SCREENING OF THE EUKARYOTIC ORGANISMS ABILITY TO DECOLORIZE THE AZO DYE CONGO RED IN SOLID MEDIA

GONZALEZ PAISIO Z; LAMPA AMN; OLARIAGA V; KURINA SANZ M; MAGALLANES-NOGUERA C; BONILLA JO

Congreso; Congreso Anual de la Sociedad de Biología de Cuyo; 2023

SBC

Textile industry generates wastewater with complex composition, since it contains acids, alkalis, hydrogen peroxide, starch, surfactants and heavy metals, in addition to a large quantity and variety of dyes. In this industry, the most recalcitrant elements are the azo dyes, which are widely used due to their photolytic stability and their resistance to microbial degradation. These properties, which make dyes with high commercial value, are precisely the same ones that make them difficult to be degradable compounds. In this sense, the search for organisms that are capable of removing and/or degrading xenobiotics, such as azo dyes, is imperative to position them as biological systems with the potential to develop efficient environmental remediation strategies that minimize the impact of our activities on the environment. In this work, we aimed to test the capacity of different eukaryotic organisms, including in vitro plant cultures and white rot fungi, to decolorize in solid medium the azo dye Congo Red (C32H22N6Na2O6S2, 696.66 g mol-1). The qualitative decolorization test was performed by facing the organisms to the azo dye at 250, 500 and 1000 µg mL-1. Medicago sativa, Tessaria absinthioides and Daucus carota undifferentiated plant cells faced Congo Red in solid Murashige & Skoog medium supplemented with vitamins, pH 5.8, during 21 days at 22 ± 2 °C. On the other hand, Trametes villosa, Pleurotus djamor and Trametes sanguinea where exposed to Congo Red in potato dextrose agar medium at 30 °C during 16 days. M. sativa was unable to decolorize Congo Red from solid medium. On the contrary, D. carota and T. absinthioides were able to decolorize in all the tested concentrations. In these organisms, a strong pigmentation of the biomass was observed. Regarding the decolorization capacity of white rot fungi species, T. sanguinea showed decolorization only at 250 µg mL-1, while T. villosa was able to decolorize up to 500 µg mL-1, and P. djamor showed decolorization in all the tested concentrations. Pigmentation of mycelia was observed in T. villosa and T. sanguinea, but not in P. djamor. These preliminary results position some of the evaluated eukaryotic organisms as candidates for further studies on the removal/degradation of azo dyes, in order to confront them with real wastewater from the textile industry later.