title: An alpha-galactosidase from an acidophilic Bispora sp. MEY-1 strain acts synergistically with beta-mannanase.
abstract: An alpha-galactosidase gene (AgalB) was cloned from the acidophilic fungus Bispora sp. MEY-1 and expressed in Pichia pastoris. The deduced amino acid sequence showed highest identity (35%) to the alpha-galactosidase from Penicillium simplicissimum, belonging to the glycosyl hydrolase family 27. The purified recombinant alpha-galactosidase (r-AgalB) exhibited optimal activity at pH 3.5 and 55 degrees C, was stable at pH 2.2-8.0, and showed higher hydrolytic activity towards galactomannan polysaccharides (guar gum and locust bean gum) than toward small galacto-oligosaccharides (melibiose, raffinose and stachyose). A synergistic (3-fold) increase in guar gum hydrolysis was observed when beta-mannanase Man5A from Bispora sp. MEY-1 and r-AgalB were combined. Further, an increase in the reaction time from 5h to 12h or increase of the temperature from 37 degrees C to 55 degrees C enhanced guar gum degradation by the enzyme combination. These properties make r-AgalB a good candidate for extensive application in the pulp/paper, food, and feed industries.
authors.affiliation: Key Laboratory for Feed Biotechnology of the Ministry of Agriculture, Feed Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.forename: Huiying
authors.initials: H
authors.lastname: Luo
authors.forename: Jiang
authors.initials: J
authors.lastname: Li
authors.forename: Yingguo
authors.initials: Y
authors.lastname: Bai
authors.forename: Huoqing
authors.initials: H
authors.lastname: Huang
authors.forename: Pengjun
authors.initials: P
authors.lastname: Shi
authors.forename: Yunliu
authors.initials: Y
authors.lastname: Fan
authors.forename: Bin
authors.initials: B
authors.lastname: Yao
mesh_terms: D001203:Ascomycota / Q000201:enzymology*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D005685:Galactans / Q000378:metabolism; D006868:Hydrolysis; D008351:Mannans / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D053149:Plant Gums / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D000519:alpha-Galactosidase / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D044902:beta-Mannosidase / Q000378:metabolism*
chemical_list: D005685:Galactans; D008351:Mannans; D053149:Plant Gums; D011994:Recombinant Proteins; C007894:guar gum; D000519:alpha-Galactosidase; D044902:beta-Mannosidase