Is bacteria cleantech's miracle drug?

Researchers at the Massachusetts Institute of Technology are discovering chemical factories in bacteria that absorb carbon monoxide and carbon dioxide, and that have the potential to replace petroleum as a component of fuels, textiles, chemicals and plastic.

Scientists are manipulating bacteria's abilities to break down atmospheric emissions and synthesize materials that are traditionally petroleum-based. As the backlog of emissions continues to grow and high oil prices raise the cost of fuel, plastics and textiles, bacteria's ability to step in becomes more commercially appealing.

MIT Chemistry Professor Catherine Drennan studies the way bacteria found in hot springs naturally absorb CO₂ and CO and use them to produce energy. These microbes eat up about 1 million tons of CO annually. Drennan uses X-ray crystallography, a method of bouncing X-ray beams through crystals to form an electron picture of the enzymes in the bacteria-pollutant reaction. Understanding how enzymes work may lead scientists to develop a catalyst that lowers CO levels in the atmosphere.

"These bacteria are responsible for removing a lot of CO and CO2 from the environment," Drennan in a news release about the work at MIT. "Can we use this chemistry to do the same thing?"

Drennan's work is mirrored in the commercial world, where cleantech companies are using microbes to clean polluted soil and water. Pittsburgh, Penn.-based aluminum producer Alcoa uses microbes and specialized plants and soils to reduce pollutants in discharged water (see How Alcoa is reducing discharges and contaminants at its aluminum facilities). Connecticut-based bioremediation company VeruTEK Technologies serves Fortune 500 companies with its natural chemistry products that eat soil and water toxins (see VeruTEK completes new green chemistry remediation project).

MIT chemical engineers Kristala Jones Prather and Gregory Stephanopoulos are targeting the petroleum-replacement field. Prather is developing bacteria that can produce butanol and pentanol biofuels when combined with agricultural feedstocks. Stephanopoulos is working to increase the bacteria’s tolerance to toxicity found in feedstocks and in the byproducts of the fuel production process.

The work has similarities in the commercial world. Pittsburgh, Penn.-based nano-biotechnology company NanoLogix grows bacteria in anaerobic bioreactors and uses them to metabolize sugars into carbon dioxide and hydrogen fuel (see NanoLogix using bacteria to produce hydrogen). Amherst, Mass.-based ethanol producer Qteros (formerly known as SunEthanol) uses microbes to convert plant material into ethanol (see Manufacturing microbes and Qteros claims 15-fold improvements in cellulosic ethanol yield).

And those companies have plenty of microbe-producing competitors, such as Iogen, Poet, DuPont Danisco Cellulosic Ethanol (see Another cellulosic powerhouse formed), BlueFire Ethanol, Broin Companies, and ALICO.

Bacteria also has advantages over petroleum in making plastics and textiles. Using petroleum makes the process energy intensive because of the high temperatures and pressure required. Bacteria requires a lower temperature—30 degrees Celsius—and low atmospheric pressure. Prather is working on bacteria that produce the biodegradable plastic polyhydroxyalkanoate (PHA) from transformed glucose.

"We’re trying to ask what kinds of things should we be trying to make, and looking for potential routes in nature to make them," Prather said in a news release about her work.

In the commercial sector, companies are using microbes to produce valuable textiles. San Diego-based biomanufacturing company Genomatica uses engineered E. Coli bacteria to consume sugar and produce butanediol (BDO), which is used in plastics, solvents, pharmaceuticals, automotive components and textiles (see Genomatica develops novel bioplastic). The global market for BDO is about $4 billion a year.

Prather has also found a new way to use plant, yeast and bacteria genes to compose glucaric acid for water treatment and nylon synthesis.

Other research by MIT scientists include using the natural power generated by trees to recharge battery operated sensors that can detect forest fires (see New ag-tech innovations show promise), developing renewable energy (see MIT, Fraunhofer set up energy research center), producing a solar-powered fridge for rural India (see MIT spin-off develops fridge for rural India), and researching best practices for carbon capture and storage (see MIT unlocking carbon capture and storage).

Cleantech developments making news in the past 24 hours

• Metabolix, ADM to open new bioplastics factory
• Rockwool nears construction on Indian insulation factory
• Two Israeli wastewater firms to locate in Michigan
• Al Gore: Super grid is critical to combating the climate crisis
• A quest for CO2 and O2 optimal management with biofuel from algae

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