High dye removal capacity of Peniophora laxitexta immobilized in a combined support based on polyurethane foam and lignocellulosic substrates

MAJUL L.M.; WIRTH S.A.; L.N. LEVIN

ENVIRONMENTAL TECHNOLOGY

TAYLOR & FRANCIS LTD

Lugar: Londres; Año: 2022 vol. 43 p. 684 - 695

0959-3330

Dye removal from effluents is a major problem for most textile industries. At present, 3 wastewater treatments are currently based on physico-chemical methods which are 4 expensive, energy inefficient and of limited versatility. The aim of this work was to find a low- 5 cost and efficient method for dye removal. To do this, we designed a combined system 6 based on the immobilization of the ligninolytic white-rot fungus Peniophora laxitexta (BAFC 7 4687) on mixed supports consisting of two polyurethane foam discs and a middle layer of 8 diverse lignocellulosic substrates: soybean hulls, wheat straw or cellulose spent casings. As 9 a corticioid fungus, P. laxitexta was able to completely colonize the supports developing a 10 compact and tight structure that maintained the integrity of the system after several dye 11 removal cycles. The immobilized fungus removed between 30 to 50% of the azoic dye 12 Xylidine and more than 50% of the anthraquinonic dye RBBR in three successive cycles, 13 and near 90% of the triphenylmethane Malachite Green in 10 repeated cycles without any 14 loss of efficiency. Our analysis showed that the removal of the dyes was due to the 15 combined effect of adsorption to the supports and enzymatic decolorization by soluble 16 laccases and enzymes associated with the mycelium. Additionally, we showed that the 17 presence of Malachite Green induced the expression of a new laccase isoform with high 18 decolorization capacity. Based on these results, we propose that this inoculated laminar 19 biocarrier could be effectively used for dye removal in textile wastewater.