Removal of textile dye reactive black 5 by the cold-adapted, alkali- and halotolerant fungus Aspergillus flavipes MA-25 under non-sterile conditions

Abstract

The aim of the present study was to investigate the potential of isolated fungus Aspergillus flavipes MA-25 to decolorize the textile dye reactive black 5. The fungus was found to be capable of removing the dye from the culture in a wide pH range (not only acidic but also neutral and alkaline pHs) at high salt concentrations (0–50 g/L) and low temperatures (5–35°C) under non-sterile conditions. It was also observed that the fungus could tolerate the dye at high initial concentrations up to 1 g/L. Especially, no significant inhibitory effect on dye removal and fungal growth was seen at the initial dye concentrations of ≤0.4 g/L. At initial dye concentration of 0.2 g/L, complete removal of dye was achieved with 4.71 g/L biomass production in 80 h. The bioadsorption was the principle mechanism involved in dye removal by the fungus. Therefore, it was assumed that the fungus had a great potential for the treatment of dye-bearing textile effluents which are alkaline, cold, and saline.

Keywords:

• Aspergillus flavipes MA-25
• Textile dye
• Reactive black 5
• Dye removal
• Cold-adapted