Characteristics of a New Fungus Isolated for Dye Decolorization

Abstract

As a dye-decolorizing microorganism, a fungus, identified as Geotrichum candidum Dec 1, was isolated from the soil. Re-identification of this fungus revealed it to be Thanatephorus cucumeris Dec 1 abbreviated as Dec 1. A crude extracellular enzyme solution was prepared from the culture of Dec 1, and the enzyme solution showed a broad decolorization spectrum of dyes in the presence of H2O2 , indicating the existence of multiple enzymes, including peroxidases. Dec 1 decolorized approximately 12 g/1 of the dye, Reactive Blue 5 (RB5), without a decline in the decolorizing activity at the inhibitory concentration for most of the microorganisms, indicating the resistant property of Dec 1 to a high concentration of the dye RB5. Dec 1 expressed decolorizing activity in the presence of carbon sources and oxygen.

Keywords: Geotrichum candidum Dec 1, Thanatephorus cucumeris Dec 1, Peroxidase, Reactive Blue 5, Veratryl Alcohol, Azo dye, Anthraquinone dye.