The ARPA-E: Renewable Fuel through Genetic Modification, photosynthesis, and the Electro Fuels Program

The technology needed to create renewable fuel and the solutions to problems like global contaminated drinking water and starvation exist in hundreds of labs around the world.  For example, the Slingshot, a small water purification unit developed by Dean Kamen, runs on cow dung, requires no filters, produces potable water, and can simultaneously power 70 energy efficient light bulbs.  Globally, we produce 150% of the amount of food required to feed everyone, yet we cannot manage to transport it and millions die of starvation every year; small changes in world-wide food distribution and transportation, accomplished through improved international communication, would be a strong step towards ending hunger.  And people are coming up with new sources of renewable energy, and more efficient ways to extract that energy, on a daily basis.  Unfortunately the economic incentive for wide-scale use of expensive inventions usually just isn’t there, and without incentive our progress will always be stunted.  Still, in 2007 the U.S. Department of Energy saw fit to commission a new branch of research known as the Advanced Research Project Agency – Energy.  Its goal has been to investigate and fund cutting edge research into energy technologies and began with a budget of $400 million.  Much of the work they fund is kept under wraps, but Richard Blaustein had the opportunity to review a few projects that will be discussed below.  From genetically modifying plants to electro-stimulating specific microorganisms, the scientists working for the ARPA-E are searching for essentially new sources of renewable energy.  And so far, they have enjoyed a great deal of success.—Edward McLean
            Blaustein, Richard. 2012 Can Biology Transform Our Energy Future?: ARPA-E infuses innovative research ventures with fresh funds. Journal of BioScience, Vol. 62, No. 2.

            While much of their funding is spent on improving existing technologies, the ARPA-E has taken special interest in developing biotechnology that utilizes existing biological processes.  Through genetic modification, several projects focus on using target organisms to produce renewable fuel naturally.  This article focused on two different pursuits, but each requires diligent research across many fields.  The first is genetically modifying plants so that they can photosynthesize more efficiently and produce more oil that can be refined from the plant matter, and used as biofuels.  This project is known as Plants Engineered to Replace Oil (PETRO), and from its outset, its mission has been to “get photosynthesis to produce biofuels directly that provide more of what we need and to use the existing energy-capture process to put more energy into fuel” (116).  Many of the plants that produce biofuels do so indirectly; only after distillation or some other secondary process can their products be made into fuels.  Researchers at PETRO are exploring ways to tweak photosynthesis and other metabolic pathways that will take in sunlight and CO2 and yield a directly usable fuel, stored throughout the plant body.  In processes that produce fuel from crops like maize or sugar cane, the usable product only comes from one part of the plant and the rest is discarded.  If target plants were modified so that their stems and leaves could also be used to supply fuel, the entire process would be enormously more efficient.  The environmental impact of creating fuel this way is meniscal next to the imprint left by searching for and burning fossil fuels, and it is renewable so long as sunlight is available.  PETRO has provided a number of promising breakthroughs that demonstrate considerable hope for the future of renewable energy.  This team now faces the daunting task of supplying incentive to policy makers to adopt and fund this research.  If only that was as doable as producing renewable energy by modifying photosynthesis. 
The second project this article discussed at length is the Electro Fuels Project, which involves essentially engineering the genome of a microorganism and implanting that code into a target E. coli cell.  This engineered genome borrows genes from different microbes—sometimes from as many as 16 different organisms—that code for specific enzymes involved in pathways used to fix CO2 into higher carbon compounds.  Through these modified pathways, much like in the aforementioned photosynthesis example, the E. coli cells will take atmospheric CO2 and transform it into a fuel such as butanol, which is “a high energy carbon-compound,” which would be excreted and easily collected.  This process is known as Electro Fuels because the catalyst that begins the carbon fixation process is an electrical shock, administered by a tiny cathode.  A remarkable branch of their research extends into adapted evolution studies; this type of investigation “instigates and processes mutations and changes for the whole organism.”  In other words, these scientists expose the target organism to a new stimulus, and perhaps the genetic material the bacterium will require to adapt, and do so for generation after generation until the organism possesses the biological machinery to coexist with—maybe even utilize—the introduced stimulus.  In this case that would involve mass producing the colonies of bacteria that are able to process carbon using the newly discovered pathways and identifying the genes that code for the enzymes that allow them to make higher energy carbon compounds as a by product of respiration.  The next step would be removing the target gene, along with up 20 others involved in some other piece of the operation, combining them and correctly inserting them into the malleable E. coli.  The whole procedure sounds maddening and meticulous, but with careful research the project shows remarkable promise.
            Another Electro Fuels project was discussed and it too pertains to the fixation of carbon, but on a much larger scale and smaller focus on creating renewable energy.  The group involved in this research has its sights set on carbonic anhydrases, which are naturally occurring enzymes that capture carbon, sometimes at astonishing rates.  The team reports that one carbonic anhydrase molecule can fix one million CO2 molecules every second, adding that they are among the fastest working enzymes in nature.  They have recently been working on another directed-evolution study to make the enzyme more adapted to the “extreme alkaline and thermal conditions found in emission-capture systems.”  The work is less predicable than the researchers might want, but they cannot complain too much, as they have seen a million-fold increase in their carbonic anhydrase’s stability.  If these enzymes were technologically manipulated and available for widespread use in emission-capture systems installed by factories, the CO2 emissions across the country would rapidly decrease. 
The cutting edge research discussed in this brief review pertains directly to bioremediation, but on a much larger scale than the focus of most remediating projects.  The ARPA-E is actively searching for ways to use the excess CO2 our industrial pursuits have generated to create fuel, fundamentally reversing the production of energy and using the largest source of pollution and existing biological systems to make energy.  We are in a noble age of technological advances and have never been better suited to subdue some of the many issues that plague our world.  But we also have never existed in a world with more opposition, with more of a need for an individual to blame, and with more “extreme economics” (from sociobiologist Rebecca Costa), all three of which are biologically engrained in each of us and stand like unconquerable mountains in the way of progress.  We need to overcome a lot more than the energy crisis if we wish to save ourselves, and I guarantee prevailing over our own hardwiring will be unfathomably more difficult compared to making renewable energy, which has already been done.

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