATTDGLHVVDD, which has not yet been identified. Under the optimized reaction conditions of 50°C and pH 7.0, ManK exhibited extraordinary high specific activities of 7109 IU/mg and 5158 IU/mg toward locust bean gum and guar gum, respectively, while the enzyme showed no effect on sugars substituted with p-nitrophenol and various non-mannose carbohydrates. Thin layer chromatography revealed that the enzyme degraded locust bean gum to mannobiose and mannotetraose. No detectable amount of mannose was produced from hydrolytic reactions with the substrates. ManK strongly attached to Avicel, β-cyclodextrin, lignin, and poly(3-hydroxybutyrate) granules, but not bound to chitin, chitosan, curdlan, or insoluble oat spelt xylan. The aforementioned characteristics of ManK suggest that it is a unique endo-β-1,4-mannanase without additional carbohydrolase activities, which differentiates it from other well-known carbohydrolases.
authors: Industrial Bio-materials Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Daejeon 305-806, Republic of Korea.
authors: Do Young
authors: DY
authors: Kim
authors: Su-Jin
authors: SJ
authors: Ham
authors: Hyun Ju
authors: HJ
authors: Lee
authors: Yi-Joon
authors: YJ
authors: Kim
authors: Dong-Ha
authors: DH
authors: Shin
authors: Young Ha
authors: YH
authors: Rhee
authors: Kwang-Hee
authors: KH
authors: Son
authors: Ho-Yong
authors: HY
authors: Park
mesh_terms: D000192:Actinomycetales / Q000201:enzymology* / Q000254:growth & development / Q000302:isolation & purification; D000818:Animals; D003470:Culture Media / Q000737:chemistry; D004064:Digestive System / Q000382:microbiology*; D005685:Galactans / Q000378:metabolism; D006868:Hydrolysis; D008351:Mannans / Q000378:metabolism*; D008361:Mannosidases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D009835:Oligochaeta / Q000382:microbiology*; D009844:Oligosaccharides / Q000378:metabolism; D053149:Plant Gums / Q000378:metabolism
chemical_list: D003470:Culture Media; D005685:Galactans; D008351:Mannans; D009844:Oligosaccharides; D053149:Plant Gums; C014647:mannobiose; C039922:mannotetraose; C007894:guar gum; D008361:Mannosidases; C041867:endo-1,4-beta-D-mannanase; C017471:locust bean gum