Potencial biotecnológico de linhagens de fungos filamentosos isolados da mata atlântica na biodegradação de corantes têxteis e avaliação dos possíveis efeitos de toxicidade

Abstract

When textile industries discharge their effluents into water bodies, they require efficient treatments to ensure that the toxic compounds from the dyes used do not become even more toxic during the treatment process and do not pose a risk to the environment or public health. In this scenario, this work studies the biological treatment of effluents in the presence of textile dyes using the filamentous fungi Penicillium (strains I05-01 and I13-07), Trichoderma (strain IS10-08), and Aspergillus (strain I05-06). The azo dyes Direct Yellow 27, Reactive Black 5, and Methyl Orange were used. The evaluation of plate discoloration in potato medium for seven days at 28°C at concentrations of 50 and 100 ppm indicated that the discoloration of Direct Yellow 27 and Reactive Black 5 dyes was most promising when using lines I13-07 and I0-06. Dye discoloration tests were performed in a submerged system, both with pure lines and in consortia, in 500 mL Erlenmeyer flasks containing 125 mL of potato dextrose broth, pH 5.5, supplemented with textile dyes. The toxic potential of the treated media was analyzed in tests with Lactuca sativa and Phaseolus vulgaris seeds, and with the microcrustacean Daphnia similis. In parallel, the enzymatic activity of lipase, laccase, and manganese peroxidase enzymes was evaluated under different conditions. The I13-07 line stood out for presenting high potential for the biodiscoloration of the Reactive Black 5 and Direct Yellow 27 dyes, low toxic potential for the seeds and microcrustaceans used in the treatment of the Direct Yellow 27 dye, and greater enzymatic activity in the production of Manganese Peroxidase, showing itself to be a line with interesting biotechnological potential for the development of future studies.