title: Penicillium purpurogenum produces a highly stable endo-β-(1,4)-galactanase.
abstract: The polysaccharides of galactose present in the pectin of the plant cell wall are degraded by endo-β-1,4-galactanases. The filamentous fungus Penicillium purpurogenum, which grows on a number of natural carbon sources, among them sugar beet pulp which contains pectin, has a gene (ppgal1) coding an endo-β-1,4-galactanase (PpGAL1). This enzyme was expressed heterologously in Pichia pastoris. It has a molecular mass of 38 kDa, a pH optimum of 4-4.5, and an optimal temperature of 60 °C. It is 100 % stable for up to 24 h at pH 4-4.5 and 40 °C. These stability properties, which exceed those from other endo-β-1,4-galactanases reported to date, make it particularly suitable for industrial processes requiring acidic conditions and temperatures up to 40 °C. PpGAL1 is, therefore, a potentially effective tool in the food industry and in other biotechnological applications.
authors.affiliation: Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile.
authors.forename: Vasni
authors.initials: V
authors.lastname: Zavaleta
authors.affiliation: Departamento de Ciencias Biológicas, Universidad Andrés Bello, Santiago, Chile. jeyzaguirre@unab.cl.
authors.forename: Jaime
authors.initials: J
authors.lastname: Eyzaguirre
mesh_terms: D000595:Amino Acid Sequence; D001709:Biotechnology; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D004795:Enzyme Stability; D006026:Glycoside Hydrolases / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007221:Industry; D010407:Penicillium / Q000201:enzymology*; D010802:Phylogeny; D011401:Promoter Regions, Genetic / Q000235:genetics; D011994:Recombinant Proteins / Q000302:isolation & purification; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D011994:Recombinant Proteins; D006026:Glycoside Hydrolases; C094192:arabinogalactan endo-1,4-beta-galactosidase
keywords: Endo-β-1,4-galactanase; Heterologous expression; Penicillium purpurogenum; Pichia pastoris; Thermostability