Self-cycling Fermentation for Ethanol Production

Jie Wang1, Michael Chae1, Dominic Sauvageau2 and David C. Bressler1.
1Department of Agricultural, Food and Nutritional Science, University of Alberta, Edmonton, Alberta, Canada.
2Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta, Canada.

This project aims at applying self-cycling fermentation (SCF) into industrial ethanol production to improve ethanol yield and productivity beyond the levels achieved in current methodologies. SCF is a cycling processing strategy that can be applied to cultivate synchronous cell populations at large scale. This mode of operation has been shown to increase product yield and/or productivity in many microbial production systems compared with conventional fermentation modes, such as batch, fed-batch, or continuous operation1–4. The research presented here will assess parameters such as pH, redox potential, and carbon dioxide evolution rate to determine whether they can serve as a real-time parameter to indicate the growth transition of yeast cells from exponential to stationary phase. Determination of such a parameter will enable us to design a SCF system whereby half the volume of the broth will be removed and replaced with fresh medium once cells enter stationary phase. In this way, yeast cells will be synchronized thereby increasing ethanol yields and productivity. Successful application of SCF to current ethanol production strategies would make ethanol production more cost effective and help strengthen the ethanol industry.


1. S. D. Wentworth and D. G. Cooper, J. Ferment. Bioeng., 1996, 81, 400–405.

2. Z. J. Storms, T. Brown, D. Sauvageau and D. G. Cooper, Biotechnol. Bioeng., 2012, 109, 2262–2270.

3. W. a. Brown and D. G. Cooper, Appl. Environ. Microbiol., 1991, 57, 2901–2906.

4. R. V. Agustin, University of Alberta, 2015.