Efeito da concentração do corante vermelho congo na degradação/absorção pelo fungo Lentinus crinitus CCIbt 2611.

Abstract

The contamination of water has become a major concern of the XXI Century and the textile industry, a sector that requires a large water demand, is responsible for the generation of large volumes of wastewater containing dyes, mostly, toxic, mutagenic, carcinogens and many other chemicals that harm the environment. Thus, this study aimed to evaluate the potential for discoloration of the textile dye Congo red by the fungus L. crinitus CCIBt 2611. This study evaluated the discoloration of different dye concentrations in solid medium and in stationary liquid medium and stirred. The largest halos enzymatic degradation index on solid medium were up to 2.86 at a time of 120 hours incubation for a concentration of 20 mg.L-1 of dye. In liquid medium, it was up to 89.35% maximum percentages for the discoloration concentration of 30 mg.L-1 of dye with 24 hours of cultivation, the activity was not detected laccase enzyme for the duration of this experiment. Growth speed on solid medium L. crinitus study showed that the micro-organism is tolerant of low concentrations of Congo red, but the increase of the concentration becomes toxic with increasing time of exposure to dye. The fungus halos showed microbial growth by 1.44 cm at the concentration of 20 mg.L-1 and 1.08 cm for up to concentration of 80 mg.L-1, showing tolerance to high concentrations of the dye. For liquid media, both in culture and in stationary cultivation under agitation, the microorganism was able to maintain its growth at concentrations of 20 and 25 mg mg.L-1 of dye, however the concentrations for 30 and 40 mg.L-1 resulted in decreased growth. Given the above, it can be said that the fungus L. crinitus CCIBt 2611 shown microorganism a potential for degradation / adsorption of azo dyes such as Congo Red, allowing the use of a method applied in discoloration high concentrations of the dye, using less expensive means of treating wastewater. However, it is necessary that further studies be made to better understand the mechanisms involved in the degradation of azo dyes by L. crinitus.