 "Fusarium oxysporum" efficiently decolourizes the first-generation Glycoazodye 4-{N,N-Bis[2-(D-galactopyranos-6-yloxy)ethyl]-amino}azobenzene.Various other Ascomycota fungi show a similar potential to decolourise Glycoazodyes, but to a lesser extent.Detoxification has been measured, using the "Daphnia magna" acute toxicity test, showing a 92% dye detoxification after 6 days.