title: Secretion of alpha-amylase and multiple forms of glucoamylase by the yeast Trichosporon pullulans.
abstract: Trichosporon pullulans IGC 3488 produced extracellular alpha-amylase and glucoamylase activities when grown in batches in a medium containing corn steep liquor and soluble starch or corn starch. alpha-Amylase, unlike glucoamylase activity, was secreted biphasically. For both amylases the maximum concentration was found in stationary phase cultures. The amylolytic enzymes, previously concentrated by ammonium sulfate precipitation, were separated into a glucoamylase fraction and an alpha-amylase fraction by Ultrogel AcA 54 gel filtration. Pullulanase activity was located in the glucoamylase fraction, whereas cyclodextrinase activity was restricted to the alpha-amylase fraction. Isoamylase and alpha-glucosidase were not detected. Electrophoretic analysis showed that alpha-amylase activity was due to a single protein. Glucoamylase, however, occurred in multiple forms. The four glucoamylases and the alpha-amylase were glycoproteins.
authors.forename: R
authors.initials: R
authors.lastname: De Mot
authors.forename: H
authors.initials: H
authors.lastname: Verachtert
mesh_terms: D002850:Chromatography, Gel; D005087:Glucan 1,4-alpha-Glucosidase / Q000032:analysis / Q000378:metabolism*; D005959:Glucosidases / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism; D003904:Mitosporic Fungi / Q000201:enzymology*; D014250:Trichosporon / Q000201:enzymology* / Q000254:growth & development; D000516:alpha-Amylases / Q000032:analysis / Q000378:metabolism*
chemical_list: D005959:Glucosidases; D006026:Glycoside Hydrolases; D000516:alpha-Amylases; D005087:Glucan 1,4-alpha-Glucosidase; C100181:pullulanase; C048745:cyclomaltodextrinase