Exoglucohydrolases are responsible for removal of glucose units from the non-reducing ends of cyclodextrins. Finally, β-glucosidases hydrolyze cellobiose into glucose and also remove glucose units from non-reducing check details ends of small cyclodextrins. Hydrolysis of the hemicellulose fraction requires a more complex group of enzymes, referred to as hemicellulases. Complete enzymatic hydrolysis of xylan, the major polymer founded in hemicelluloses, requires endo-β-1,4-xylanase (EC 3.2.1.8), which acts randomly on the internal bond

of xylan to release xylo-oligosaccharides, β-xylosidase (EC 3.2.1.37) which hydrolyzes the non-reducing ends of xylose chains to release xylose, and several accessory enzymes including α-l-arabinofuranosidase (EC 3.2.1.55), α-glucuronidase selleck products (EC 3.2.1.139), α-galactosidase (EC 3.2.1.22), acetylxylan esterase (EC 3.1.1.72) and ferulic acid esterase (EC 3.1.1.73) [10] and [11]. The concept of accessory enzymes has evolved over time since most are considered essential in enzymatic cocktails to increase sugar yields during biomass saccharification [12]. Moreover, studies have shown that supplementation of cellulase mixtures with hemicellulases can improve the rate and yield of glucan conversion since the removal of hemicellulose exposes the cellulose fibrils and increases substrate accessibility

[13]. Synergism between the enzymes is a widely observed phenomena in biomass hydrolysis and it depends on several factors including the nature of the substrate and the source of enzymes [13]. Design of glycoside hydrolase mixtures with small amounts of synergistic proteins to release sugars from biomass presents to be an effective strategy. Recently, combined utilization learn more of synergistic proteins lacking glycoside hydrolase activity (non-GH), such as carbohydrate-binding modules, plant expansins,

expansin-like proteins, and Auxiliary Activity family 9 (formerly GH61) proteins, have been suggested as an effective option to facilitate the release of sugars from lignocellulosic biomass since they act by inducing structural modifications in cellulose without causing significant hydrolysis [14••]. Microorganisms play an essential role on production of enzymes for biomass saccharification. Therefore, different strategies are used for the prospection of novel and/or more efficient enzymes that hydrolyze lignocellulose. One example consists of bioprospecting of microorganisms in specific environmental niches with posterior investigation of their ability to hydrolyze crude substrates, followed by screening of the best candidates that possess interesting enzymes. Another strategy is the metagenomic tool which is extensively utilized for the genetic composition analysis of microorganism mixtures using probes or group-specific primers for seeking new (hemi)cellulases [15].