Evaluation of novel fungal cellulase preparations for ability to hydrolyze softwood substrates – evidence for the role of accessory enzymes

An optimized microplate assay system for quantitative evaluation of plant cell wall–degrading enzyme activity of fungal culture extracts

“…In contrast to pure cellulose, however, the plant cell wall is a heterogeneous matrix of polysaccharides with diverse composition and linkages, as well as aromatic compounds found in lignin, such that hydrolysis of plant biomass is much more complex than for pure cellulose (Berlin et al, 2005(Berlin et al, , 2007Rose, 2003;Schmer et al, 2008). Commercial enzyme preparations comprising various T. reesei enzymes such as endoglucanases, cellobiohydrolases and b-glucosidases are often limited in their activity on lignocellulosic substrates, and activities determined on filter paper, Avicel, and CMC do not necessarily correlate with activities on biomass (Berlin et al, 2005;Chundawat et al, 2008).…”

“…Commercial enzyme preparations comprising various T. reesei enzymes such as endoglucanases, cellobiohydrolases and b-glucosidases are often limited in their activity on lignocellulosic substrates, and activities determined on filter paper, Avicel, and CMC do not necessarily correlate with activities on biomass (Berlin et al, 2005;Chundawat et al, 2008). Complete hydrolysis requires relatively large quantities of the enzyme product and often must incorporate additional enzymes with different catalytic behaviors in order to better degrade lignocellulosic biomass (Rosgaard et al, 2006).…”

“…The conventional International Union for Pure and Applied Chemistry (IUPAC) filter paper assay (FPA) method for measuring hydrolytic activity has been automated by Decker et al (2003) to reduce operator error and adapted to use small reaction volumes by Xiao et al (2004). Berlin et al (2005) developed a high through-put screening assay utilizing lignocellulosic substrates. A high-throughput methodology for measuring the digestibility of lignocellulosic biomass has been developed by Chundawat et al (2008) using crystalline cellulose (Avicel) and ammonia fiber expansion (AFEX) pretreated-corn stover as substrates and a bio-enzymatic assay to determine fermentable sugars.…”

Obtaining New Cultures Of Microorganisms That Produces Cellulases And Xylanases From The Sugarcane Bagasse

“…Partially delignified cellulignin (PDC) showed to be a poor inducer of L04 cellulases with delayed enzymatic production, contrary to expectations where delignification can improve enzyme production, since the large amount of lignin in SCB could irreversibly adsorb the enzymes produced during fungal cultivation. This would also be expected during hydrolysis where the absence of lignin probably reduces the adsorption of cellulolytic enzymes onto the lignin fraction of biomass (Berlin et al 2005). This behavior was also reported for a T. harzianum strain isolated from the Amazon rainforest grown on pretreated sugarcane bagasse (Delabona et al 2012).…”

Expression of Glycosyl Hydrolases in Lignocellulosic Feedstock: An Alternative for Affordable Cellulosic Ethanol Production

“…In addition, xylanases and other accessory enzymes such as acetyl xylan esterase and ferulic esterase hydrolyze xylan, which in many species is the most abundant hemicellulose component [14]. These accessory enzymes significantly enhance the performance of cellulases and improve enzymatic hydrolysis [15][16][17]. Currently, cell wall hydrolytic enzymes are produced for commercial purposes in microorganisms, including bacteria such as Bacillus subtilis [18] and fungal systems such as Trichoderma reesei [19].…”