New Synthetic Energy Agenda

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Revision as of 17:53, 14 September 2008

Rebooting Biofuels

“Something I’m really excited about are the synthetic biology projects they’re working on to create new kinds of fuels so we can reduce our dependence on oil and protect our environment.” – Arnold Schwarzenegger, Governor of California.

When genetically modified organisms were first commercialised in the mid 1990s the controversy was largely focused on agriculture and food. A decade later, as fledgling companies seek to move synthetic organisms from lab to marketplace, agriculture is once again on center stage – only this time the spotlight isn’t shining on agri-food, but on agri-energy.

Synthetic biology’s promoters are hoping that the promise of a very “green” techno-fix – synthetic microbes that manufacture biofuels cheaply or put a chill on climate change – will prove so seductive that the technology will win public acceptance despite its risks and dangers.

In his 2006 State of the Union address, US President George W. Bush announced that his government would devote “additional research funds for cutting-edge methods of producing ethanol, not just from corn, but from wood chips and stalks or switchgrass.”

Synthetic biology is one of the “cutting- edge” methods for biofuel production alluded to by President Bush. That part of his speech was written a few days earlier by Aristides Patrinos, then-associate director of the US Department of Energy’s (DOE) Office of Biological and Environmental Research.

At the DOE, Patrinos had overseen both the Human Genome Project and more recently the Genomes to Life (GTL) programme – which supports research to focus synthetic biology on the production of biofuels such as ethanol and hydrogen. The GTL programme also promotes research on technological fixes such as carbon sequestration to mitigate climate change.

Two months after Bush’s speech, Patrinos left the Department of Energy to take up a new post as president of Craig Venter’s new company, Synthetic Genomics, Inc. The company aims to use microbial diversity collected from seawater samples as the raw material to create a new synthetic microbe – one that is engineered to accelerate the conversion of agricultural waste to ethanol.

Patrinos is one of many high-profile industrialists and senior scientists who are climbing aboard the biofuels bandwagon. Bill Gates, for example, the soon-to-be retired chairman of Microsoft, recently bought 25% of Pacific Ethanol, while his Microsoft co-founder Paul Allen has invested in Imperium Renewables, a Seattle-based company that will produce ethanol mainly from soybeans and canola oil. Richard Branson, chairman of the Virgin Group of companies, is devoting $400 million to ethanol investment while Vinod Khosla, co-founder of Sun Microsystems and partner at Kleiner Perkins, a venture capital firm that famously backed AOL, Google and Amazon, now has a string of investments in ethanol companies.(See below.)

The growing enthusiasm for biofuels in the US stems in part from a belated recognition that petroleum supplies in “volatile” parts of the world may not be so easily acquired through trade deals or wars. It also deflects attention from tougher tasks like cutting energy consumption and promoting conservation. The current buzz phrase for ethanol is “energy independence.” A typical articulation comes from a Department of Energy report called From Biomass to Biofuels “A robust fusion of the agricultural, industrial biotechnology, and energy industries can create a new strategic energy independence and climate protection.”

In addition to the energy independence mantra, environmental groups such as Natural Resources Defense Council (NRDC) are championing the development of certain types of ethanol as a climate-friendly fuel that could reduce global emissions of carbon dioxide (CO2).

The US government’s Energy Policy Act of 2005 requires that 4 billion gallons of ethanol per annum be mixed with gasoline at the pumps – that requirement will rise to 7.5 billion gallons by 2012. (A gallon equals 3.79 litres.) Spurred by lavish government subsidies and growing enthusiasm for “energy independence,” over 100 ethanol refineries were operating in the USA as of mid-2006, producing nearly 5 billion gallons of ethanol.

The biofuel buzz is about to become a boom because the US government mandates that at least 30 percent of fuel for transport be derived from biofuels (mostly ethanol) by 2030 – a goal that would require roughly 60 billion gallons of ethanol to be produced per year. Ford, DaimlerChrysler and General Motors together aim to sell over 2 million ethanol-burning cars in the next decade and the world’s largest retailer, Wal-Mart, is mulling plans to sell an ethanol fuel at its 380 US superstores. The ethanol boom is especially good news for giant agro-industrial corporations such as Archer Daniels Midland (ADM), which controls about 30 percent of the US-based ethanol market.

But the surging demand for homegrown biofuels won’t be easily met by current technologies. Fuel ethanol can be produced in two ways: The first is by breaking down agricultural starches into sugar, which is then fermented into ethanol. In Brazil ethanol is processed from sugar cane; in the US the primary feedstock is corn. Growing corn and other food/feed crops for ethanol will divert huge amounts of land, water and energy-intensive inputs away from food production to fuel production. But even then, production levels would fall short of US targets. The US Department of Energy calculates that if all corn now grown in the US were converted to ethanol, it would satisfy only about 15 percent of the country’s current transportation needs. Others put that figure as low as 6 percent. But US corn production is energy intensive, requiring massive inputs of fossil fuels for fertilisers, pesticides, tractors, post-harvest processing and transport ( and corn must be replanted every year unlike sugar cane, which is a perennial crop that produces for 3-6 years before being replanted). In fact, every bushel of corn grown in the US consumes between a third and a half-gallon of gasoline – making it a costly and inefficient feedstock for alternative energy.

A second approach is to produce ethanol from cellulose, the fibrous material found in all plants. Cellulosic ethanol can be made from any leftover plant materials, including woodchips, rice hulls, grasses (such as switchgrass and miscanthus) and straw. There are abundant sources available for cellulosic ethanol, as leaves and stalks – normally considered waste – could become feedstocks.160 Processing ethanol from cellulose has the potential to squeeze at least twice as much fuel from the same area of land as corn ethanol, because much more biomass is available per acre. Miscanthus for example, a perennial grass native to China yields approximately 3,000 gallons of cellulosic ethanol per acre. (One acre is approximately 0.4 hectares.)

If it sounds too good to be true – that’s because it is. It takes a lot of energy to break down cellulose – much more energy, in the form of heat or steam or pressure, than is gained – especially once transport and other lifecycle considerations are factored in. A 2005 study by David Pimentel (Cornell University) and Tad Patzek (University of California Berkeley) examines energy output of biofuels compared with energy input for ethanol production. They found that switchgrass requires 45 percent more fossil energy than the fuel produced, and wood biomass requires 57 percent more fossil energy than the fuel produced. According to Pimentel, “There is just no energy benefit to using plant biomass for liquid fuel. These strategies are not sustainable.”

GMOs haven’t solved the energy equation either. An Ottawa-based company, Iogen, has genetically modified a tropical fungus to produce enzymes that break down cellulose, but it will cost five times more to build its planned biofuel refinery than to build a conventional corn ethanol processing plant. The hunt is on for a better microbe that will cheaply and efficiently break down cellulose to sugars and then ferment those sugars into ethanol – without costing energy. That’s where synthetic biology comes in.

The synthetic biology approach is to custom design a microorganism that can perform multiple tasks, incorporating built-in cellulose-degrading machinery, enzymes that break down glucose, and metabolic pathways that optimise the efficient conversion of cellulosic biomass into biofuel. Aristides Patrinos of Synthetic Genomics describes the all-in-one approach: “The ideal situation would essentially just be one big vat, where in one place you just stick the raw material – it could be switch grass – and out the other end comes fuel….”

Scientists haven’t managed to come up with a designer organism that can do it all, but they are taking steps in that direction. A team from the University of Stellenbosch (South Africa), collaborating with engineering professor Lee Lynd at Dartmouth University (USA), has engineered a yeast that can survive on cellulose alone, breaking down the plant’s cell walls and fermenting the derived sugars into ethanol. Meanwhile, Lynd’s group at Dartmouth is working with a modified bacterium that thrives in high-temperature environments and pro-duces only ethanol in the process of fermentation.168 Lynd hopes to commercialise his technology at a start-up company called Mascoma in Cambridge, Massachusetts (USA). Chairing Mascoma’s board of directors is venture capitalist and ethanol evangelist, Vinod Khosla, who recently snapped up Cargill’s head of biotechnology, Doug Cameron, as his chief scientific advisor. Khosla also funds another synthetic biology energy company known as LS9, based in the San Francisco Bay area (CA, USA).

At Purdue University’s Energy Center, Senior Research Scientist, Dr. Nancy Ho, has developed a modified yeast that can produce 40 percent more ethanol from biomass than naturally occurring yeast, and she is now working with petroleum companies to convert straw into fuel. The Nobel Prize-winning head of the prestigious Lawrence Berkeley Lab, Dr. Steven Chu, grabbed headlines last year when he suggested that synthetic biology could be used to rewire the genetic networks in a cellulose-crunching bug found in the gut of termites. As a first step, the Berkeley Lab is sequencing microorganisms living in the termite’s gut, to identify genes responsible for degrading cellulose.

If any of these synbio approaches is successful, the agricultural landscape could quickly be transformed as farmers plant more switchgrass or miscanthus – not only in North America, but also across the global South. The US DOE considers cellulosic ethanol a “carbon neutral” fuel source (meaning that the amount of CO2 absorbed in growing the plants that produce the biomass roughly equals the amount of CO2 produced in burning the fuel. But these “carbon offset” calculations are controversial because they are difficult, if not impossible, to substantiate). Deeming cellulosic ethanol carbon neutral, however, will likely mean that it will qualify as a Clean Development Mechanism (CDM) activity under the Kyoto Protocol – a scheme established to reward polluting companies with emissions credits if they invest in “clean energy” projects in the global South. Civil society critics regard CDM as industry “greenwashing,” a publicly subsidised scheme that will not combat climate change or diminish its causes. Under the CDM, Northern industries that grow large plantations of energy crops in the South can be allowed to offset these projects against their emissions. Of the 408 registered CDM activities as of mid-November 2006, 55 are described as biomass energy projects. India serves as “host country” for 32 of the 55 projects.

The rush to plant energy crops in the global South threatens to shift marginal land away from food production, a trend that could introduce new monocultures and compromise food sovereignty. At SynBio 2.0, the May 2006 conference held at Berkeley, Dr. Steven Chu noted that there is “quite a bit” of arable land suitable for rain-fed energy crops, and that Latin America and Sub-Saharan Africa are areas best suited for biomass generation. The 2005 US Energy Act mandates the US State Department to transfer climate-friendly technologies (“greenhouse gas intensity reducing technologies”) to developing countries, a move that could increase pressure on already scarce or depleted soil and water resources if it involves large-scale production of energy crops. A 2006 report by the Sri Lanka-based International Water Management Institute (IWMI) warns that growing crops for biofuel could worsen water shortages: “If people are growing biofuels and food it will put another new stress. This leads us to a picture of a lot more water use,” explained David Molden of IWMI. By removing biomass that might previously have been returned to the soil, fertility and soil structure would also be compromised. As presently envisioned, large-scale, export-oriented biofuel production in the global South will have negative impacts on soil, water, biodiversity, land tenure and the livelihoods of peasant farmers and indigenous peoples.

Growing demand for energy, and the shift from food to fuel production, could increase the energy sector’s influence in agricultural policies. It could also mean a new wave of consolidation in the form of mergers and strategic alliances between agribusiness and energy corporations. The Department of Energy’s roadmap for developing synthetic biology technologies for ethanol production notes: “This research approach will encourage the critical fusion of the agriculture, industrial biotechnology, and energy sectors.” In a recent press release on its biofuels strategy, ADM’s CEO Patricia Woertz claims that her company is “uniquely positioned at the intersection of the world’s increasing demands for both food and fuel. As one of the largest agricultural processors in the world and the largest biofuels producer in the world, ADM is in a category of one to capitalize on the exceptional opportunity ahead.”

But converting plant biomass to fuel isn’t the only way that synbio could upend the energy sector. Craig Venter’s 2-year microbe-collecting expedition netted previously unknown species of bacteria that capture sunlight with photoreceptors and convert it into chemical energy. Since photosynthesis is capable of producing minute levels of hydrogen, Venter’s team is exploring the idea of altering photosynthesis in cells to produce hydrogen.

University of California professor Jay Keasling, founder of Amyris Biotechnologies, wants to design an organism that produces a fuel similar to gasoline. “Ethanol has a place, but it’s probably not the best fuel in the long term,” Keasling told Technology Review. “People have been using it for a long time to make wine and beer. But there’s no reason we have to settle for a 5,000-year-old fuel.” Amyris recently hired John Melo, former president of US Fuels Operations for BP, as its new chief executive. “It even sounds amazing to us what we are trying to do,” said Jack Newman, a co-founder of Amyris and vice president of research. “Basically, we are taking the modern principles of synthetic biology and trying to replace crude oil.”

The US military also wants to use synthetic biology for energy production. The US government’s Defense Advanced Research Projects Agency (DARPA) is funding a collaboration between Richard Gross of Polytechnic University (New York) and gene synthesis company DNA 2.0 (Silicon Valley, California) to develop a new kind of energy-rich plastic that can be used first for packaging and then reused as fuel. DNA 2.0 aims to synthetically design the enzymes to produce the polymer. The company claims that soldiers in the field will be able to burn the plastic that wraps their supplies, recovering 90% of the energy as electricity.