The Other Ethanol

(Graphic: NCGA)

For decades, genetic engineering has been focused on changing the structure of plants to improve specific traits such as taste, color, quality, shelf life, drought tolerance, resistance to insects or disease, weed control and faster growth in colder climates. Today, seed and biotechnology companies are working together - in a field called bioenergy - to tailor crops that are more suited for biofuels, rather than traditional food production. 

But where should the line be drawn?

One example is Syngenta Seed Inc.'s plan to add an enzyme to corn seed to reduce the amount of lignin, a substance that gives plant stalks the stiffness to stand upright but interferes with turning a plant's cellulose into ethanol, leading to higher refinery costs.  While some companies see using genetic engineering of corn as promising, others are concerned, not wanting to mess with the nation's food supply. Monsanto Co., for instance, says it will continue to focus its efforts in biofuel development via conventional breeding, which the company says is quicker. E.I. DuPont De Nemours & Co., through its Pioneer subsidiary, is following suit.  Both Monsanto and DuPont have already developed corn hybrids that offer more ethanol output per bushel. For example, certain corn varieties have higher fermentable starch content, which can increase ethanol production between 2 and 5 percent over other varieties. Monsanto recently entered into a joint venture with Sandia National Laboratories to further research into biofuels. It also said that ethanol factories are now starting to request or pay a premium for these more-productive varieties.  DuPont, in one of its initiatives, has partnered with the U.S. Department of Energy (DOE) and others to develop an integrated corn-based biorefinery that can utilize the entire corn plant - grain, leaves and stalk. If genetic engineering can and has been used to enhance appearance, taste or some other attribute for consumers, proponents say, "Why not for fuel?" Experts say that for biofuels to truly reduce dependence on foreign oil, biocrops must be designed to yield more energy per acre - a concept known as yield density.  The NY Times cited a DOE report that states "even if the nation's entire corn crop were converted to ethanol production, it would replace only about 15 percent of petroleum use."  In the article, DOE biofuel expert Gerald A. Tuskan said, "Half the improvement we make over the next 10 to 15 years will come from improving the feedstocks."  Protecting the food chain The rush to corn-based biofuels has its critics, of course. From public safety to sustainability, a number of issues have been raised that the industry and government agencies need to address. Margaret Mellon, of the Union of Concerned Scientists, expresses concern that crops with added, but untested enzymes might cross-pollinate with natural plants in nearby fields. Without the long-term effects of such enzymes being known, she maintains, there is a risk to the food supply. Bill Freese of the Center for Food Safety also holds concerns about the lack of knowledge regarding the use of certain enzymes in genetic engineering. He notes that certain enzymes have already been shown to induce allergies. In the case on Syngenta's softer lignin-producing enzyme, the company has applied for certification as being safe for human consumption, which is currently being reviewed by the U.S. Department of Agriculture. DuPont's William S. Niebur points out that the demand for corn is so dramatic, it has the potential to change some sound farming practices in the agricultural community, where many farmers are already struggling for sustained adequate income. Under the economic pressure to grow corn year after year, he says, crop rotation and other sound farming practices could be compromised in the gold rush to corn, which could strain the soil's fertility and allow the build-up of insects and disease.

(Graphic: NCGA) The National Corn Growers Association (NCGA) countered critics by stating, "The ethanol process removes and uses only the starch portion of the kernel. The protein, which is left intact by the ethanol process, is a highly valued product in food and feed markets." The NGCA also noted that only 9.2 percent of the nation's total 13.2 billion bushels is used in the food industry, the majority of it as a sweetener. Contrary to popular misconception, the organization said that over the last 15 years, prices paid for corn have fallen, even as ethanol production has ramped up. The NCGA also maintains that its farmers could supply 10 percent of America's energy needs by 2016, without jeopardizing other markets for corn. Plants on steroids? Most of today's ethanol comes from starches and sucrose contained in the kernels of plants such as corn. Yet the bulk of a plant's carbohydrates - in the form of cellulose - are contained in the leaves, stems and stalks of plants.  In addition, cellulose isn't restricted to just grasses and smaller plants. Trees such as the abundant poplar variety provide another viable feedstock. For those on the cutting edge, enabling access to this potential in an efficient and timely manner is at the heart of the promise and potential of cellulose-based ethanol. 

(Graphic: DuPont) In an effort to expand the supply stock for biofuels, many experts say, corn isn't enough. Current research is examining sources of cellulose fiber, particularly in switchgrass, poplar, wood chips and others. Plants specifically designed for energy production offer several advantages: * They aren't part of the traditional food supply chain.  * They require less energy to produce than corn.  * They can be grown abundantly in less-tolerant environments, requiring less irrigation and fertilization.  * Unlike corn, sustainability and crop rotation aren't issues.  * The ethanol yield of cellulose sources is higher than corn.

Miscanthus grass
(Photo: Mendel Biotechnology Inc.) Ceres is one of several companies on this new leading edge towards biofuels, and it is concentrating on switchgrass. As a supplier of genetics technology to Monsanto, its greenhouses contain versions of switchgrass that have been bred conventionally, as well as some that have been engineered to provide higher yields per acre or break down into ethanol more readily.  Ceres CEO Richard W. Hamilton cites examples of switchgrass varieties that are now yielding 8 to 9 tons of biomass per acre, a better than 60 percent improvement compared to conventional switchgrass yields of five tons per acre.  Doing the MathYield density (YD), expressed in tons of biomass per acre, is a key number in ethanol development. The location and number of ethanol refineries is directly impacted by YD. Because of the high costs of shipping biomass, refineries have to be located closer to where the crops are grown - unlike oil refineries, which can rely on pipeline transport of raw goods. A low YD can make the location of a plant impossible, whereas a high YD can enable a viable, large investment.

According to Ceres and other companies, research indicates that genomics applied to cellulose feedstocks can increase YD by up to 300 percent and more, from the current 5 tons per acre to between 15 and 20 tons per acre. In addition, the higher YD reduces the radius of cropland needed for a cellulose biorefinery to be viable by 90 percent.

Consider these scenarios:
* Currently, a YD of 5 tons/acre is sustainable. Typically, 80 gallons of ethanol can be produced per ton of biomass. Thus, one acre can yield 400 gallons of ethanol (80 X 5).

* Genetically altered plants can have triple the YD. In our example, 15 tons/acre, each producing 80 gallons of ethanol per ton, would result in 1,200 gallons of ethanol (80 X 15).

* Factor in improvements in extraction technology that could increase the current 80 gallons/ton, as well as overall ethanol production.

Bottom line: More biorefineries and more ethanol in America.(Source: Ceres) When interviewed by the NY Times, he said, "You could turn Oklahoma into an OPEC member by converting all its farmland to switch grass. Switchgrass is the energy crop that melts in your mouth, if you will." In the article, Hamilton said that on a per-acre basis, there is far more cellulose grown than starch or sucrose - enough, in fact, to provide America with more than 100 billion gallons per year once developed.  Oklahoma, for example, has 34 million acres of farmland. If it were all planted in corn, the ethanol produced at current yields of 400 gallons per acre would surpass all the oil imported from Iraq. If the yield density could be improved to the levels that several companies are headed toward, more than 43 billion gallons of ethanol could be produced in Oklahoma alone. That is more than the United States imports from Iran today. In fact, it would place Oklahoma among the Top Three OPEC producers.  Designing biocrops for fuel DuPont recently made a major breakthrough by genetically modifying an ethanol-producing bacterium known as Zymomonas mobilis. It is efficient at eating the glucose sugar found in the corn kernel as well as the xylose sugar locked away in cellulose. Both are crystalline structures difficult to break apart, in particular the latter. But cellulose ethanol research like this takes funding and time.  John Ranieri, a DuPont vice president, stated in a Wall Street Journal article, "Even though DuPont has deep pockets for experimental work, spending $1.3 billion annually on research and development, the difficulty of turning biomass into fuel makes it such a risky venture that DuPont probably wouldn't attempt it without government backing." In California, Mendel Biotechnology Inc. is researching another cellulose source, Miscanthus, a perennial grass native to China. CEO Chris Somerville - who is also a Stanford University professor and the director of plant biology at the Carnegie Institution - said Miscanthus could produce more than 20 tons of biomass per acre each year, with several advantages over other alternatives.  "No planting, no fertilizing, no irrigation," he said. "You can just cut it every year for 10 years."