Decolourization and detoxification of textile dyes by Lentinus arcularius in immersion bioreactor scale

Abstract

The present study was aimed to optimization of substrate and culture type for lignin-modifying enzymes, decolourization of six synthetic dyes and mycoremediation of artificial textile effluent in bioreactor scale by Lentinus arcularius as a first report. The specific enzyme activity and decolourization capacities of lignin-modifying enzymes were determined using spectrophotometric methods. The highest manganese peroxidase and laccase activities were achieved using solid-state fermentation with tea wastes which was 3.82- and 3.69-fold higher than the control. The representative of azo, anthraquinone and triarylmethane dye groups could be completely decolourized in 1.5–3.0 h by Lentinus arcularius. The lignin-modifying enzymes immobilized in calcium alginate beads with high immobilization yield were used for mycoremediation of artificial textile effluent in flask and reactor scales. It was achieved to almost 90% decolourization for all dyes in each of successive two cycles in flask scale. After four cycles, enzyme activity retained 63% still. Both of manganese peroxidase and laccase enzymes of Lentinus arcularius have a role in decolourization of the textile dyes. In immersion reactor scale, a linear relation was determined between decolourization and detoxification of the tested dyes; 88% decolourization of the effluent was led to 80% decrease in mortality of brine shrimp nauplii.