Table of Contents
Journal of Fuels
Volume 2014, Article ID 419674, 11 pages
Research Article

Statistical Optimization of Fermentation Process Parameters by Taguchi Orthogonal Array Design for Improved Bioethanol Production

Department of Biotechnology, Indian Institute of Technology Guwahati, Guwahati, Assam 781 039, India

Received 31 March 2013; Accepted 10 October 2013; Published 14 January 2014

Academic Editors: A. Ficarella, A. W. Mohammad, B. Moreno, and C. Mortalò

Copyright © 2014 Saprativ P. Das et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The statistical optimization of different fermentation process parameters in SSF of mixed MAA and organosolv pretreated 1% (w v−1) wild grass, namely, recombinant Clostridium thermocellum hydrolytic enzymes’ volume (GH5 cellulase, GH43 hemicellulase), fermentative microbes’ inoculum volume (Saccharomyces cerevisiae, Candida shehatae), pH, and temperature, was accomplished by Taguchi orthogonal array design. The optimized parameters in 100 mL of fermentation medium were (%, v v−1) as follows: 1.0, recombinant GH5 cellulase (5.7 mg−1, 0.45 mg mL−1); 2.0, recombinant GH43 hemicellulase (3.7 U mg−1, 0.32 mg mL−1); 1.5, S. cerevisiae (3.9 × 108 cells mL−1); 0.25, C. shehatae (2.7 × 107 cells mL−1); pH, 4.3; and temperature, 35C. pH with p-value 0.001 was found to be the most significant factor affecting SSF. The ethanol titre obtained in Taguchi optimized shake flask SSF was 2.0 g L−1 implying a 1.3-fold increase as compared to ethanol titre of 1.5 g L−1 in unoptimized shake flask SSF. A 1.5-fold gain in ethanol titre (3.1 g L−1) was obtained with the same substrate concentration in lab scale bioreactor on scaling up the shake flask SSF with Taguchi optimized process parameters.