title: Mechanistic investigation in ultrasound induced enhancement of enzymatic hydrolysis of invasive biomass species.
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.
authors.affiliation: Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Arup Jyoti
authors.initials: AJ
authors.lastname: Borah
authors.affiliation: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Mayank
authors.initials: M
authors.lastname: Agarwal
authors.affiliation: Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur 784028, Assam, India.
authors.forename: Manisha
authors.initials: M
authors.lastname: Poudyal
authors.affiliation: Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India; Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors.forename: Arun
authors.initials: A
authors.lastname: Goyal
authors.affiliation: Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India; Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India. Electronic address: vmoholkar@iitg.ernet.in.
authors.forename: Vijayanand S
authors.initials: VS
authors.lastname: Moholkar
mesh_terms: D000465:Algorithms; D000818:Animals; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D002942:Circular Dichroism; D031806:Eichhornia / Q000737:chemistry / Q000378:metabolism; D005285:Fermentation; D006868:Hydrolysis; D058865:Introduced Species; D007700:Kinetics; D032410:Lantana / Q000737:chemistry / Q000378:metabolism; D035742:Mikania / Q000737:chemistry / Q000378:metabolism; D008962:Models, Theoretical; D057685:Plant Weeds / Q000737:chemistry / Q000378:metabolism*; D031786:Saccharum / Q000737:chemistry / Q000378:metabolism; D013010:Sonication; D014465:Ultrasonics / Q000379:methods*
keywords: Cavitation; Conformational change; Enzymatic hydrolysis; Genetic Algorithm; Ultrasound