Rapid Diazonium Blue B Test to Detect Basidiomycetous Yeasts

Abstract

More than 100 known eucaryotic microorganisms were examined for capacity to form red to violet pigments with diazonium blue B after alkaline hydrolysis and an ethanol wash. All 50 basidiomycetes gave rapid and unequivocal positive reactions when 1-to 6-day-old cultures were tested, whereas all ascomycetes and algae gave negative reactions. Extracellular enzymes generally considered to be typical of basidiomycetous yeasts were detected in several ascomycetous taxa.