Efficiency and process development for microbial biomass production using oxic bioelectrosynthesis.

Autotrophic microbial electrosynthesis (MES) processes are mainly based on organisms that rely on carbon dioxide (CO) as an electron acceptor and typically have low biomass yields. However, there are few data on the process and efficiencies of oxic MES (OMES). In this study, we used the knallgas bacterium Kyrpidia spormannii to investigate biomass formation and energy efficiency of cathode-dependent growth.

Biological biogas upgrading in a membrane biofilm reactor with and without organic carbon source.

Biogas upgrading is a necessary step to minimize the CO of raw biogas and to make it suitable for gas liquefaction or introduction into the national gas grid. Biomethanation is a promising approach since it converts the CO to more methane on site, while taking advantage of the organisms responsible for biogas production in the first place. This study investigates the suitability of a pseudo-dead-end membrane biofilm reactor (MBfR) for ex-situ biogas upgrading using biogas as sole carbon source as well as for additional acetoclastic methanation when an organic carbon source is provided.

Improving the Cathodic Biofilm Growth Capabilities of EA-1 by Undirected Mutagenesis.

The biotechnological usage of carbon dioxide has become a relevant aim for future processes. Microbial electrosynthesis is a rather new technique to energize biological CO fixation with the advantage to establish a continuous process based on a cathodic biofilm that is supplied with renewable electrical energy as electron and energy source. In this study, the recently characterized cathodic biofilm forming microorganism strain EA-1 was used in an adaptive laboratory evolution experiment to enhance its cathodic biofilm growth capabilities.

A membrane biofilm reactor for hydrogenotrophic methanation.

Biomethanation of CO has been proven to be a feasible way to produce methane with the employment of H as electron source. Subject of the present study is a custom-made membrane biofilm reactor for hydrogenotrophic methanation by archaeal biofilms cultivated on membrane surfaces. Reactor layout was adapted to allow for in situ biofilm analysis via optical coherence tomography.

From an extremophilic community to an electroautotrophic production strain: identifying a novel Knallgas bacterium as cathodic biofilm biocatalyst.

Coupling microbial electrosynthesis to renewable energy sources can provide a promising future technology for carbon dioxide conversion. However, this technology suffers from a limited number of suitable biocatalysts, resulting in a narrow product range. Here, we present the characterization of the first thermoacidophilic electroautotrophic community using chronoamperometric, metagenomic, and C-labeling analyses.