Engineered Microbes Key to Producing Plastic from Plants

Researchers at the University of Wisconsin hope to turn woody plants into a replacement for petroleum in producing fuels and other chemicals and are after the sugars in cellulose that makes up much of plant cell walls.

Getting those sugars involves stripping away lignin, the polymer that fills the gaps between cellulose and other chemical components in cell walls. Lignin never carried much value, and lignin stripped from wood to make paper is simply burned.

Enter the bacterium Novosphingobium aromaticivorans, a biological funnel for the aromatics in lignin, and which can digest nearly all of the different pieces of lignin into smaller hydrocarbons. During digestion, the microbe turns aromatic compounds into 2-pyrone-4,6-dicarboxylic acid (PDC). By removing three genes from the microbe, the intermediate PDC comes to the end of the line. These engineered bacteria became a funnel where lignin pieces go, and out of which PDC flows. The researchers found that PDC performs the same or better than most common petroleum-based additive to PET polymers such as plastic bottles and synthetic fibers. 

Read more details in University of Wisconsin News.