DBFZ Deutsches Biomasseforschungszentrum gemeinnützige GmbH (German Biomass Research Centre), Department of Biochemical Conversion, 04347, Leipzig, Germany.
SINTEF Industry, Department of Biotechnology and Nanomedicine, 7034, Trondheim, Norway.
NPJ Biofilms Microbiomes. 2024 Mar 5;10(1):17. doi: 10.1038/s41522-024-00490-z.
Combining anaerobic digestion (AD) and microbial electrochemical technologies (MET) in AD-MET holds great potential. Methanogens have been identified as one cause of decreased electrochemical activity and deterioration of Geobacter spp. biofilm anodes. A better understanding of the different interactions between methanogenic genera/species and Geobacter spp. biofilms is needed to shed light on the observed reduction in electrochemical activity and stability of Geobacter spp. dominated biofilms as well as observed changes in microbial communities of AD-MET. Here, we have analyzed electrochemical parameters and changes in the microbial community of Geobacter spp. biofilm anodes when exposed to three representative methanogens with different metabolic pathways, i.e., Methanosarcina barkeri, Methanobacterium formicicum, and Methanothrix soehngenii. M. barkeri negatively affected the performance and stability of Geobacter spp. biofilm anodes only in the initial batches. In contrast, M. formicicum did not affect the stability of Geobacter spp. biofilm anodes but caused a decrease in maximum current density of ~37%. M. soehngenii induced a coloration change of Geobacter spp. biofilm anodes and a decrease in the total transferred charge by ~40%. Characterization of biofilm samples after each experiment by 16S rRNA metabarcoding, whole metagenome nanopore sequencing, and shotgun sequencing showed a higher relative abundance of Geobacter spp. after exposure to M. barkeri as opposed to M. formicicum or M. soehngenii, despite the massive biofilm dispersal observed during initial exposure to M. barkeri.
在 AD-MET 中结合厌氧消化 (AD) 和微生物电化学技术 (MET) 具有很大的潜力。产甲烷菌已被确定为降低电化学活性和破坏 Geobacter spp.生物膜阳极的一个原因。需要更好地了解产甲烷菌属/种与 Geobacter spp.生物膜之间的不同相互作用，以阐明观察到的 Geobacter spp.占主导地位的生物膜的电化学活性和稳定性降低，以及 AD-MET 中微生物群落的观察到的变化。在这里，我们分析了电化学参数和暴露于三种具有不同代谢途径的代表性产甲烷菌（即 Methanosarcina barkeri、Methanobacterium formicicum 和 Methanothrix soehngenii）时 Geobacter spp.生物膜阳极的微生物群落变化。M. barkeri 仅在初始批次中对 Geobacter spp.生物膜阳极的性能和稳定性产生负面影响。相比之下，M. formicicum 不会影响 Geobacter spp.生物膜阳极的稳定性，但会导致最大电流密度降低约 37%。M. soehngenii 导致 Geobacter spp.生物膜阳极变色，并使总转移电荷量减少约 40%。通过 16S rRNA 代谢组学、全基因组纳米孔测序和鸟枪法测序对每次实验后的生物膜样品进行表征，结果表明，与 M. formicicum 或 M. soehngenii 相比，暴露于 M. barkeri 后 Geobacter spp.的相对丰度更高，尽管在最初暴露于 M. barkeri 时观察到大量生物膜分散。
