Eukaryote–Bacterial Symbiont Electrotrophy: A 2008 Concept and Updated Technical Commentary

This work proposes a novel alternative to conventional microbial electrosynthesis: a small, multicellular animal hosting chemoautotrophic bacterial symbionts, progressively coupled to use electricity for carbon fixation and the production of useful organic compounds. Unlike conventional bacterial biofilms, the proposed electrotrophic animal could protect and regulate its symbionts to maintain desirable production traits, actively manage electrode contact, and package valuable products into easily harvested structures. These advantages may address major limitations of bacterial electrosynthesis, particularly long-term production stability, biological optimization, and costly product recovery. If successful, this approach could establish a versatile, potentially more economical platform for converting electricity and CO₂ into useful biological products. The accompanying technical commentary examines biological precedents, electron-transfer pathways, quantitative feasibility, and a proposed experimental selection strategy for the eukaryotic host–microbial symbiont system. It also explores a hypothetical underground ecological niche that might favor the evolutionary maintenance of a novel light-independent (“dark”) water-oxidation mechanism in certain geomicrobes, and proposes an alternative sulfur-granule electron-storage mechanism that might serve the same ecological niche. Both hypotheses yield specific, testable predictions. The archive also contains images of the author's original 2008 notebook entry, which independently anticipated microbial electrosynthesis approximately two years before its experimental demonstration. A historical account also describes a conversation the author had at the time. Publishing these historical materials is intended solely to enrich the record of scientific history, and is not meant to diminish the work of others in any way. Independent discoveries and rediscoveries, such as the author's, are surprisingly common in science.