Biodegradable Plastic Polymer from GM Switchgrass

Scientists from the US based company Metabolix Inc. have developed transgenic switchgrass accumulating high levels of the polymer polyhydroxybuterate (PHB). PHB, usually produced by microorganisms during stress conditions, has attracted attention because it has properties similar to the thermoplastic polymer polypropylene. Unlike polypropylene, PHB is biodegradable. Biodegradable plastics can significantly reduce petroleum consumption and may prove to be beneficial for the environment. The high cost of PHB production compared to plastics produced from petrochemicals, however, limits its widespread commercial use.

PHB production was monitored in more than 400 switchgrass transformants grown under in vitro and glasshouse conditions. The GM switchgrass accumulated as much as 3.72% dry weight of the polymer in leaf tissues and 1.23% dry weight of PHB in whole tillers. The study presents the first successful expression of a functional multigenic pathway in switchgrass.

The abstract of the article published by the Plant Biotechnology Journal is available at http://www.blackwell-synergy.com/doi/abs/10.1111/j.1467-7652.2008.00350.x