Mineral triboelectricity as an electron source for microbial autotrophy: implications for carbon and nitrogen cycling in energy-limited environments

Triboelectrification converts mechanical contact and separation into interfacial charge, yet whether mineral-derived triboelectric electrons can sustain microbial growth and metabolism remains unclear. Here, we report a mechanically powered autotrophic pathway in which mineral-mediated triboelectrification converts mechanical energy into an extracellular electron supply. Within the α-Fe₂O₃-Rhodopseudomonas palustris biohybrid, triboelectrically generated electrons were routed through cell-envelope redox conduits into respiratory metabolism, thereby converting interfacial charge into cellular energy and reducing power. This bioenergetic conversion coupled inorganic carbon fixation to nitrate respiration, sustaining autotrophic growth and lycopene biosynthesis in the dark without conventional chemical electron donors. Its compatibility with distinct mechanical inputs, electroactive microorganisms, and terminal electron acceptors demonstrates the broad adaptability of this energy-coupling pathway, whereas mineral-dependent performance identifies interfacial charge generation as an important control on microbial electron supply. These findings identify mineral-solid triboelectric contact as a distinct interfacial route linking mechanical energy to microbial carbon and nitrogen transformations, highlighting its potential relevance to biogeochemical processes in energy-limited environments.