Abstract
Acetogen strain Clostridium sp. MT1121 produced 300 mM acetate (p < 0.005) and 321 mM ethanol (p < 0.005) from synthesis gas (syngas) blend 60 % CO and 40 % H2. Clostridium sp. MT1121 was metabolically engineered to eliminate production of either acetate or acetaldehyde during syngas fermentation. We used Cre-lox66/lox71-based gene removal system to eliminate either phosphotransacetylase (pta), or acetaldehyde dehydrogenase (aldh). The resulted biocatalyst with eliminated pta increased ethanol yield to 610 mM (p < 0.005). Inactivation of pta rendered only 502 mM of ethanol (p < 0.005). The acetogen biocatalyst with eliminated aldh produced 450 mM acetate (p < 0.005). The role of cell energy pool preservation for re-directed carbon flux is discussed. This is the first report on time- and cost-efficient gene elimination in acetogens using lox66/lox71 gene elimination system.
Similar content being viewed by others
References
Demain, A. L. (2009). Journal of Industrial Microbiology und Biotechnology, 36(3), 319–332.
Fischer, C. R., Klein-Marcuschamer, D., & Stephanopoulos, G. (2008). Metabolic Engineering, 10(6), 295–304.
Köpke, M., Michalcea, C., Liew, F.-M., Tizard, J. H., Ali, M. S., Conolly, J. J., et al. (2011). Applied Environmental Microbiology, 77(15), 5467–5475.
Abubackar, N. H., Veiga, M. C., & Kennes, C. (2011). Biofuels, Bioproducts and Biorefining, 5(1), 93–114.
Gaddy, J. L., Arora, D. D., Ko, C.-W., Phillips, J. R., Basu, R., Wikstrom, C.V., et al. (2001). Methods for increasing the production of ethanol from microbial fermentation. US Patent 7285402.
Tyurin, M., Kiryukhin, M., & Berzin, V. (2012). Journal of Biotech Research, 4, 1–12.
Paul, D., Austin, F. W., Arick, T., Bridges, S. M., Burgess, S. C., Dandass, Y. S., et al. (2010). Journal of Bacteriology, 192(20), 5554–5555.
Leibig, M., Krismer, B., Kolb, M., Friede, A., Götz, F., & Bertram, R. (2008). Applied and Environmental Microbiology, 74(5), 1316–1323.
Tanner, R. S., Miller, L. M., & Yang, D. (1993). International Journal of Systematic Bacteriology, 43(2), 232–236.
Tyurin, M. V. (1992). The method and apparatus for electric cell treatment using partial capacitor discharge via the sample and the power tetrode. Russian Patent 2005776.
Tyurin, M. V., Desai, S. G., & Lynd, L. R. (2004). Applied and Environmental Microbiology, 70, 883–890.
Tyurin, M. V., Sullivan, C. R., & Lynd, L. R. (2005). Applied and Environmental Microbiology, 71, 8069–8076.
Berzin, V., & Tyurin, M. (2012). Journal of Biotech Research, 4, 54–64.
Ross, S. M. (2000). Introduction to probability and statistics for engineers and scientists (2nd ed.). San Diego: Academic Press, Inc.
Acknowledgments
The research was supported by the funds of Syngas Biofuels Energy, Inc.
Syngas Biofuels Energy, Inc. is the sole distributor of the electroporation and electrofusion equipment: www.syngasbiofuelsenergy.com.
Conflict of Interest
The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Berzin, V., Kiriukhin, M. & Tyurin, M. Cre-lox66/lox71-Based Elimination of Phosphotransacetylase or Acetaldehyde Dehydrogenase Shifted Carbon Flux in Acetogen Rendering Selective Overproduction of Ethanol or Acetate. Appl Biochem Biotechnol 168, 1384–1393 (2012). https://doi.org/10.1007/s12010-012-9864-8
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12010-012-9864-8