One word: bioplastics

Nov 17, 2009 by Anne Trafton
Graphic: Christine Daniloff

(PhysOrg.com) -- Every year, more than 250 billion pounds of plastic are produced worldwide. Much of it ends up in the world's oceans, a fact that troubles MIT biology professor Anthony Sinskey.

does not degrade in the ocean. It just gets ground up into tiny particles,” he says. In the , a vast swath twice the size of Texas teems with tiny bits of oil-based plastic that can poison ocean life.

Sinskey can’t do much about the plastic that’s already polluting the Earth’s oceans, but he is trying to help keep the problem from getting worse. Next month, a company he founded with his former postdoc, Oliver Peoples, will open a new factory that uses MIT-patented technology to build plastic from corn. The plant aims to produce annually 110 million pounds of the new bioplastic, which biodegrades in soil or the ocean.

That’s a fraction of one percent of the United States’ overall plastic production, which totaled 101.5 billion pounds in 2008. Though it will take bioplastics a long time before they can start making a dent in that figure, the industry has significant growth potential, says Melissa Hockstad, vice president for science, technology and regulatory affairs for SPI: The Plastics Industry Trade Association.

“Bioplastics are making inroads into new markets and are an important area to watch for the future of the plastics industry,” says Hockstad, who noted that the current global market for biodegradable polymers is estimated at about 570 million pounds per year but is expected to more than double by 2012.

‘Timing is everything’

For Sinskey and Peoples, the road started 25 years ago. Peoples, who had just earned his PhD in from the University of Aberdeen, arrived in Sinskey’s lab in 1984 and set out to sequence a . Today, high-speed sequencing machines could do the job in about a week. Back then, it took three years.

That gene, from the bacterium R. eutropha, turned out to code for an enzyme that allows bacteria to produce polyhydroxyalkanoate (PHA) — a naturally occurring form of polyester — starting with only sunlight, water, and a carbon source. (Bacteria normally manufacture PHA as a way to store carbon and energy.)

Sinskey and Peoples realized that if they could ramp up the bacteria’s plastic producing abilities, they could harness the organisms for industrial use. In 1994, they started a company called Metabolix and took out exclusive patents from MIT on the gene work they had done on PHA-synthesizing bacteria.

Thus began a 15-year effort to develop the technology into a robust, large-scale process, and to win support for such an approach.

On the scientific side, Peoples and the scientists at Metabolix developed a method to incorporate several genes from different bacteria into a strain of E. coli. Using this process, now called metabolic engineering, they eventually created a strain that produces PHA at levels several-fold higher than naturally occurring bacteria.

However, they had some difficulty generating support (and funding) for the idea. In the early 1990s, the public was not very receptive to the idea of alternative plastics. “Oil was $20 a barrel, and people didn’t believe in global warming,” Peoples recalls.

“Timing is everything,” says Sinskey. “There has to be a market for these materials” for them to be successful.

‘Growing interest’

The scientists believe that consumers are now ready for bioplastics. Such plastics have been commercially available for about a decade, mostly in the form of plastic cups, bottles and food packaging. Most of those products are made from a type of plastic called polylactic acid (PLA), which is also produced from corn. PLA is similar to PHA, but PHA has higher heat resistance, according to Peoples.

Possible uses for the Metabolix bioplastics include gift cards, pens, golf tees and other consumer products. Products like these, along with existing bioplastic products, tap into a “growing interest in materials that can be made from renewable resources or disposed of through practices such as composting,” says Hockstad.

The new Metabolix plant, located in Clinton, Iowa, is a joint venture with Archer Daniels Midland. Although the plant is using corn as a starting material, the process also works with other materials such as cellulose (including switchgrass), vegetable oil and cane sugar.

Turning to those agricultural starting materials could help reduce the amount of petroleum needed to manufacture traditional plastics, which currently requires about 2 million barrels of oil per day (10 percent of total U.S. daily oil consumption). “It’s important to develop alternative ways to make these chemicals,” says Peoples.

Provided by Massachusetts Institute of Technology (news : web)

Explore further: Mantis shrimp stronger than airplanes

add to favorites email to friend print save as pdf

Related Stories

'Green' plastics could help reduce carbon footprint

Feb 11, 2009

More than 20 million tons of plastic are placed in U.S. landfills each year. Results from a new University of Missouri study suggest that some of the largely petroleum-based plastic may soon be replaced by a nonpolluting, ...

Microbes convert 'Styrofoam' into biodegradable plastic

Feb 23, 2006

Bacteria could help transform a key component of disposable cups, plates and utensils into a useful eco-friendly plastic, significantly reducing the environmental impact of this ubiquitous, but difficult-to-recycle waste ...

Huge potential for bioplastics

Jul 17, 2006

It almost sounds too good to be true - turning cow pats into plastic. But the unlikely-looking liquid in the flask Dr Steven Pratt holds is the key ingredient to an environmentally friendlier drink bottle.

Recommended for you

Mantis shrimp stronger than airplanes

22 hours ago

(Phys.org) —Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, ...

New mineral shows nature's infinite variability

Apr 22, 2014

(Phys.org) —A University of Adelaide mineralogy researcher has discovered a new mineral that is unique in structure and composition among the world's 4,000 known mineral species.

User comments : 4

Adjust slider to filter visible comments by rank

Display comments: newest first

holoman
not rated yet Nov 17, 2009
This is a very old idea.

The main problem I have with it is we already have 1 billion people going hungry in world and 1 in 6 Americans going hungry.

If we keep using food for fuel the numbers will climb.

defunctdiety
not rated yet Nov 17, 2009
I agree with you, holoman. But, if this bacteria can metabolize PHA from corn, hopefully it is a small step to use any organic waste towards the same end (says it just needs a "carbon source")?
uses...include gift cards, pens, golf tees and other consumer products

Hopefully this includes individual candy/food/item packaging, shopping sacks, and some of the other worst plastic offenders. Obviously it probably won't fly for water and soda containers, so that's a large source it won't eliminate, but it's a start.

Real solutions for real environmental problems. Cheers, MIT.
Gresh
not rated yet Nov 18, 2009
Did you two RTFA?

"Although the plant is using corn as a starting material, the process also works with other materials such as cellulose (including switchgrass), vegetable oil and cane sugar."

Cellulose can be found in abundance, in something that does not consume a square metre of farm land, kelp. Not only does it remove CO2 from the ocean, but also nutrient run off.
denfire
not rated yet Nov 19, 2009
cost is everything. no money mongoring business savy corporate type will ever invest in making his product more expensive to produce, or absorb the cost of buying what will surely be a more expensive raw material because it will thin his profit margin. that is why PET, PP, PE and others will be around poluting our earth until legislation is passed!

More news stories

Mantis shrimp stronger than airplanes

(Phys.org) —Inspired by the fist-like club of a mantis shrimp, a team of researchers led by University of California, Riverside, in collaboration with University of Southern California and Purdue University, ...

Male-biased tweeting

Today women take an active part in public life. Without a doubt, they also converse with other women. In fact, they even talk to each other about other things besides men. As banal as it sounds, this is far ...

High-calorie and low-nutrient foods in kids' TV

Fruits and vegetables are often displayed in the popular Swedish children's TV show Bolibompa, but there are also plenty of high-sugar foods. A new study from the University of Gothenburg explores how food is portrayed in ...