‘Superbug’ Gobbles Waste to Make Cheap, Clean Fuel : Energy: Scientist splices genes to create bacterium that converts most plant material into pollution-free ethanol.
In the beginning, Lonnie Ingram’s objective was to get to the bottom of the way bacteria make alcohol--particularly in tequila.
In the end, the University of Florida microbiologist wound up discovering something with potentially profound economic and environmental implications.
Ingram took two genes from one strain of bacteria, transferred them into another and came up with a hybrid microbe he affectionately calls his “superbug.”
It is an apt name. Ingram’s superbug, it turns out, is a ravenous bacterium that has the ability to produce ethanol from nearly any kind of plant material: cornstalks, corncobs, sawdust, grass clippings, old newspapers and even the sludge generated by paper mills.
Ingram’s associates believe the superbug may make it possible to distill pure ethanol from a variety of waste materials for as little as 45 to 50 cents per gallon, a development that could make it a rival to gasoline and create a huge alternative fuel industry around the world. Ingram’s discovery could create a windfall for his university as well, but his colleagues are not alone in their assessment of the superbug as something special.
In March, 1991, more than two centuries after Samuel Hopkins received the first American patent for a process used to make potash, the University of Florida was awarded U.S. Patent No. 5,000,000 for the marvelous microbe that Ingram created in the laboratories of its Institute of Food and Agricultural Sciences.
Then-Commerce Secretary Robert A. Mosbacher made the presentation on behalf of the U.S. Patent and Trademark Office, calling the achievement testament to “the increasingly rapid rate at which technology is advancing in the United States and around the world.”
A total of 121 years passed between the issuance of Sam Hopkins’ potash patent and Patent No. 1,000,000, which was awarded to the inventor of a solid automobile tire. But it took only 15 years to progress from Patent No. 4,000,000, awarded for a recycling system for asphalt aggregates used in road paving, to No. 5,000,000 for Ingram’s custom-tailored microbe.
Ingram predicts that more man-made bugs like his own will be coming along soon to perform yeoman environmental service at chores such as production of petroleum-based chemicals and specially designed products.
The first glowing predictions for his superbug, including the projected launching of an initial commercial operation in 1992, proved excessively optimistic. But a technology built around the superbug is now being scaled up to commercial size.
Ingram developed his bug by taking two genes from one strain of bacteria, called z mobilis , whose chief service had been to create tequila, and transferring them into e coli , a form of bacteria found in the intestines of all warm-blooded animals.
The hybrid microbe that resulted will first be used commercially in a New York plant that is expected to produce 10 million gallons of ethanol fuel per year from the sludge generated by 15 Upstate paper mills.
Also in the works is a smaller operation in Brazil, where about 80% of the automobiles operate on pure ethanol. There, the fuel is extracted from sugar cane, and the planned superbug plant would produce 4 million gallons per year from the chopped-up stalks left by sugar mill operations.
Bionol Corp., a Massachusetts firm that will operate the New York plant, and BioEnergy International, a Gainesville, Fla., company holding exclusive license to the university’s patent, say they plan to develop 100 million gallons of annual ethanol production capacity based on the superbug. BioEnergy is a subsidiary of Quadrex Corp., a Campbell, Calif., nuclear engineering firm that diversified its interests after the Three Mile Island accident and has since moved its headquarters to Gainesville.
Although ethanol promoters have long touted the alcohol extracted from corn as a potential answer to environmental prayers and the best way to reduce U.S. reliance on imported oil, it remains intensely controversial.
As a fuel additive, ethanol boosts the octane rating of gasoline. During winter months when carbon monoxide pollution is worst, ethanol is now used in 39 cities to increase the oxygen content of gasoline, as required by the Clean Air Act.
As a pure fuel, ethanol does indeed burn cleanly. But when it is blended with gasoline, it increases volatility and causes increased evaporation of smog-causing chemicals. For that reason, many critics have written off gasohol as a major alternative fuel in the nation’s smog-prone urban areas.
Environmentalists also contend that ethanol would be prohibitively expensive in the absence of government subsidies. Under current law, ethanol enjoys a 5.4 cents-per-gallon exemption from the gasoline excise tax when it is used in a blend.
But the drawbacks would largely evaporate if the price were halved and sufficient supplies became available to enable U.S. vehicles to burn pure ethanol, said David Doninger, an attorney for the Natural Resources Defense Council and a longtime ethanol critic.
The environmental debate aside, the emergence of technology for widespread conversion of waste into ethanol may lead to serious competition in an industry now dominated by giant Archer Daniels Midland Co. of Decatur, Ill. ADM makes more than two-thirds of the 1 billion gallons of ethanol now produced in the United States each year.
David Fowler, BioEnergy’s founder and managing director, noted during the patent presentation that a key source of feedstock for the superbug facilities will be cornstalks and cobs that now go to waste. “By the time our process is in full implementation,” he said, “the rest of the world will be using our corn and wheat for food, not alcohol.”
Before he created his superbug, Ingram spent years doing basic research on alcohol-producing bacteria. Eventually, he recognized that genetic engineering might provide the answer to a challenge that has intrigued microbiologists for more than two decades.
Ethanol is produced by fermenting the sugars contained in grains and other organic materials. But some complex sugars, such as those derived from the cellulose in cornstalks, are unaffected by the yeasts and other organisms normally used in the fermentation process.
“The issue in making alcohol from non-edible biomass is how easily you can convert molecules of cellulose back into the original sugars from which they were made,” Fowler said. “Once you get them there, you can ferment them. All those sugars are not fermentable from normal means such as yeast. So even if you could convert them all back to sugar, about a third of them would just stay there. There are the hemicellulose-derived sugars; yeast just looks at them and ignores them.”
Ingram began to investigate the problem, aided by colleagues Flavio Alterthum and Tyrrell Conway. They soon realized that “there was almost no one around working in the biomass area,” Ingram said. “It was just too good to be true.
As it happened, Australian and German teams were trying to engineer an organism that could transform biomass into alcohol. Ingram was unaware of their work, but they had learned what he was doing because a research proposal he had submitted to the U.S. Department of Energy had been circulated for review in the scientific community.
But Ingram’s group was first to reach the critical conclusion that two genes, not one, had to be transplanted to create a microbe that could successfully make alcohol out of waste.
Since Ingram applied for his superbug patent, narrowly beating out the Australian and German scientists, he has continued improving his hybrid microbe, principally causing it to speed its growth and increase its fermentation efficiency.
“What we have done in our process is to come up with a way of biologically taking the cellulose and hemicellulose and breaking it down into individual sugars,” said Fowler, the BioEnergy official. “And we have an organism that will ferment any sugar, no matter where it comes from, directly into alcohol.” The operation is very nearly a closed-loop system.
Enzymes break down the waste feedstock into sugars that are fermented by the genetically engineered bacterium. The process produces both ethanol and carbon dioxide--the latter can be sold for uses such as carbonation of soft drinks and for use in fire extinguishers.
All that is left of the original material is lignin, nature’s “glue” that binds and supports cellulose fibers in organic materials and is the substance that gives off most of the heat when wood is burned. Collected and dried, the lignin becomes fuel for the boilers powering the plant.
In the end, the only waste product is ash, and in the case of plants fed by paper mill sludge, a clay residue from paper production.
Although this residue would amount to thousands of tons per year, one of the foremost appeals of the waste-to-ethanol technology is that in some instances it could help resolve the crisis of overflowing landfills.
It was the combination of overwhelmed landfills and more strict Environmental Protection Agency regulations that made Glen Falls, N.Y., a likely site for the first plant to convert paper mill sludge to ethanol.
Construction of the $25-million facility is to start in late spring, and operations are to begin in mid-1994.
Jeff Gatto, vice president for operations at Bionol Corp., said an announcement will soon be forthcoming of a long-term agreement to sell the ethanol output from the plant to an oil company.
Negotiations are under way, he said, to sell the residue produced by the operation, perhaps for agricultural use since it may contain useful amounts of nitrogen.
