THE GREEN PLASTIC
Looking to plants for production of new, environmentally friendly plastic

Tucked away in LSU’s little-known, former Food Services Building, scientists are making use of long forgotten freezers and butcher blocks to shape the next innovation in environmentally-friendly materials and looking to a Louisiana staple export to provide the means to produce it. The building is home to LSU’s Institute for Ecological Infrastructure Engineering (EiEL).

Researchers from EiEL and LSU’s School of Human Ecology are advancing developments in a new, unfamiliar substance known as bioplastic—plastic that can be thrown into your family’s compost pile and biodegrade in a few months. Similar to its synthetic cousin that most of us are familiar with, bioplastic is different from other plastics in that it is made in plants or microbes.

“One obvious benefit of bioplastic is that it is environmentally friendly,” says Kelly Rusch, director of EiEL and the Formosa Plastics Endowed Professor in the LSU Department of Civil and Environmental Engineering. “Synthetic plastic is made from fossil fuels, which are in limited supply. Bioplastic will allow us to move away from using fossil fuels. Bioplastic will also reduce the amount of greenhouse gases being released into the atmosphere. It’s good for the planet.”

Besides limiting the use of fossil fuels, another major advantage of bioplastic is that it is biodegradable; however, that is not the most interesting aspect of this green substance. When the time comes for bioplastic to be commercially produced, production will not be done in the same manner as synthetic plastics, but will be produced in plants, potentially sugar cane.

Plants produce and store their energy mainly as sugars through a process known as photosynthesis. Scientists are working to modify the genetic coding of plants to produce bioplastic as the energy source instead. This change will allow carbon dioxide usually trapped and converted to energy by plants to be released when bioplastic biodegrades, resulting in no net increase of greenhouse gases in the atmosphere.

In the lab, bacteria produce plastic as a way to store energy through a process called bacterial fermentation—the same fermentation process that makes beer. However, the plastic is later reconverted back to energy as the bacteria need it. To prevent this process of reconversion, scientists simply remove the genes that cause it and the bacteria begin to store greater quantities of plastic that can be extracted. Researchers are already applying these same genetics techniques to switchgrass.

Funded by a grant from the Consortium for Plant Biotechnology Research, Rusch and her team, which includes Ioan Negelescu, a professor in LSU’s School of Human Ecology, are working with an industrial partner, Metabolix, a biotechnology company based in Cambridge, Massachusetts. Rusch and company are focusing on developing additives that will make bioplastic as durable and flexible as synthetic plastic, but remain biodegradable and environmentally friendly. Metabolix is working to bring bioplastics to the marketplace through their patented biotechnologies.

For the future, Rusch envisions networks of bioplants: large, environmentally-friendly factories that will pump out high volumes of the green matter we will know as bioplastic. The material will eventually find its way into the water bottles we drink from, the appliances we cook with, and the cars we drive.

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LSU Institute for Ecological Infrastructure Engineering

from Summer/Fall 2005