Optimization of methylene blue degradation by Aspergillus terreus YESM 3 using response surface methodology

Abstract

Synthetic dyes released from many industries cause pollution problems in aquatic environments affecting public health. The present study aimed to explore the potentiality of Aspergillus terreus YESM 3 (accession number LM653117) for colour removal of three different dyes: methylene blue (MB), malachite green (MG) and safranin (S). Results showed that the tolerance index of the studied fungus against tested dyes decreased in the order: methylene blue, safranin and malachite green. Removal of methylene blue colour was improved by using Box–Behnken design. Optimum condition for methylene blue biodegradation in Czapek Dox broth was achieved at pH 6, of 31.41 mg/L dye concentration and an inoculum of 5.7778 × 104 (conidia/mL) with biodegradation of 89.41%. Thus, a novel and eco-friendly system for the biodegradation of dyes using Box–Behnken design has been efficiently developed. Accordingly, A. terreus YESM 3 can be professionally used for bioremediation of methylene blue dye in wastewater and removal of environmental pollution.