Enzymatic breakdown of lignocellulosic biomass: the role of glycosyl hydrolases and lytic polysaccharide monooxygenases

Abstract

Lignocellulose constitutes a major component of discarded wastes from various industries viz. agriculture, forestry and municipal waste treatment. The potential use of lignocellulose from such types of biomass can be maximized by enzymatic degradation using glycoside hydrolases (GHs) and oxidative enzymes to produce renewable fuels. Nonetheless, besides the slow rate of degradation and low yields, lignocellulose is also physicochemically recalcitrant and costly to process, further limiting its mass utilization. Therefore, bioprospecting for microorganisms producing efficient lytic polysaccharide monooxygenases (LPMOs) to overcome these drawbacks may prove beneficial. The use of GHs and LPMOs can potentially help to circumvent some limitations in the conversion of lignocellulosic biomass into fermentable sugars. LPMOs are classified as family GH61 or family 33 carbohydrate-binding module (CBM33), whose unusual surface-exposed active site is bound to a copper (II) ion. To date, there are more than 20 known genes encoding cellulose-active LPMOs in bacteria and fungi, with diverse biological activities. Only by thorough comprehension of the diversity, enzymology and role of primary GHs, i.e. celullases and their oxidative machinery can the degradation of lignocellulosic biomass be improved. This review provides insight into the diversity, structure and mechanisms, structural and functional aspects of the oxidative breakdown of cellulose by LPMOs of the cellulose-active GH family.

On the Renewable Polymers from Agro-industrial Biomass: A Mini Review

“…The reason being that cellulose is structurally entrapped by the cell-wall components. This renders limited access of biodegrading enzymes to breakdown of the complex network into shorter repeating units of monosaccharides [15,28]. Conversely, the chemical route, on the other hand, utilizes different types of acids to digest cellulose.…”

“…Biomass also plays a role of decarbonizing the agricultural sector using biochar and in production of renewable chemicals [14]. Additionally, several natural organics (cellulose, hemicellulose, lignin, and chitin) [15][16][17] and inorganic (silica) polymers, have been sourced from biomass and used as feedstock for industrial applications [2,18,19].…”

New trends in application of nanotechnology for the pretreatment of lignocellulosic biomass

“…LB is the most abundant organic biomass on the planet, available at a relatively low cost . It was estimated that global production of LB per year is about 1.3 × 10 metric tons.…”

“…LB is the most abundant organic biomass on the planet, available at a relatively low cost . It was estimated that global production of LB per year is about 1.3 × 10 metric tons. Lignocellulose is a heteropolymeric molecule and mainly consists of polymers –cellulose, hemicellulose, and lignin (Fig.…”

Tratamento sequencial químico-enzimático do bagaço de cana-de-açúcar e seu efeito na extração de xilana e na sacarificação da celulose residual

“…Estas enzimas são produzidas principalmente por fungos, bactérias e alguns protozoários(GOLAN, 2011). As celulases são membros da família de enzimas glicosil hidrolases (GH) que catalisam a quebra das ligações glicosídicas da celulose a glicose,(EZEILO et al, 2017;JEOH et al, 2017). Na Tabela 4 encontram-se as principais enzimas envolvidas na hidrólise da celulose.…”