Research Overview

In collaboration with Chappell Lab (University of Kentucky, Plant & Soil Sciences) and Bruce Logan (PSU, Civil & Environmental Engineering), CurtisLab successfully completed a 4-year research grant (2010-2014) under the aggressive milestone-driven ARPA-E electrofuels initiative to generate a smart energy infrastructure that would provide energy while minimizing the environmental impact of using fossil fuels. Specifically, CurtisLab focused on a means of converting diffuse solar energy into energy-dense transportation fuels. Our holistic approach encompassed leveraging new tools of ‘synthetic biology’, whereby genes from one organism are fabricated into another, in tandem with engineering bioreactor systems, focusing not only on functionality but on the economic feasibility necessary to compete with foreign fossil fuel pricing.

The diagram to the left demonstrates the overall ARPA-E concept in which (1) we metabolically engineered Rhodobacter, which inherently consumes electrons, via synthetic biology with the genes to produce botryococcene, an energetically-dense hydrocarbon, and (2) interfaced botryococcene production to photovoltaics (P.V.) and microbial fuel cells to emphasize economic feasibility via solar energy capture.

Bacteria which inherently 'consumes' electrons, were engineered with the Chappell Lab's genes isolated from oil-rich Botryococcus braunii Race B for a hydrocarbon, specifically botryococcene, production. Thus, this bypassed the inefficiency of photosynthesis in plants, instead leveraging (free) solar energy to sequester carbon in a liquid (thereby portable and stable) fuel via feeding of either hydrogen (produced from splitting water with electricity) or electrons directly to 'power' a microorganism that is genetically engineered to produce hydrocarbons.

Implicit to this upstream metabolic engineering is a focus downstream on low-cost reactor design. To that end, a process economic assessment evaluated the two functionally-engineered bacterial chemoautotrophic organisms, including the proposed Rhodobacter capsulatus as well as Ralstonia eutropha, pointing towards the numerous remaining obstacles in achieving biofuels feasibility.

Similarly, CurtisLab's review of Metabolic Engineering to date revealed a staggering order of magnitude difference (see graph to LEFT) between native and engineered productivities, despite decades of global research and investment. This points to a vast need towards a better-informed, more holistic approach towards sustainable energy independence and is the subject of CurtisLab's ongoing work.

Papers, presentations, and patents

Nybo, SE, Khan, N, Woolston, BM, Curtis, WR. (2015) Metabolic engineering in chemolothoautotrophic hosts for the production of fuels and chemicals. Metab. Eng. DOI: 10.1016/j.ymben.2015.04.008. [Epub ahead of print]

Khan, Nymul. Nybo, Eric S., Chappell, Joe, Curtis, Wayne R. (2015) Triterpene hydrocarbon production engineered into a metabolically versatile host - Rhodobacter capsulatus. Biotechnology & Bioengineering. DOI: 10.1002/bit.25573. [Epub ahead of print]

Khan NE, Myers JA, Amalie L. Tuerk AL, Curtis WR (2014) A process economic assessment of hydrocarbon biofuels production using chemoautotrophic organisms, Bioresource Technology, 172:201–211, 2014. DOI: 10.1016/j.biortech.2014.08.118.

Curtis WR, Chappell J. Rhodobacter as a Microbial Platform for Algae Hydrocarbon Electrofuels Production. 2012 ARPA-e Energy Innovation Summit: Washington D.C. February 27-29, 2012. (FOLLOW THIS LINK for presented poster, handouts on various technology developments, and videos of the demonstrations presented at the summit technology showcase).

Curtis, W.R., Growing cells in a reservoir formed of a flexible sterile plastic liner, U.S. Patent # 6,709,862, March 23, 2004.

Curtis, W.R., Method and apparatus for aseptic growth or processing of biomass, U.S. Patent # 6,245,555, June 12, 2001.


Khan, Nymul. Development of biological platform for the autotrophic products of biofuels. Dissertation, Ph.D. The Pennsylvania State University: University Park, PA (2015).


ARPA-e Electrofuels: See here for a more comprehensive look at our ARPA-e Electrofuels Project and its deliverables.

Meet the Electrofuels Team

Curtis Lab Researchers

  • Alex Rajangam (post-doc)

  • Mustafa Erbakan (graduate)

  • Nymul Khan (graduate)

  • Tim Miskimmin (graduate)

  • John Myers (graduate)

  • Amalie Tuerk (graduate)

  • Erik Wolcott (graduate)

  • Serena X (graduate)

  • Brandon Curtis (pre-doc)

  • Ben Woolston (pre-doc)

  • Andrew Barmasse (undergrad)

  • Anurag Sen (undergrad)

  • Reed Taylor (undergrad)

  • Stephanie Tran (undergrad)

Chappell Lab (Plant & Soil Science, UKy)

  • Eric Nybo (post-doc)

  • Scott Kinison (technician)

Logan Lab (Civil & Environmental Engineering, UKy)

  • John Piscotta (post-doc)

Winograd Lab Researchers

  • Lauren Jackson (graduate)