Z-Fuels

The concept is to design, construct and operate a bacterial process with an intregrated Microbubble distillation to convert low value waste - crude glycerol and molasses - into high value chemicals that serve as precursors for biofuels.

Butanol is a desirable biofuel as its characteristics most closely match gasoline and allows using current gasoline fuel infrastruture and vehicles. Its production however is limited by the energy requirements needed for its synthesis from ethanol and the poor yields. The idea of this project is, therefore, the biotechnologial production of acetaldehyde, a known intermediate of the synthesis of butanol from ethanol, using the genetically engineered bacterium Zymomonas mobilis.

At the Institute for System Dynamics both stoichiometric and kinetic models of the central metabolism of Zymomonas mobilis are developed and genetic intervention strategies for better acetaldehyde yields and usability of a broader spectrum of substrates are predicted. Futhermore, acetaldehyde acts as strong metabolic inhibitor already at low concentrations. The biotechnologcial sysnthesis of acetaldehyde should, therfore, be integrated with a microbubble distillation system ensuring effective removal of acetaldehyde during the metabolic process. This will alleviate the inhibition and give higher yields. From the higher production quantities of acetaldehyde a more competitive and efficient route to butanol production can be obtained compared to current practise.

• Perlemax Limited, Graeme Hitchen, Sheffield, UK
• Institute of Microbiology and Biotechnology, Uldis Kalnenieks, University of Latvia, Riga
• Department of Biotechnology, Per Bruheim, NTNU Norwegian University of Science and Technology, Trondheim, Norway
• Max-Planck-Institute for Dynamics and Complex Technical Systems, Katja Bettenbrock, Magedburg, Germany

• Kalnenieks, E. Balodite, S. Strähler, I. Strazdina, J. Rex, A. Pentjuss, K. Fuchino, P. Bruheim, R. Rutkis, K. M. Pappas, R. K. Poole, O. Sawodny, K. Bettenbrock, „Improvement of acetaldehyde production in Zymomonas mobilis by engineering of its aerobic metabolism”. Frontiers in Microbiology, 2019, doi: 10.3389/fmicb.2019.02533