Efficacy of Aspergillus fumigatus MCC 1175 for Bioremediation of Tannery Wastewater

Abstract

Tannery effluent is characterized by high concentrations of chromium, nitrogen, sulfur compounds, and organic matter such as tannins. Chromium and tannins are considered an important source of contamination due to their toxic nature and large volume of liquid discharged and solid sludge produced. In the present study, bioremediation of chromium and tannic acid is studied in a batch culture system using response surface methodology. Scanning electron microscopy (SEM) coupled with energy‐dispersive X‐ray (EDX) and Fourier‐transform infrared spectroscopy (FTIR) are used to investigate adsorption phenomena. A chromium and tannic acid resistance fungal strain is isolated from tannery effluent, and identified as Aspergillus fumigatus MCC 1175 based on its 18S rDNA gene sequence. The minimum inhibitory condition (MIC) of the isolate against chromium and tannic acid was found to be 0.2 and 10 mg mL−1, respectively. The maximum Cr(VI) removal efficiency of 65.1% is found at optimum condition of pH 7, 96 h incubation period, 2.75% inoculum, and 0.1 mg mL−1 chromium. The maximum degradation of tannic acid (63.0%) occurs at pH 5, 27.5 mg mL−1 tannic acid, 100 rpm agitation speed, and an incubation period of 96 h. FTIR analysis of A. fumigatus MCC 1175 revealed the presence of carboxyl and phosphate groups as possible binding sites.