Role of brown-rot fungi in the bioremoval of azo dyes under different conditions

Abstract

The present study is vital to the understanding of bioremediation of structurally different azo dyes by some unusual Brown-rot fungi. Bioremoval of each dye (20 mg l-1) was tested in two different culture media under static and shaking conditions by taking inocula from different fungi. Fungal strains showed varying dyes removal abilities, though considerable high in case of Acid Red (AR) 151(di-azo) as compared to Orange (Or) II (mono-azo). With an exception of Aspergillus tereus SA3, all the fungal isolates showed higher removal of dyes in SDB. Under static condition, the maximum decolorizing fungal strains were; Aspergillus flavus SA2 (67%) and Alternaria spp. SA4 (57%) in AR 151, while Penicillium spp. (34 and 33 %) in Orange II, in SDB and STE, respectively. Bioremoval of dyes was considerably increased when experiments were shifted from static to shaking mode. It was specifically increased (%) in; AR 151 (255) with Penicillium spp., Or II with A. flavus SA2 (112) and Alternaria spp. (111). The primary mechanism of dyes removal proved to be fungal biosorption. However, reduction of dyes (onto fungal) with formation of their products (α. naphthol, sulphalinic acid and aniline) furthermore revealed that dyes (specifically azo) were actually biodegraded.

Fungal decolouration and degradation of azo dyes: A review

“…and Penicillium sp. (Ali et al, 2009(Ali et al, ,2010. Decolouration can be increased if the pH is kept constant during the process at a value that is favourable for fungal growth (Arroyo-Figueroa et al, 2011).…”

Optimization of Culture Condition for Enhanced Decolorization of Direct blue Dye by Aspergillus flavus and Penicillium canescens

“…El-Sayeh (2010) also found that the maximal decolorization of Direct Violet dye by Aspergillus fumagatus obtained at the fourth day but decreased after that as well as the level of enzyme production. Ali et al (2010) Also found that decolorization rate by brown-rot fungi for azo dyes was generally high at 96 h. Moreover, it kept on declining with passing time in agitated fungal cultures. Machado et al (2006) also reported this decreasing trend in decolorization with time, and explained that this phenomenon might be due to accumulation of dyes products that might have hindered growth and metabolizing potential of fungi.…”

Filamentous Fungi and Chemistry: Old Friends, New Allies

“…129 Os corantes também são contaminantes orgânicos amplamente presentes no ambiente devido ao crescimento das indústrias têxteis, que consomem uma matriz extensa e diversificada de produtos químicos na forma de corantes. Em diversos casos, o mecanismo principal de remoção de corantes azo ocorre por biosorção, como relatado para os fungos A. flavus e Alternaria spp.. 130 A biorremediação do corante verde de malaquita pelos fungos A. niger e Phanerochaete chrysosporium chegou a 72,77% e 83,25%, respectivamente. 131 Ao se utilizar o fungo Myrothecium roridum, a biorremediação foi superior a 90%, graças ao mecanismo de oxidação enzimática por lacases produzidas pelo fungo.…”