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    University - Student Department: Chemical Engineering Position: Graduate
    University - Student Department: Chemical Engineering Position: Graduate

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All Publications

  • Improved reactor design enables productivity of microbial electrosynthesis on par with classical biotechnology. Bioresource technology Deutzmann, J. S., Callander, G., Spormann, A. M. 2024: 131733

    Abstract

    Microbial electrosynthesis (MES) converts (renewable) electrical energy into CO2-derived chemicals including fuels. To achieve commercial viability of this process, improvements in production rate, energy efficiency, and product titer are imperative. Employing a compact plate reactor with zero gap anode configuration and NiMo-plated reticulated vitreous carbon cathodes substantially improved electrosynthesis rates of methane and acetic acid. Electromethanogenesis rates exceeded 10 L Lcatholyte-1 d-1 using an undefined mixed culture. Continuous thermophilic MES by Thermoanaerobacter kivui produced acetic acid at a rate of up to 3.5 g Lcatholyte-1 h-1 at a titer of 14 g/L, surpassing continuous gas fermentation without biomass retention and on par with glucose fermentation by T. kivui in chemostats. Coulombic efficiencies reached 80 %-90 % and energy efficiencies up to 30 % for acetate and methane production. The performance of this plate-reactor demonstrates that MES can deliver production rates that are competitive with those of established biotechnologies.

    View details for DOI 10.1016/j.biortech.2024.131733

    View details for PubMedID 39486654

  • Alkaline hydrogenotrophic methanogenesis in Methanococcus vannielii at low carbon dioxide concentrations JOURNAL OF CO2 UTILIZATION Callander, G., Deutzmann, J. S., Spormann, A. M. 2024; 83

    View details for DOI 10.1016/j.jcou.2024.102788

    View details for Web of Science ID 001236794000001

  • Low-Cost Clamp-On Photometers (ClampOD) and Tube Photometers (TubeOD) for Online Cell Density Determination. Frontiers in microbiology Deutzmann, J. S., Callander, G., Gu, W., Muller, A. L., McCully, A. L., Ahn, J. K., Kracke, F., Spormann, A. M. 1800; 12: 790576

    Abstract

    Optical density (OD) measurement is the gold standard to estimate microbial cell density in aqueous systems. Recording microbial growth curves is essential to assess substrate utilization, gauge sensitivity to inhibitors or toxins, or determine the perfect sampling point. Manual sampling for cuvette-photometer-based measurements can cause disturbances and impact growth, especially for strictly anaerobic or thermophilic microbes. For slow growing microbes, manual sampling can cause data gaps that complicate analysis. Online OD measurement systems provide a solution, but are often expensive and ill-suited for applications such as monitoring microbial growth in custom or larger anaerobic vessels. Furthermore, growth measurements of thermophilic cultures are limited by the heat sensitivity of complex electronics. Here, we present two simple, low-cost, self-assembled photometers-a "TubeOD" for online measurement of anaerobic and thermophilic cultures in Hungate tubes and a "ClampOD" that can be attached to virtually any transparent growth vessel. Both OD-meters can be calibrated in minutes. We detail the manufacturing and calibration procedure and demonstrate continuous acquisition of high quality cell density data of a variety of microbes, including strict anaerobes, a thermophile, and gas-utilizing strains in various glassware. When calibrated and operated within their detection limits (ca. 0.3-90% of the photosensor voltage range), these self-build OD-meters can be used for continuous measurement of microbial growth in a variety of applications, thereby, simplifying and enhancing everyday lab operations.

    View details for DOI 10.3389/fmicb.2021.790576

    View details for PubMedID 35095803