Biodegradation of the diazo dye Reactive Black 5 by a wild isolate of Candida oleophila

Abstract

This work looks for a better understanding of the biodegradation of xenobiotic azo dyes mediated by yeasts. During a screening program of phenolic acid assimilating capacities it was found that a non-conventional ascomycetous yeast isolate, identified as Candida oleophila, efficiently decolorizes agar plates supplemented with the commercial textile diazo dye Reactive Black 5. Aerobic batch cultures of C. oleophila could completely decolorize up to 200 mg dye l −1 , an ability not yet reported for this yeast species. Moreover, this performance has been achieved in just 24 h of incubation at 26 • C in the presence of as little as 5 g glucose l −1 and without visible signs of dye adsorption to yeast cells. It was found that decolorization occurs during the exponential growth phase and neither laccase nor manganese-dependent peroxidase activities were detected in the culture medium. As far as the decolorization mechanism is concerned, our results indirectly suggest the involvement of an azoreductase-like activity in azo bonds cleavage.

Degradation and detoxification of three textile Azo dyes by mixed fungal cultures from semi-arid region of Brazilian Northeast

“…However, more studies are needed on the ability of fungi regarding decolorization and detoxification of dyes used by the textile industry. Many works relate the potential for decolorization of fungi from already impacted areas (Yang et al, 2005;Lucas et al, 2006). However, results obtained with fungi from non-impacted areas have also shown to be promising (Junghanns et al, 2007;Pajot et al, 2007).…”

Aerobic decolorization of azo dye orange g by a new yeast isolate Candida cylindracea SJL6

“…Although there are reports of yeasts that can use a dye as a sole source of carbon and/or nitrogen for dye degradation, this process is highly associated with the cell growth and primary metabolism (LUCAS et al, 2006;YANG et al, 2008;PAJOT et al, 2011;MORTARELL et al, 2012). Therefore, yeasts do not generally grow without glucose or any other readily metabolizable carbon source (SOLÍS et al, 2012).…”

“…The same has been described for biodegradation of different dyes by yeasts LIU et al, 2011;TAN et al, 2014). Enzymes such as manganese peroxidase (MnP), lignin peroxidase (LiP), NADHdichlorophenol indophenol reductase, and azoreductases are some of the major enzymes involved in dye biodegradation by yeasts (YANG et al, 2005;LUCAS et al, 2006;JADHAV et al, 2008;WAGHMODE et al, 2011).…”

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“…However, more studies are needed on the ability of fungi regarding decolorization and detoxification of dyes used by the textile industry. Many works relate the potential for decolorization of fungi from already affected areas 5,6 . However, results obtained with fungi from unaffected areas have also shown to be promising 7,8 .…”