title: A novel tannase from the xerophilic fungus Aspergillus niger GH1.
abstract: Aspergillus niger GH1 previously isolated and identified by our group as a wild tannase producer was grown under solid-state (SSC) and submerged culture (SmC) conditions to select the enzyme production system. For tannase purification, extracellular tannase was produced under SSC using polyurethane foam as the inert support. Tannase was purified to apparent homogeneity by ultrafiltration, anion-exchange chromatography, and gel filtration that led to a purified enzyme with a specific activity of 238.14 IU/mg protein with a final yield of 0.3% and a purification fold of 46. Three bands were found on the SDS-PAG with molecular masses of 50, 75, and 100 kDa. PI of 3.5 and 7.1% Nglycosylation were noted. Temperature and pH optima were 60 degrees and 6.0 [methyl 3,4,5-trihydroxybenzoate (MTB) as substrate], respectively. Tannase was found with a KM value of 0.41 x 10-4 M and the value of Vmax was 11.03 micromoL/min at 60 degrees for MTB. Effects of several metal salts, solvents, surfactants, and typical enzyme inhibitors on tannase activity were evaluated to establish the novelty of the enzyme. Finally, the tannase from A. niger GH1 was significantly inhibited by PMSF (phenylmethylsulfonyl fluoride), and therefore, it is possible to consider the presence of a serine or cysteine residue in the catalytic site.
authors.affiliation: Food Research Department, School of Chemistry, Universidad Autonoma de Coahuila, Blvd. Venustiano Carranza and J. Cardenas s/n, ZIP 25280, Saltillo, Coahuila, Mexico.
authors.forename: Marco
authors.initials: M
authors.lastname: Mata-Gomez
authors.forename: Luis V
authors.initials: LV
authors.lastname: Rodriguez
authors.forename: Erika L
authors.initials: EL
authors.lastname: Ramos
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Renovato
authors.forename: Mario A
authors.initials: MA
authors.lastname: Cruz-Hernandez
authors.forename: Raul
authors.initials: R
authors.lastname: Rodriguez
authors.forename: Juan
authors.initials: J
authors.lastname: Contreras
authors.forename: Cristobal N
authors.initials: CN
authors.lastname: Aguilar
mesh_terms: D001234:Aspergillus niger / Q000166:cytology / Q000201:enzymology* / Q000254:growth & development; D002265:Carboxylic Ester Hydrolases / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D002850:Chromatography, Gel / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D003470:Culture Media; D005656:Fungal Proteins / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D013501:Surface-Active Agents / Q000494:pharmacology; D014462:Ultrafiltration / Q000379:methods
chemical_list: D003470:Culture Media; D005656:Fungal Proteins; D013501:Surface-Active Agents; D002265:Carboxylic Ester Hydrolases; C022711:tannase