title: Mechanistic insight into ultrasound induced enhancement of simultaneous saccharification and fermentation of Parthenium hysterophorus for ethanol production.
abstract: This paper presents investigations into mechanism of ultrasound assisted bioethanol synthesis using Parthenium hysterophorus biomass through simultaneous saccharification and fermentation (SSF) mode. Approach of coupling experimental results to mathematical model for SSF using Genetic Algorithm based optimization has been adopted. Comparison of model parameters for experiments with mechanical shaking and sonication (10% duty cycle) give an interesting mechanistic account of influence of ultrasound on SSF system. A 4-fold rise in ethanol and cell mass productivity is seen with ultrasound. The analysis reveals following facets of influence of ultrasound on SSF: increase in Monod constant for glucose for cell growth, maximal specific growth rate and inhibition constant of cell growth by glucose and reduction in specific cell death rate. Values of inhibition constant of cell growth by ethanol (K3E), and constants for growth associated (a) and non-growth associated (b) ethanol production remained unaltered with sonication. Beneficial effects of ultrasound are attributed to enhanced cellulose hydrolysis, enhanced trans-membrane transport of substrate and products as well as dilution of the toxic substances due to micro-convection induced by ultrasound. Intrinsic physiological functioning of cells remained unaffected by ultrasound as indicated by unaltered values of K3E, a and b.
authors: Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors: Shuchi
authors: S
authors: Singh
authors: Department of Chemical Engineering, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors: Mayank
authors: M
authors: Agarwal
authors: Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India.
authors: Shyamali
authors: S
authors: Sarma
authors: Centre for Energy, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India; Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati 781 039, Assam, India. Electronic address: arungoyl@iitg.ernet.in.
authors: Arun
authors: A
authors: Goyal
authors: Centre 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: Vijayanand S
authors: VS
authors: Moholkar
mesh_terms: D019659:Asteraceae / Q000737:chemistry*; D018533:Biomass; D001709:Biotechnology / Q000379:methods*; D050260:Carbohydrate Metabolism; D002470:Cell Survival; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism; D013010:Sonication
chemical_list: D000431:Ethanol
keywords: Bioethanol; Fermentation; Mathematical modeling; Microturbulence; Parthenium hysterophorus; Ultrasound