Mechanistic investigation in ultrasound induced enhancement of enzymatic hydrolysis of invasive biomass species. (August 2016)

• Record Type: Journal Article
• Authors: Borah, Arup Jyoti; Agarwal, Mayank; Poudyal, Manisha; Goyal, Arun; Moholkar, Vijayanand S.
• Is Part Of: Bioresource technology. Volume 213(2016)
• Page Start: 342
• Page End: 349
• Publication Date: 2016-08
• Subjects: Enzymatic hydrolysis -- Ultrasound -- Cavitation -- Conformational change -- Genetic Algorithm; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2016.02.024
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Enzymatic hydrolysis of four invasive weeds with mechanical agitation and sonication. Experimental results fitted to HCH-1 model of hydrolysis using Genetic Algorithm. Sonication enhances kinetics of enzymatic hydrolysis by more than 10-fold. Sonication augments enzyme activity by conformational changes in secondary structure. Reduction in product inhibition and increase in substrate affinity of enzyme by sonication. Abstract: This study has assessed four invasive weeds, viz. Saccharum spontaneum (SS), Mikania micrantha (MM), Lantana camara (LC) and Eichhornia crassipes (EC) for enzymatic hydrolysis prior to bioalcohol fermentation. Enzymatic hydrolysis of pretreated biomasses of weeds has been conducted with mechanical agitation and sonication under constant (non-optimum) conditions. Profiles of total reducible sugar release have been fitted to HCH-1 model of enzymatic hydrolysis using Genetic Algorithm. Trends in parameters of this model reveal physical mechanism of ultrasound-induced enhancement of enzymatic hydrolysis. Sonication accelerates hydrolysis kinetics by ∼10-fold. This effect is contributed by several causes, attributed to intense micro-convection generated during sonication: (1) increase in reaction velocity, (2) increase in enzyme–substrate affinity, (3) reduction in product inhibition, and (4) enhancement of enzyme activity due to conformational changes in its secondary structure. Enhancement effect of sonication is revealed to be independent of conditions of enzymatic hydrolysis – whether optimum or non-optimum.