Friedrich Srienc is developing versatile and affordable bio-based plastics.
Bioplastics may be the buzzword for today's graduates
By Terri Peterson Smith
December 16, 2005
"I want to say one word to you. Just one word...Plastics"
When Dustin Hoffman's character, Benjamin Braddock, received that famous career tip in the 1967 movie The Graduate, the world of petroleum-based plastics was in its heyday. "Space-age" plastics turned up in everything from automobiles to shiny vinyl clothing. Now, in a world of diminishing oil reserves and burgeoning plastics that don't decompose, biologically-derived polymers hold even greater promise.
Yet, for the bioplastics industry to thrive, it must overcome two obstacles: cost and versatility. If bioplastics cost more than their petroleum-based counterparts, no one will use them, even if they're better for the environment. And these new bioplastics must offer an array of properties-strength, pliability, transparency, and formability, for example-to match petro-plastics.
Some bio-based polymers are already on the market. Cargill Dow's NatureWorks products, for example, are used in packaging, blankets, and wipes. Cargill Dow turns unrefined dextrose from corn into lactic acid from which a polymer is formed. These types of plastics have their limitations, however, such as intolerance to heat.
In contrast, polyhydroxyalkanoates (PHAs), a family of biodegradable polymers naturally synthesized by bacteria as carbon and energy reserve materials, offers promise. Friedrich Srienc, a native of Austria who came to the University of Minnesota in 1985, works with PHAs. He and a cadre of other researchers in the Biotechnology Institute are tackling the issues of cost and versatility in biopolymer production. They have received IREE grants for two major projects. The first is a $270,000 three-year grant with which Srienc and Romas Kazlauskas, an associate professor in the Department of Biochemistry, Molecular Biology and Biophysics, seek to develop new yeast strains capable of synthesizing polymers under anaerobic conditions. Anaerobic (in absence of oxygen) processing requires less energy, which reduces the cost. Srienc maintains that coupling PHA production with ethanol production (using the same biological raw materials) will improve the economic viability of both biopolymer and ethanol production.
The second is a three-year, $429,000 grant funding work in which Srienc is collaborating with Kazlauskas and Claudia Schmidt-Dannert, associate professor in the Department of Biochemistry, Molecular Biology, and Biophysics. Combining their expertise in enzyme-catalyzed synthesis, biosynthetic pathway engineering, and metabolic network engineering, they are working to develop a new class of polymers with electrical conducting properties, or electronic plastics. Such plastics are currently synthesized from petroleum and are used in lasers, ultra-fast image processors, thin-film transistors, highly sensitive plastic photodiodes, and integrated circuits.
So, Benjamin Braddock might receive the same advice today as he did in the '60s. But if Srienc and company achieve their goals, the word will be... bioplastics.