The discovery of deep-sea hydrothermal vents caused scientists to reconsider their notions about life in the deep sea. In these seemingly inhospitable environments, free-living microbes, as well as microbial-animal symbioses, thrive in the warm waters around vents. The biomass per unit area in this environment is comparable to that of rainforests. Uniquely, these highly productive ecosystems are based on microbial chemoautotrophic metabolism, wherein microbes generate metabolic energy by drawing oxygen or nitrate from surrounding seawater to oxidize reduced chemicals (e.g., sulfide) found in the vent fluids (Sievert and Vetriani, 2012, in this issue). The rapid and voluminous fluid flux through hydrothermal vents replenishes these substrates at a rate sufficient to support this substantial community. The tremendous microbial productivity observed at vents raises the question as to whether these microorganisms are also well suited for bioenergy and biofuel production. Here, we discuss the utility and issues associated with two example approaches: in situ bioelectricity generation and microbially mediated large-scale biofuel production.

Girguis, P.R., and J.F. Holden. 2012. On the potential for bioenergy and biofuels from hydrothermal vent microbes. Oceanography 25(1):213–217, https://doi.org/10.5670/oceanog.2012.20.

Chou, C.J., F.E. Jenney Jr., M.W.W. Adams, and R.M. Kelly. 2008. Hydrogenesis in hyperthermophilic microorganisms: Implications for biofuels. Metabolic Engineering 10:394–404, https://doi.org/10.1016/j.ymben.2008.06.007.

Dewan, A., H. Beyenal, and Z. Lewandowski. 2008. Scaling up microbial fuel cells. Environmental Science and Technology 42:7,643–7,648, https://doi.org/10.1021/es800775d.

Fiala, G., and K.O. Stetter. 1986. Pyrococcus furiosus sp. nov. represents a novel genus of marine heterotrophic archaebacteria growing optimally at 100°C. Archives of Microbiology 145:56–61, https://doi.org/10.1007/BF00413027.

Franks, A.E., and K.P. Nevin. 2010. Microbial fuel cells, a current review. Energies 3:899–919, https://doi.org/10.3390/en3050899.

Girguis, P.R., M.E. Nielsen, and C.E. Reimers. 2009. Fundamentals of sediment-hosted microbial fuel cells. Pp. 327–345 in Bioelectrochemical Systems, First Edition. K. Raebey, ed, IWA publishing, London.

Gong, Y., S.E. Radachowsky, M. Wolf, M.E. Nielsen, P.R. Girguis, and C.E. Reimers. 2011. Benthic microbial fuel cell as direct power source for an acoustic modem and seawater oxygen/temperature sensor system. Environmental Science and Technology 45:5,047–5,053, https://doi.org/10.1021/es104383q.

Lovley, D.R. 2010. Powering microbes with electricity: Direct electron transfer from electrodes to microbes. Environmental Microbiology Reports 3:27–35, https://doi.org/10.1111/j.1758-2229.2010.00211.x.

Lovley, D.R., and E.J.P. Phillips. 1988. Novel mode of microbial energy metabolism: Organic-carbon oxidation coupled to dissimilatory reduction of iron or manganese. Applied and Environmental Microbiology 54:1,472–1,480.

Nielsen, M.E., C.E. Reimers, H.K. White, S. Sharma, and P.R. Girguis. 2008. Sustainable energy from deep ocean cold seeps. Energy and Environmental Science 1:584–593, https://doi.org/10.1039/B811899J.

Oslowski, D.M., J.H. Jung, D.H. Seo, C.S. Park, and J.F. Holden. 2011. Production of hydrogen from α-1,4- and β-1,4-linked saccharides by marine hyperthermophilic archaea. Applied and Environmental Microbiology 77:3,169–3,173, https://doi.org/10.1128/AEM.01366-10.

Potter, M.C. 1911. Electrical effects accompanying the decomposition of organic compounds. Proceedings of the Royal Society B 84:260–276, https://doi.org/10.1098/rspb.1915.0030.

Rabaey, K., and R.A. Rozendal. 2011. Microbial electrosynthesis—Revisiting the electrical route for microbial production. Nature Reviews Microbiology 8:706–716, https://doi.org/10.1038/nrmicro2422.

Reimers, C.E., P.R. Girguis, H.A. Stecher III, L.M. Tender, N. Ryckelynck, and P. Whaling. 2006. Microbial fuel cell energy from an ocean cold seep. Geobiology 4:123–136, https://doi.org/10.1111/j.1472-4669.2006.00071.x.

Singh, A., D. Pant, N.E. Korres, A.-S. Nizami, S. Prasad, and J.D. Murphy. 2010. Key issues in life cycle assessment of ethanol production from lignocellulosic biomass: Challenges and perspectives. Bioresource Technology 101(3):5,003–5,012.

Sievert, S.M., and C. Vetriani. 2012. Chemoautotrophy at deep-sea vents: Past, present, and future. Oceanography 25(1):218–233, https://doi.org/10.5670/oceanog.2012.21.

Tijhuis, L., M.C.M. van Loosdrecht, and J.J. Heijnen. 1993. A thermodynamically based correlation for maintenance Gibbs energy requirements in aerobic and anaerobic chemotrophic growth. Biotechnology and Bioengineering 42:509–519, https://doi.org/10.1002/bit.260420415.

White, H.K., C.E. Reimers, E.E. Cordes, G.F. Dilly, and P.R. Girguis. 2009. Quantitative population dynamics of microbial communities in plankton-fed microbial fuel cells: Examining the relationship between power production, geochemistry and microbial ecology. The ISME Journal 3:635–646, https://doi.org/10.1038/ismej.2009.12.

This is an open access article made available under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/), which permits use, sharing, adaptation, distribution, and reproduction in any medium or format as long as users cite the materials appropriately, provide a link to the Creative Commons license, and indicate the changes that were made to the original content. Images, animations, videos, or other third-party material used in articles are included in the Creative Commons license unless indicated otherwise in a credit line to the material. If the material is not included in the article’s Creative Commons license, users will need to obtain permission directly from the license holder to reproduce the material.