Coupled Electrochemical and Microbial Catalysis for the Production of Polymer Bricks

Abstract

Power-to-X technologies have the potential to pave the way towards a future resource-secure bioeconomy as they enable the exploitation of renewable resources and CO 2. Herein, the coupled electrocatalytic and microbial catalysis of the C 5polymer precursors mesaconate and 2S-methylsuccinate from CO 2 and electric energy by in situ coupling electrochemical and microbial catalysis at 1 L-scale was developed. In the first phase, 6.1 � 2.5 mm formate was produced by electrochemical CO 2 reduction. In the second phase, formate served as the substrate for microbial catalysis by an engineered strain of Methylobacterium extorquens AM-1 producing 7 � 2 μm and 10 � 5 μm of mesaconate and 2S-methylsuccinate, respectively. The proof of concept showed an overall conversion efficiency of 0.2 % being 0.4 % of the theoretical maximum.

Systems-informed genome mining for electroautotrophic microbial production

“…(23), and to reduce NO3to nitrite (NO2 -) using, e.g. the Nar complex 13 : NO 3 − + 2H + + QH 2 → NO 2 − + H 2 O + Q + 2H + out (25) Further reactions consume electrons liberated by quinol oxidation to complete the reduction of NO2to N2 13 :…”

Catalytic Cooperation between a Copper Oxide Electrocatalyst and a Microbial Community for Microbial Electrosynthesis

“…[48] For example, a CuSn 3 alloy catalyst has been recently shown to achieve 95 % selectivity for formate production at high current density and low overpotential, with no evident loss of activity after 50 hours. [49] Importantly, metals such as copper and tin are much more competitive in terms of price than indium, which has been previously used for co-catalytic reactions with MES, [18][19][20][21] with an estimated price of over 20 or 8 times lower than indium, respectively. [50] Therefore, a co-catalytic process based on supported copper nanostructures or alloys of copper would be more applicable, and effectively use smaller amounts of metal catalyst, while it has the potential to increase the biocompatibility of the electrode, by using carbonaceous support materials.…”

“…[19] Hegner and co-workers investigated the combination of Indium-electrocatalysed formate production and microbial utilization in a two-step reaction, wherein genetically engineered strains of Methylobacterium extorquens AM-1 were introduced in the reactor after formate production, and were able to deplete formate, forming mesaconate and methylsuccinate. [20] Similar studies have also been performed using non-genetically engineered microorganisms, namely Methylobacterium extorquens AM1 and Cupriavidus necator H16, to produce Poly(3-hydroxybutyrate) (PHB) from in situ electrochemically generated formate, in combination with an indium electrocatalyst. [21] These studies demonstrate that a syntrophic relationship based on formate between metal electrocatalysts and biocatalysts is possible in one reactor.…”

A Comprehensive Modeling Analysis of Formate‐Mediated Microbial Electrosynthesis**

“…Several groups have developed prototypical systems for mediated MES, relying on various redox mediators including H 2 , [6–9] inorganic ions (e. g., ferrous ions or ammonia), [10,11] simple organic molecules (e. g., carbon monoxide, formate, and methanol), [12–15] and complex organic molecules such as the dye neutral red [16,17] . Although these prototype systems have been able to achieve high efficiencies (∼10 % in the case of Wang et al [8] …”