Mycoremediation of Congo red dye by filamentous fungi

Abstract

Azo, anthroquinone and triphenylmethane dyes are the major classes of synthetic colourants, which are difficult to degrade and have received considerable attention. Congo red, a diazo dye, is considered as a xenobiotic compound, and is recalcitrant to biodegradative processes. Nevertheless, during the last few years it has been demonstrated that several fungi, under certain environmental conditions, are able to transfer azo dyes to non toxic products using laccases. The aim of this work was to study the factors influencing mycoremediation of Congo red. Several basidiomycetes and deuteromycetes species were tested for the decolourisation of Congo red (0.05 g/l) in a semi synthetic broth at static and shaking conditions. Poor decolourisation was observed when the dye acted as the sole source of nitrogen, whereas semi synthetic broth supplemented with fertilizer resulted in better decolourisation. Decolourisation of Congo red was checked in the presence of salts of heavy metals such as mercuric chloride, lead acetate and zinc sulphate.Decolourisation parameters such as temperature, pH, and rpm were optimized and the decolourisation obtained at optimized conditions varied between 29.25-97.28% at static condition and 82.1-100% at shaking condition. Sodium dodecyl sulphate polyacrylamide gel electrophoretic analysis revealed bands with molecular weights ranging between 66.5 to 71 kDa, a characteristic of the fungal laccases. High efficiency decolourisation of Congo red makes these fungal forms a promising choice in biological treatment of waste water containing Congo red.

Trichoderma Biomass as an Alternative for Removal of Congo Red and Malachite Green Industrial Dyes

“…(97%); however, the concentration of CR used in the present study (50 mg L −1 ) is higher than those reported for T. versicolor or Thelephora with 31 mg L −1 and 35 mg L −1 , respectively [57] (Table 1). In contrast, when the CR concentration was 50 mg L −1 , the removal observed for T. versicolor, 82%, for Aspergillus niger, 9%, for A. oryzae, 52%, for Penicillium chrysogenum, 10%, for Cladosporium rubrum, 10%, and Pleurotus ostreatus, 12% [58,59], were lower than that obtained in the present study. The removal percentages of CR by the dead mycelium of T. virens (94%) and T. viride (95%) are higher than those described for the mycelium of T. versicolor under three conditions: (a) autoclaved (90%), (b) acidic (49%), and (c) alkaline (42%) [58] (Table 1).…”

Bio-Removal of Methylene Blue from Aqueous Solution by Galactomyces geotrichum KL20A

“…As shown, the pH is a critical factor for MB biodegradation. It has been suggested that microbial cells are significantly affected by the pH of their immediate environment because they apparently have no mechanism for adjusting their internal pH [34]. The pH of dyes discharged in wastewater varies greatly as a result of their pH dependent nature.…”

Microbial Degradation of Azo Dyes: Approaches and Prospects for a Hazard-Free Conversion by Microorganisms

“…As opposed to adsorption, the degradation of azo dyes has been of significant interest as ideally, the dyes can be completely degraded by the microbial enzymes. Microorganisms capable of decolorizing and degrading dyes include filamentous fungi [87,88], yeasts [89,90], algae [91,92], and bacteria [93][94][95].…”