title: New and simple plate test for screening relative transfructosylation activity of fungi.
abstract: Several microorganisms are reported to have transfructosylation activity due to fructosyltransferase and/or fructofuranosidase activities. However, the search for other fungi with higher transfructosylation activity remains a challenge. So, a presumptive and indirect colorimetric plate assay for the evaluation of transfructosylation activity in fungi was developed which involved the simultaneous determination in the same plate of glucose and fructose released from sucrose. The method entailed the (a) glucose oxidase-peroxidase coupled reaction using phenol and 4-aminoantipyrine for determination of glucose; and (b) fructose dehydrogenase oxidation in the presence of a tetrazolium salt for determination of fructose. The presence of enzymes with transfructosylation activity was identified by the formation of pink (presence of glucose) and blue (presence of fructose) halos around the fungal colony. In conclusion, the results showed that the method is suitable for screening a large number of fungi due to its simplicity, reproducibility and rapidity and also gives a relative quantitative idea of the transfructosylation activity of different fungi species.
authors.affiliation: Centro de Engenharia Biológica, Universidade do Minho, Campus de Braga, Portugal.
authors.forename: Ana
authors.initials: A
authors.lastname: Dominguez
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Santos
authors.forename: José A
authors.initials: JA
authors.lastname: Teixeira
authors.forename: Nelson
authors.initials: N
authors.lastname: Lima
mesh_terms: D000675:Ampyrone; D001203:Ascomycota / Q000201:enzymology; D002237:Carbohydrate Dehydrogenases / Q000378:metabolism; D002863:Chromogenic Compounds / Q000032:analysis; D003124:Colorimetry / Q000295:instrumentation / Q000379:methods*; D005632:Fructose / Q000378:metabolism; D005656:Fungal Proteins / Q000032:analysis*; D005658:Fungi / Q000201:enzymology* / Q000302:isolation & purification; D005947:Glucose / Q000378:metabolism; D005949:Glucose Oxidase / Q000378:metabolism; D006031:Glycosylation; D006602:Hexosyltransferases / Q000032:analysis*; D007202:Indicators and Reagents; D007218:Industrial Microbiology / Q000295:instrumentation / Q000379:methods*; D008773:Methylphenazonium Methosulfate; D009172:Mycology / Q000295:instrumentation / Q000379:methods*; D009844:Oligosaccharides / Q000096:biosynthesis; D009195:Peroxidase / Q000378:metabolism; D019800:Phenol; D015203:Reproducibility of Results; D013045:Species Specificity; D013778:Tetrazolium Salts; D013844:Thiazoles; D043324:beta-Fructofuranosidase / Q000032:analysis*; D001426:Bacterial Proteins
chemical_list: D000675:Ampyrone; D002237:Carbohydrate Dehydrogenases; D002863:Chromogenic Compounds; D005632:Fructose; D005656:Fungal Proteins; D005947:Glucose; D005949:Glucose Oxidase; D006602:Hexosyltransferases; D007202:Indicators and Reagents; D008773:Methylphenazonium Methosulfate; D009844:Oligosaccharides; D009195:Peroxidase; D019800:Phenol; D013778:Tetrazolium Salts; D013844:Thiazoles; D043324:beta-Fructofuranosidase; C116580:fructooligosaccharide; C028761:D-fructose 5-dehydrogenase; C021451:inulosucrase; D001426:Bacterial Proteins; C022616:thiazolyl blue