Mechanistic insights bidirectional extracellular electron transfer driving synchronous nitrogen fixation in Klebsiella variicola

ABSTRACT: Microorganisms can function as anode catalysts to achieve biological nitrogen fixation while simultaneously generating bioelectricity. To date, only a limited number of microorganisms are capable of performing both outward and inward extracellular electron transfer (EET) concurrently. However, the variations in nitrogen fixation performance and underlying mechanisms during bidirectional EET remain poorly understood. Here, we isolated a nitrogen-fixing bacterium, Klebsiella variicola C1, which exhibits the ability for bidirectional electron transfer. Three-dimensional fluorescence and cyclic voltammetry analyses uncovered distinct differences in biofilm compositions at the anode and cathode. Fluorescence quantitative PCR and comparative proteomics highlighted specific distinctions in key genes and proteins associated with outward and inward EET processes. Outer-membrane lipoprotein carrier proteins likely play a primary role in outward electron transfer, whereas pilus proteins may predominantly facilitate inwa

ORGANISM(S): Klebsiella Variicola Uci 18

SUBMITTER: Peng Li  

PROVIDER: PXD071420 | iProX | Mon Dec 01 00:00:00 GMT 2025

REPOSITORIES: iProX