(438f) Expanding Whole Cell Catalysis Using Extracellular Electron Transfer | AIChE

(438f) Expanding Whole Cell Catalysis Using Extracellular Electron Transfer


Keitz, B. K. - Presenter, The University of Texas at Austin
Fan, G., University of Texas at Austin
Dundas, C., University of Texas at Austin
Graham, A. J., University of Texas at Austin
Metabolic engineering and whole-cell catalysis has facilitated the production of pharmaceuticals, fuels, and soft materials but is generally limited to well-defined metabolic pathways. Here, we'll discuss how extracellular electron transfer (EET) can be leveraged to expand the reaction scope of microbial catalysis by coupling metabolism to an extracellular catalytic cycle.1 Specifically, we used the model electrogen Shewanella oneidensis to power a living radical polymerization via electron transfer to a metal catalyst. Using S. oneidensis, we achieved precise control over the molecular weight and polydispersity of a bioorthogonal polymer while non-electroactive organisms, such as E. coli, showed no significant activity. We also found that polymerization performance was a strong function of catalyst structure, bacterial metabolism, and specific electron transfer proteins. Finally, we describe how polymerization can be used to control hydrogel cross-linking in a genotypic-specific manner as well as our initial efforts to transcriptionally regulate relative flux through EET pathways. Overall, our results suggest that manipulating extracellular electron transfer pathways may be a general strategy for expanding the synthetic reaction space available to microbes.

1. G. Fan, C. M. Dundas, A. J. Graham, N. A. Lynd, B. K. Keitz,* “Shewanella oneidensis as a Living Electrode for Controlled Radical Polymerization” Proc. Natl. Acad. Sci. U.S.A., 2018, 115, 4559-4564.