Adsorption of cellulase on cellulose: Effect of physicochemical properties of cellulose on adsorption and rate of hydrolysis

Abstract

summaryIn the cellulase-cellulose reaction system. the adsorption of cellulase on the solid cellulose substrate was found to be one of the important parameters that govern the enzymatic hydrolysis rate of cellulose. The adsorption of cellulase usua!!y parallels the rate of hydrolysis of cellulose. The affinity for cellulase varies depecding on the structural properties of cellulose. Adsorption parameters such as the half-saturation constant, the maximum adsorption constant, and the distribution coefficient for both the cellulase and cellulose have been experimentally determined for several substrates. These adsorption parameters vary with the source of cellulose and the pretreatment methods and are correlated with the crystallinity and the specific surface area of cellulose substrates. The changing pattern of adsorption profile of cellulase during the hydrolysis reaction has also been elucidated. For practical utilization of cellulosic materials. the cellulose structural properties and their effects on cellulase adsorption, and the rate of hydrolysis must be taken into consideration.

Enzymatically-Mediated Co-Production of Cellulose Nanocrystals and Fermentable Sugars

“…The enzyme loading at the point when glucose yield started to plateau, with no further significant increase in yield at subsequent loadings, was identified as the most effective cellulase cocktail dosage. At this point, all of the enzyme-accessible binding sites would have been saturated [46]. Further addition of enzyme protein would not contribute to cellulose hydrolysis and only incur unnecessary cost to the process.…”

Use of Sugarcane Bagasse with Different Particle Sizes to Determine the Relationship between Physical Properties and Enzymatic Hydrolysis

“…Lignocellulose must be hydrolyzed before it can be converted into fuels by fermentation. The efficient hydrolysis of lignocellulosic materials requires an effective pretreatment to change the structure, chemical composition, degree of polymerization, crystallinity, specific surface area, and enzyme adsorption capacity of the selected material (Lee et al 1982;Yeh et al 2010;Del Rio et al 2012). It is difficult to determine which of these factors has the greatest impact on the enzymatic hydrolysis of a lignocellulosic biomass, as almost all of them change during chemical pretreatments (Lee et al 1982;Mansfield et al 1999;Kumar and Wyman 2009;Li et al 2014b).…”

“…Cellulase adsorption on cellulose is important for hydrolysis (Lee et al 1982;Klyosov et al 1986;Piccolo et al 2010;Wiman et al 2012). However, pretreatments alter many parameters, such as the chemical composition and the supramolecular structure, and it is difficult to discern which changes lead to enhanced enzymatic conversion.…”

İzobütan Dehi̇drojenasyonu İçi̇n Reaksi̇yon Mekani̇zmasinin Araştirilmasi

“…Hız değerlerinin konsantrasyonla artması, reaksiyon için adsorpsiyon basamağının önemli olmadığını göstermiştir. Reaksiyon için adsorpsiyonun önemli olması durumunda, önce daha küçük eğimde reaksiyon hızlarının yavaş bir şekilde artması, adsorpsiyon dengesine ulaşıldığında reaksiyon hızının bir süre sabitlenmesi ve sonrasında adsorplanmış katalizör yüzeyinin kademeli olarak serbest kalmasına bağlı olarak reaksiyon hızının azalış göstermesi şeklinde bir değişim olması gerekmektedir [16,17]. Katalizör üzerinde izobütan dehidrojenasyon reaksiyonu için izobütan adsorpsiyonunun hızlı bir şekilde gerçekleştiği öngörülerek çok sayıda reaksiyon mekanizması arasından yüzey reaksiyonun kontrolünü öne çıkaran basit mekanizmalar (Model I & Model II) üzerinde çalışılmasına karar verilmiştir.…”