Culture media optimization for Reactive Black 5 decolourization by trichosporon porosum MM 4029

VIEJOBUENO, J.; PAJOT, HIPOLITO FERNANDO; LUCÍA I.C. DE FIGUEROA

Wisconsin

Congreso; XIII International Congess on Yeasts; 2012

International Commission on Yeast

Textile dyes are engineeredto be resistant to environmental conditions. During the last years thetreatment of textile dye effluents has been the focus of significant researchbecause of the potentially low cost of the process. Mechanisms of biologicaltextile dyes decolourization greatly depend on the dye chemical structure, theemployed microorganisms and media culture composition. In this study, decolourizationof the diazo dye Reactive Black 5 was carried out by the native yeast Trichosporon porosum 4029. The effect ofpeptone, CaCl2, KH2PO4, MgSO4, glucose,yeast extract and (NH4)2SO4 were initially studiedin a seven factor Plackett?Burman design. Only glucose, yeast extract and (NH4)2SO4showed a significant effect on dye decolourization; whereas peptone, CaCl2,KH2PO4 and MgSO4 could be safely excluded fromdecolourization medium. Subsequently, a three factor full factorial design wasemployed in order to study the effect and interactions between glucose, yeastextract and (NH4)2SO4 concentration on dyedecolourization. In optimized medium, glucose and (NH4)2SO4final concentrations were decreased to 10 g/l and 1.25 g/l, whereas yeastextract final concentration was reduced to a 1 g/l. Those values represent a 60% reduction for the initial concentration of yeast extract and 50 % for theother two components. Under those optimized conditions, Trichosporon porosum was able to decolourize almost completely 200mg/l of Reactive Black 5 within 24 h. Results has allowed the formulation of anew decolourization medium, simpler and greatly reduced in costs, for itsfuture use in bioremediation processes.