Research Highlights

Muconic acid is a chemical building block that can be used to make plastics such as those used in food and drink packaging, which are typically made from fossil fuels. Here, scientists genetically modified strains of the soil bacterium Novosphingobium aromaticivorans that produce muconic acid from an underused but abundant type of plant fiber called lignin.

Xylose is the second-most abundant sugar in plant biomass. Most yeasts cannot eat xylose even though many have the required genetic pathway. This study showed that gene content is necessary but not sufficient for xylose metabolism and that codon optimization can be a predictor of this trait.

New research shows that one bacterium can be modified to simultaneously produce two valuable compounds from pretreated sorghum biomass: carotenoids, a group of organic pigments used in nutritional supplements, drugs, and cosmetics; and an acid called PDC that can be used to make plastics. The bacteria accumulate carotenoids within their cells, while they secrete PDC from the cells, providing two valuable products that can be easily separated in a single batch. 

Terpenes and variations called terpenoids are chemicals produced by many plants that are responsible for distinctive scents and flavors. Terpenes also serve as signaling molecules that interact with the plant’s environment. GLBRC scientists sought to understand how terpenes and terpenoids affect the bacteria and fungi that live around the roots of two plant species, switchgrass and sorghum.

The study compared the root growth of two plant species in two types of soil to measure the effect of soil pore structure on roots. The findings show for some plants, soil structure plays a privotal role in how their roots grow and how long carbon from the plants remains in the soil.

Understanding epicuticular wax production and identifying the genes that regulate wax loads and composition could enable scientists to engineer more resilient bioenergy crops and improve the economics of biofuel production.

Compared to other components of the plant cell wall, MLG can be more easily converted into glucose, which microbes can ferment into alcohol. Understanding the role and mechanisms of MLG regulation could help scientists engineer bigger, faster-growing plants that store more carbon inside the cell walls and are more easily converted into biofuels. 

Researchers created a hybrid yeast that produces two types of biofuel, isobutanol and ethanol, from switchgrass. Using the lab results, they developed an economic model to estimate what it would cost to produce the fuels in a commercial plant and identified the key factors that could lower production costs.

Study reveals that photosynthesis declines in bioenergy switchgrass are triggered by a buildup of carbohydrates in its roots and rhizomes in preparation for overwintering.

In 2017, GLBRC scientists found two strains of bacteria that produced high levels of lipids by squeezing them out of their cell envelope, making the oil easier to harvest. Two new studies help explain the mechanisms these mutant bacteria use to shed their fat and reveal new ways to increase lipid secretion.