title: Purification and characterization of an aflatoxin degradation enzyme from Pleurotus ostreatus.
abstract: Nineteen fungi were tested for their ability to degrade aflatoxin B1 (AFB1). An extracellular enzyme from the edible mushroom Pleurotus ostreatus showed afaltoxin-degradation activity detected by thin-layer chromatography (TLC). An enzyme with this activity was purified by two chromatographies on DEAE-Sepharose and Phenyl-Sepharose. The apparent molecular mass of the purified enzyme was estimated to be 90 kDa by SDS-PAGE. Optimum activities were found in the pH range between 4.0 and 5.0 and at 25 degrees C. Also, degradation activity of several dyes in the presence of H2O2 was tested, resulting in the detection of bromophenol blue-decolorizing activity. Based on these data, we suggest this enzyme is a novel enzyme with aflatoxin-degradation activity. Fluorescence measurements suggest that the enzyme cleaves the lactone ring of aflatoxin.
authors.affiliation: Department of Biological and Chemical Engineering, Faculty of Engineering, Gunma University, Kiryu, Gunma 376-8515, Japan.
authors.forename: Marisa
authors.initials: M
authors.lastname: Motomura
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Toyomasu
authors.forename: Keiko
authors.initials: K
authors.lastname: Mizuno
authors.forename: Takao
authors.initials: T
authors.lastname: Shinozawa
mesh_terms: D016604:Aflatoxin B1 / Q000378:metabolism*; D001978:Bromphenol Blue / Q000378:metabolism; D002845:Chromatography; D004591:Electrophoresis, Polyacrylamide Gel; D004798:Enzymes / Q000302:isolation & purification* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D020076:Pleurotus / Q000201:enzymology*; D013053:Spectrophotometry; D013696:Temperature
chemical_list: D004798:Enzymes; D001978:Bromphenol Blue; D016604:Aflatoxin B1