Wiring Up Along Electrodes for Biofilm Formation

Frontiers in Microbiology

María Belén Prados¹  Mariela Lescano¹  Gustavo Curutchet²  Natalia Porzionato² 

[1] Instituto de Energía y Desarrollo Sustentable, Centro Atómico Bariloche, Comisión Nacional de Energía Atómica, Buenos Aires, Argentina;Instituto de Investigaciones e Ingeniería Ambiental y Escuela de Ciencia y Tecnología, Universidad Nacional de San Martín, Buenos Aires, Argentina;

关键词: bacterial nanotubes;    bioelectrochemical system;    cable bacteria;    geobacter;    multispecies biofilm;    shewanella;   

DOI  :  10.3389/fmicb.2021.726251

来源: DOAJ

【 摘 要 】

Millimeter-length cables of bacteria were discovered growing along a graphite-rod electrode serving as an anode of a microbial electrolysis cell (MEC). The MEC had been inoculated with a culture of Fe-reducing microorganisms enriched from a polluted river sediment (Reconquista river, Argentina) and was operated at laboratory controlled conditions for 18 days at an anode poised potential of 240 mV (vs. Ag/AgCl), followed by 23 days at 480 mV (vs. Ag/AgCl). Anode samples were collected for scanning electron microscopy, phylogenetic and electrochemical analyses. The cables were composed of a succession of bacteria covered by a membranous sheath and were distinct from the known “cable-bacteria” (family Desulfobulbaceae). Apparently, the formation of the cables began with the interaction of the cells via nanotubes mostly located at the cell poles. The cables seemed to be further widened by the fusion between them. 16S rRNA gene sequence analysis confirmed the presence of a microbial community composed of six genera, including Shewanella, a well-characterized electrogenic bacteria. The formation of the cables might be a way of colonizing a polarized surface, as determined by the observation of electrodes extracted at different times of MEC operation. Since the cables of bacteria were distinct from any previously described, the results suggest that bacteria capable of forming cables are more diverse in nature than already thought. This diversity might render different electrical properties that could be exploited for various applications.

【 授权许可】

Unknown