Valorisation of textile waste by fungal solid state fermentation: An example of circular waste-based biorefinery

This study investigated the feasibility of using textile waste as feedstock for cellulase production through solid state fermentation. Aspergillus niger CKB was selected with the highest cellulase activity (0.43 +/- 0.01 FPU g(-1)) after 7 days of cultivation on pure cotton. Material modification techniques including autoclaving, alkali pretreatment and milling were applied on six types of textiles with various cotton/polyester blending ratios. The results indicated that using autoclaved textile blending cotton/polyester of 80/20 led to the highest cellulase activity (1.18 +/- 0.05 FPU g(-1)) with CMCase, beta-glucosidase and avicelase activities of 12.19 +/- 0.56 U g(-1), 1731 +/- 4.98 U g(-1) and 2.58 +/- 0.07 U g(-1), respectively. The fungal cellulase was then extracted and applied to textile waste hydrolysis, in which a sugar recovery yield of 70.2% was obtained. The present study demonstrates a novel circular textile waste-based biorefinery strategy with recovery of glucose and polyester as value-added products.