Turning Grass into Usable Biofuels

Lignocellulosic biomass is an abundant renewable resource available for the production of biofuels and other value-added products including polyhydroxyalkanoate (PHA) bioplastics. Due to the recalcitrant nature of lignin, biomass requires costly pretreatment to free polysaccharides for the enzymatic hydrolysis to fermentable sugars. As a result of their immense environmental adaptability and biochemical versatility, bacteria are being studied for their ability to directly convert lignin into bioplastics. A bacterial consortium was derived from soil samples from the Harvard Forest and maintained on media containing lignin as a sole carbon source under anaerobic conditions. The community was screened for PHA production, and bacteria capable of bioplastics production were isolated and identified. Further experiments were conducted to synthesize PHAs directly from lignin or lignin derivatives as the sole carbon source. Such research may allow for future applications of lignin-based biomass processing with the additional advantage of co-product production.