Today, almost all commercially produced plastics are made from petroleum and aren’t biodegradable.
Enter Oliver Peoples, chief scientific officer and his team of researchers at Metabolix in Cambridge, MA. The team is genetically engineering switchgrass, a plant that thrives on marginal land, to produce a biodegradable polymer, PHA, extracted directly from the plant.
After processing, the leftover grass could be burned as a biomass energy source.
More than 20 years ago, Peoples and his MIT biology professor colleague, Anthony Sinskey, founded Metabolix. They discovered metabolic genes that allow bacteria found in soil to naturally produce the biodegradable polymer.
Currently, they’re working on inserting those genes into plants such as switchgrass, camelina and sugarcane. The researchers are focusing on coaxing switchgrass to produce and store in its tissues a specific type of PHA called PHB that can be used to injection mold products such as electronics housings.
To be economically competitive with other sources of biodegradable plastics, Metabolix says the grass must produce 10% of its weight as PHB. The team of scientists had doubled the PHB in switchgrass from 1.2% in 2008 to 2.3% in 2012, with 7% in the leaves. Once the 10% goal is reached, the company could sell the plant-based polymer for less than half of current polymer prices.
Peoples describes the progress the company has made and will yet make as “. . . a testament to sheer bloody single-mindedness.”
Source: MIT Technology Review, June 5, 2013 Smart Planet Daily, June 6, 2013