PEER-REVIEWED ARTICLE bioresources.com Pinheiro et al. (2021). “Fungal enzymatic bleaching,” BioResources 16(4), 7509-7529. 7509 Utilizing a Novel Fungal Enzymatic Cocktail as an Eco- Friendly Alternative for Cellulose Pulp Biobleaching Vanessa Elisa Pinheiro, a Jorge A. Ferreira, b Jorge Henrique de Almeida Betini, c Eliana Setsuko Kamimura, d and Maria de Lourdes Teixeira de Moraes Polizeli a,c * Enzyme cocktails can alter the lignin and hemicellulose content in wood cell walls, improving the bleaching process during pulp production and offsetting the need for toxic chemicals. In this study, brown pulp was biobleached with a mixture of crude fungal extracts rich in xylanase and laccase, respectively produced from Aspergillus tamarii Kita and Trametes versicolor on waste materials. The optimal conditions for biobleaching were a mixture of xylanase and laccase crude extracts (1 to 2 v/v), at a temperature of 36 °C and a pH of 5.5. The treated brown cellulose pulp showed a reduction in the Kappa number by 1.83 points, representing an efficiency of 20.3%. In addition, the brightness increased by 4.65 points in comparison to the control. Hence, studies involving the application of the standardized cocktail during the hydrolysis of lignocellulosic residues, e.g., barley residue and sugarcane bagasse, led to the formation of 85 g/L and 25 g/L of reducing sugars, respectively. Moreover, the standardized cocktail caused greater deinking of the recycled paper pulp. Keywords: Enzymes; Aspergillus tamarii Kita; Trametes versicolor; Cellulose pulp; Biobleaching; Central composite design Contact information: a: Ribeirão Preto Medical School - São Paulo University. Bandeirantes Av., 3.900, Ribeirão Preto14040-900 Brazil; b: Swedish Centre for Resource Recovery, University of Borås, Borås 501 90 Sweden; c: Faculty of Philosophy, Sciences and Letters at Ribeirão Preto - São Paulo University. Bandeirantes Av., 3.900, Ribeirão 14040-901 Preto, SP, Brazil; d: Faculty of Animal Science and Food Engineering - São Paulo University. Duque de Caxias Av., 225, Pirassununga 13635-900 SP – Brazil; * Corresponding author: polizeli@ffclrp.usp.br INTRODUCTION The pulp and paper industry has a challenging position concerning the environment. While this industry is based on the usage of renewable and photosynthetic resources, it still discards a large amount of effluents (over 70 m 3 of wastewater is generated for each ton of processed paper, depending on the nature of the raw material) (Hubbe et al. 2016). Among the major cellulose-producing countries, Brazil is the largest eucalyptus pulp producer in the world. The country stands out worldwide in terms of producing and suppling markets with substantial pulp volumes (CNI 2014). Due to the versatility in dealing with different raw materials, the kraft (sulfate) process is the dominant chemical pulping method. The recalcitrant lignins, cellulose, phenols, fatty acids, tannins, and resins from materials are washed off as black liquor during the heating step (under high alkaline pH and temperature conditions). The pulp produced through this process is strong but darkly colored, which is not desirable for many products. Consequently, multistep bleaching is required to achieve higher pulp brightness (Kumar et al. 2011; Sharma et al. 2020). Industries use various chemical reagents, oxidants, alkalis, and acids to bleach cellulose pulp, e.g., chlorine dioxide (ClO2), oxygen