Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1016/j.watres.2023.120279
Title (Primary) Comparing theoretical and practical biomass yields calls for revisiting thermodynamic growth models for electroactive microorganisms
Author Korth, B. ORCID logo ; Pereira, J.; Sleutels, T.; Harnisch, F. ORCID logo ; ter Heijne, A.
Source Titel Water Research
Year 2023
Department UMB
Volume 242
Page From art. 120279
Language englisch
Topic T7 Bioeconomy
Keywords Electroactive microorganisms; Extracellular electron transfer; Thermodynamic modeling; Biomass yield; Restricted energy harvest; Microbial electrochemical technologies
Abstract Research on electroactive microorganisms (EAM) often focuses either on their physiology and the underlying mechanisms of extracellular electron transfer or on their application in microbial electrochemical technologies (MET). Thermodynamic understanding of energy conversions related to growth and activity of EAM has received only a little attention. In this study, we aimed to prove the hypothesized restricted energy harvest of EAM by determining biomass yields by monitoring growth of acetate-fed biofilms presumably enriched in Geobacter, using optical coherence tomography, at three anode potentials and four acetate concentrations. Experiments were concurrently simulated using a refined thermodynamic model for EAM. Neither clear correlations were observed between biomass yield and anode potential nor acetate concentration, albeit the statistical significances are limited, mainly due to the observed experimental variances. The experimental biomass yield based on acetate consumption ( = 37 ± 9 mgCODbiomass gCODac−1) was higher than estimated by modeling, indicating limitations of existing growth models to predict yields of EAM. In contrast, the modeled biomass yield based on catabolic energy harvest was higher than the biomass yield from experimental data ( = 25.9 ± 6.8 mgCODbiomass kJ−1), supporting restricted energy harvest of EAM and indicating a role of not considered energy sinks. This calls for an adjusted growth model for EAM, including, e.g., the microbial electrochemical Peltier heat to improve the understanding and modeling of their energy metabolism. Furthermore, the reported biomass yields are important parameters to design strategies for influencing the interactions between EAM and other microorganisms and allowing more realistic feasibility assessments of MET.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=27285
Korth, B., Pereira, J., Sleutels, T., Harnisch, F., ter Heijne, A. (2023):
Comparing theoretical and practical biomass yields calls for revisiting thermodynamic growth models for electroactive microorganisms
Water Res. 242 , art. 120279 10.1016/j.watres.2023.120279