Switchgrass (Panicum virgatum) Fermentation by Clostridium thermocellum and Clostridium saccharoperbutylacetonicum Sequential Culture in a Continuous Flow Reactor

Authors

Noelia M. Elia, University of KentuckyFollow
Sue E. Nokes, University of KentuckyFollow
Michael D. Flythe, University of KentuckyFollow

Abstract

The study was conducted to evaluate fermentation by Clostridium thermocellum and C. saccharoperbutylacetonicum in a continuous-flow, high-solids reactor. Liquid medium was continuously flowed through switchgrass (2 mm particle size) at one of three flow rates: 83.33 mL h⁻¹ (2 L d⁻¹), 41.66 mL h⁻¹ (1 L d⁻¹), and 20.833 mL h⁻¹ (0.5 L d⁻¹). The cellulolytic phase was initiated by culturing C. thermocellum (63 °C, 24 h). The temperature was decreased (35) and C. saccharoperbutylacetonicum was inoculated. When metabolism decreased (96 h), the temperature was increased (63 °C; 24 h) to permit cellulosome production by C. thermocellum. The C. saccharoperbutylacetonicum was re-inoculated and the temperature returned to 35°C. The average gross production over 9 d was 1480 mg total acids (formic, acetic lactic butyric), 207 mg total solvents (acetone, butanol, ethanol), and average dry matter disappearance was 2.8 g from 25 g non-pretreated switchgrass. There was no effect of flow rate on the product formation. These results indicate that C. thermocellum can survive and produce cellulases with C. saccharoperbutylacetonicumin a continuous-flow, high-solids reactor temperature with temperature cycling.

Document Type

Article

Publication Date

1-19-2016

Notes/Citation Information

Published in AIMS Energy, v. 4, no. 1, p. 95-103.

© 2016 Michael Flythe et al., licensee AIMS Press.

This is an open access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0).

Digital Object Identifier (DOI)

https://doi.org/10.3934/energy.2016.1.95

Funding Information

United States Department of Agriculture National Institute for Food and Agriculture Biomass Research and Development Initiative (Grant number #2011-10006-30363) funded the research.

Repository Citation

Elia, Noelia M.; Nokes, Sue E.; and Flythe, Michael D., "Switchgrass (Panicum virgatum) Fermentation by Clostridium thermocellum and Clostridium saccharoperbutylacetonicum Sequential Culture in a Continuous Flow Reactor" (2016). Biosystems and Agricultural Engineering Faculty Publications. 12.
https://uknowledge.uky.edu/bae_facpub/12