Mechanistic investigation in ultrasound induced enhancement of enzymatic hydrolysis of invasive biomass species

Arup Jyoti Borah; Mayank Agarwal; Manisha Poudyal; Arun Goyal; Vijayanand S Moholkar

doi:10.1016/j.biortech.2016.02.024

Mechanistic investigation in ultrasound induced enhancement of enzymatic hydrolysis of invasive biomass species

Bioresour Technol. 2016 Aug:213:342-349. doi: 10.1016/j.biortech.2016.02.024. Epub 2016 Feb 11.

Authors

Arup Jyoti Borah¹, Mayank Agarwal², Manisha Poudyal³, Arun Goyal⁴, Vijayanand S Moholkar⁵

Affiliations

¹ Center for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
² Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
³ Department of Molecular Biology and Biotechnology, Tezpur University, Napaam, Tezpur 784028, Assam, India.
⁴ 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.
⁵ 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.

PMID: 26898160
DOI: 10.1016/j.biortech.2016.02.024

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.

Keywords: Cavitation; Conformational change; Enzymatic hydrolysis; Genetic Algorithm; Ultrasound.

MeSH terms

Algorithms
Animals
Biomass
Biotechnology / methods*
Circular Dichroism
Eichhornia / chemistry
Eichhornia / metabolism
Fermentation
Hydrolysis
Introduced Species*
Kinetics
Lantana / chemistry
Lantana / metabolism
Mikania / chemistry
Mikania / metabolism
Models, Theoretical
Plant Weeds / chemistry
Plant Weeds / metabolism*
Saccharum / chemistry
Saccharum / metabolism
Sonication
Ultrasonics / methods*