Long-distance electron transfer in a filamentous Gram-positive bacterium

• Published in: Nature communications Vol. 12; no. 1; pp. 1709 - 9
• Main Authors: Yang, Yonggang, Wang, Zegao, Gan, Cuifen, Klausen, Lasse Hyldgaard, Bonné, Robin, Kong, Guannan, Luo, Dizhou, Meert, Mathijs, Zhu, Chunjie, Sun, Guoping, Guo, Jun, Ma, Yuxin, Bjerg, Jesper Tataru, Manca, Jean, Xu, Meiying, Nielsen, Lars Peter, Dong, Mingdong
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 17.03.2021; Nature Publishing Group UK; Nature Portfolio
• Subjects: Appendages; Atomic force microscopy; Bacillaceae - cytology; Bacillaceae - growth & development; Bacillaceae - metabolism; Bacteria; Biochemical fuel cells; Bioelectric Energy Sources - microbiology; Cell envelopes; Cellular communication; Electric Conductivity; Electrodes - microbiology; Electron transfer; Electron Transport - physiology; Electrons; Fimbriae, Bacterial - metabolism; Fimbriae, Bacterial - ultrastructure; Fuel technology; Gram-negative bacteria; Gram-Positive Bacteria - cytology; Gram-Positive Bacteria - growth & development; Gram-Positive Bacteria - metabolism; Graphite; Microelectrodes; Microorganisms; Microscopy, Atomic Force; Nanowires; Pili; Proteins
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-21709-z

Long-distance extracellular electron transfer has been observed in Gram-negative bacteria and plays roles in both natural and engineering processes. The electron transfer can be mediated by conductive protein appendages (in short unicellular bacteria such as Geobacter species) or by conductive cell envelopes (in filamentous multicellular cable bacteria). Here we show that Lysinibacillus varians GY32, a filamentous unicellular Gram-positive bacterium, is capable of bidirectional extracellular electron transfer. In microbial fuel cells, L. varians can form centimetre-range conductive cellular networks and, when grown on graphite electrodes, the cells can reach a remarkable length of 1.08 mm. Atomic force microscopy and microelectrode analyses suggest that the conductivity is linked to pili-like protein appendages. Our results show that long-distance electron transfer is not limited to Gram-negative bacteria.