P5: Discoloration of indigo carmine using crude peroxidase extracts from chayote fruit and peel

Traditional textile industry consumes about 100 liters of water to process 1 Kg of material, it has been estimated that 10 % of the dye does not bind to the fibers. Then textile wastewater creates environmental problems due the contamination with dyes. These compounds are not degraded or removed with physical or chemical processes, for this reason dyes remain unchanged in wastewater treatment plants and are discharged to rivers. In other hand there are some advanced treatment systems to discolor textile dyes but they are expensive. The aim of this study was to test crude peroxidase extracts from fruit and peel of chayote to discolor indigo carmine dye. Fruit and peel of chayote were blended with buffer at different pH 3, 4, 5, 6, 7 and 8, centrifuged and filtrated; extracts were mixture with indigo at 100 ppm at room temperature and magnetically stirrer during 24 hours. % of discoloration was calculated by measuring change in absorbance at 610 nm. Experiments were repeated at the best pH value and using indigo at 50, 100, 200, 500 and 1000 ppm. For both peel and fruit of chayote the best pH was 6; peel discolored dye solutions but in less than 40 %; whereas using fruit discoloration was completely in solutions at 50, 100 and 200 ppm and 60 % in solution at 500 ppm. Crude peroxidase extracts could discolor indigo dye; therefore this is a simple and cheap way to treat some textile dye solutions efficiently.