Escherichia coli (E. coli) can give you a severe case of food poisoning or, with a little genetic engineering, a useful plastic. Scientists at San Diego–based Genomatica, Inc., have announced success in manipulating the bacteria to directly produce butanediol (BDO), a chemical compound used to make everything from spandex to car bumpers, thereby providing a more energy-efficient way of making it without oil or natural gas.

"We have engineered the organism such that it has to secrete that product in order for it to grow," says bioengineer Christophe Schilling, president and co-founder of the company, launched in 2000 to develop such chemical-producing microbes. "The interests of the organism are aligned with our interests: It grows faster when it produces more."

The E. coli can be grown in large fermentation tanks, exactly like those used to brew ethanol from corn, and have also been genetically tweaked to tolerate high concentrations of BDO in their water. "Originally, BDO was toxic to E. coli at fairly low levels but we evolved the organism such that it now tolerates the concentration we need it to grow at," Schilling says. "We grow the bacteria in sugar and water to produce the product, then purify and separate that product out of that water."

Schilling and his colleagues are attempting to produce BDO first precisely because current methods of making it require are so energy-intensive. "You need some significant energy," says chemist Herbert Exner, an executive in charge of producing BDO and other chemicals in the U.S. at Germany-based chemical giant BASF, one of the largest BDO manufacturers in the world.

In addition, BDO itself is getting more expensive, rising from below $1 to around $1.22 per pound for bulk orders, Exner says. "Natural gas and oil peaked in the last 12 months and all processes are either gas or oil related," he says. "Therefore, by nature, the raw material costs went up, so also the prices for BDO went up."

Cost will be the ultimate factor in whether this someday becomes a widely used plastic-making process; Genomatica says it's not sure how much its E. coli–produced BDO will cost, noting that results thus far have been confined to the lab.

But the company calculates that their process (even including all the energy needed to gather and transport the raw feedstocks, ranging from sugar to cellulose) requires only 32,000 British thermal units (Btus) of energy, at least 30 percent less than traditional methods. CEO Christopher Gann says the company plans to use "inexpensive, readily available, nonfood-competing renewable feedstocks." Then the E. coli can turn these waste sugars into BDO at normal pressure and temperatures under 105 degrees Fahrenheit (40 degrees Celsius), unlike the petroleum alternatives.

"This isn't an aberration where we need $250 per barrel oil to be cost competitive," Gann adds. He says the researchers so far have produced less than two pounds (a kilogram) of BDO; he expects a pilot plant to be up and running next year.

"Natural gas or oil are materials that could one day be gone," BASF's Exner says. But "major industries, such as auto manufacturers are not willing to pay a significantly higher price just because you gave your product a bio-label."

Given that three billion pounds (1.4 billion kilograms) of BDO are produced annually relatively cheaply, Genomatica has a long way to go. But the company suggests that its genetically engineered E. coli may prove a more sustainable way of producing a range of necessary plastic compounds in the future.

"We selected BDO to start with because it's a product that is relatively sophisticated in the sense of the number of steps to make it starting from oil and gas," Gann says. "In our case, we start with land and water and sunshine to end up with sugar in water to produce BDO. The important competitive advantage is less energy and a much friendlier environmental footprint."

6 Comments

1. 1. Malky 08:51 PM 9/23/08

   Well that's fine and dandy; But has anyone make a study to find out what is the degradable point of the material, what does it matter that you could come out with a replacement for plastic if its going to take 500 years just like plastic to degrade. We need material that's going to degrade very quick so it wont last for ever and it wont be hanging around trees and killing Sea Lions and other sea creatures. Any material that we develop we must take into consideration the rate that it will take for deterioration, otherwise we are just creating another possible Environmental catastrophe. Think about that OK.

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2. 2. verdai 07:39 PM 9/24/08

   right.
   however, i want to be sure they can deliver fabric (Not as fragile as cotton) as well.
   ok?

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3. 3. catwho in reply to Malky 10:57 PM 9/24/08

   A student in Canada has already solved the problem of breaking down plastic, also with bacteria, by selectively breeding strains of bacteria that eat plastic. Instead of taking 500 years to degrade it, those little bugs can do it in about 100 days. I think the student won the national science fair award for that experiment.

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4. 4. dharmapeace 09:40 AM 9/25/08

   What happens when this stuff gets loose in the environment? Plastic World! J
   
   

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5. 5. not2far 04:05 PM 9/30/08

   How about trying to find bacteria that will dissolve all the plastic that is polluting our planet?

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6. 6. Saitoku03 05:00 PM 9/30/08

   Wow you guys are asking a lot! Don't you understand that if something like this becomes the industry standard that ~three billion pounds of CO2 removed from the atmosphere a year. Plus the 30% reduction in energy which was most likely gained from burning coal, add on top of that the all the reductions that come along with eliminating the processing of conventional BDO (i e the oil). This concept attacks the climate crisis on all three fronts while going as far as making it more affordable for everyone. If this works the way they want, its one of the first steps to creating a sustainable industrial economy.

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