Dependence of Enzymatic Saccharification on the Type of Biomass and Pretreatment

Variety of agricultural crops and other forest residues form an important lignocellulosic biomass feedstock for biorefineries. However, these lignocellulosic biomasses differ in their structure in terms of composition and steric orientation of constituent polymers (cellulose, hemicellulose, and lignin). The bioconversion of these lignocellulosic biomasses involves different pretreatment methods including steam explosion, dilute acid/alkali, liquid hot water, and ammonia fiber explosion that are distinct in their operational parameters. During pretreatment, lignocellulosic biomass undergoes significant structural rearrangements, which pose numerous challenges for subsequent enzymatic saccharification. Owing to these changes, a diverse suite of carbohydrate active enzymes (CAZymes) mainly glycosyl hydrolase, auxiliary enzymes, carbohydrate esterase, and other accessory proteins is required for custom designing of lignocellulolytic enzyme cocktails. Current approaches include identifying catalytically active, robust CAZymes, exploiting natural strains, and vast genome databases for bioprospecting for efficient enzyme cocktails, which can be useful in saccharification of biorefinery-relevant lignocellulosic biomass.