As a biomass and biofuel plant, switchgrass is also considered a potential crop for production of biodegradable plastics as a value-added co-product, which can "reduce petroleum consumption and decrease plastic waste disposal issues" (Somleva et al. 2008). In such an attempt, Metabolix, Inc. introduced bacterial genes into switchgrass to produce such a plastic, polyhydroxybutyrate (PHB) (Somleva et al. 2008). The enzymes encoded by the three transgenes for PHB synthesis were targeted to plastids to enhance PHB yield as previously demonstrated. Transgenic plants containing up to 3.7% dry weight of PHB in leaf tissues and 1.2% dry weight PHB in whole tillers were obtained. The PHB granules were accumulated in chloroplasts of the leaves. Most of the transgenic plants grew normally although affected growth was also observed. Transgenes and PHB production were inherited to offspring plants through both male and female gametes. Although the yield of PHB in these transgenic plants did not meet the 7.5% dry weight threshold estimated by Metabolix to be necessary for profitable commercialization, the authors believe it is the first step towards achieving the goal. It also demonstrated the amenability to introduce multiple genes to alter metabolic pathways in this important biofuel crop.

Current studies suggest that it is feasible to generate low-lignin switchgrass, improve biomass yield, and add value to this biofuel crop. Field tests on these various transgenic plants are needed to support the claims that the low lignin content, normal or increased biomass yield, and other improved traits of the transgenic lines still hold in various field conditions.