Profiling the Effects of pH and Temperature on Azo Dye-Decolourisation by <i>Aspergillus quadrilineatus</i> Strain BUK_BCH_BTE1 Isolated from Textile Effluents

Abstract

Wastewater from textile industries contains azo dye residues that negatively affect most environmental systems. The biological treatment of these wastes is one of the best option due to safety and cost concerns. This research was therefore aimed to isolate and identify fungus capable of decolorizing and utilizing azo dye (dimethyl yellow) as a sole carbon source using one-factor-at-a-time (OFAT). Pour plating method was used to isolate the fungus on mineral salt media (MSM) following serial dilution. The isolate was then morphologically and molecularly identified as Aspergillus quadrilineatus strain BUK_BCH_BTE1 with the accession number OK178927 based on ITS1 and ITS2 rRNA gene sequence and molecular phylogenetic analysis. Characterization was conducted by studying the effect of temperature and pH, in MSM media containing dimethyl yellow as sole carbon sources. The growth of this fungal isolate with dimethyl yellow as substrate was optimal at, temperature of 30 °C, and pH of 5.0. At these optimum conditions the isolate was able to decolourised up to 74.3% of dimethyl yellow dye. The isolate could be a suitable candidate in bioremediation of coloured effluents particularly containing these compounds.