2-2--azino-di-(3-ethylbenzothiazoline)-6-sulfonic-acid and 4-hydroxyphenylacetic-acid

A fluorometric procedure has been developed for detection and estimation of laccase activity in fungal broth cultures. Laccase solution was pretreated with catalase for 1 h at 37 degrees C and pH 5. Homovanillic acid was then added and the reaction mixture incubated for a further hour at 37 degrees C. The fluorescence was then developed by addition of 0.1 M glycine buffer at pH 10. Laccase preparations from Pyricularia oryzae, Coriolus hirsutus and Pycnoporus cinnabarinus catalysed formation of a fluorescent product of HVA but the optimum pH values of enzyme activities varied. The culture fluids of several other fungi also catalysed development of fluorescence in solutions containing HVA. p-Hydroxyphenylacetic acid was a poor substrate for all laccases in vivo except that produced by Perennipora tephropora.

Topics: Benzothiazoles; Fermentation; Fungi; Homovanillic Acid; Horseradish Peroxidase; Hydrogen Peroxide; Hydrogen-Ion Concentration; Indicators and Reagents; Laccase; Oxidoreductases; Phenylacetates; Spectrometry, Fluorescence; Sulfonic Acids