Factors contributing to deconstruction recalcitrance of herbaceous dicotyledons (forbs)
Monday, April 28, 2014
Exhibit/Poster Hall, lower level (Hilton Clearwater Beach)
Dina Jabbour, Evan R. Angelos, Melissa S. Borrusch and Jonathan D. Walton, Department of Energy Great Lakes Bioenergy Research Center, Michigan State University, East Lansing, MI
Many different feedstocks are under consideration for the practical production of biofuels from lignocellulosic materials. The use of low-input, high-diversity landscapes such as old fields, restored prairie, or marginal lands to grow biofuel feedstocks offers several potential benefits including minimal agronomic inputs, reduced competition with food production, and ecological advantages such as high biodiversity.

A number of studies have addressed the economic and environmental implications of producing biomass for bioenergy from low-input, high-diversity landscapes. A major component of such landscapes is often herbaceous dicotyledonous plants, also known as forbs. Although it has been found that landscapes with higher percent composition of grasses compared to forbs result in higher yields of fermentable sugars, it is difficult to elucidate the underlying reasons for the apparent superiority of grasses over forbs in natural plant communities. In order to minimize some of the variability innate in mixed communities, here we compared four individual forb species for yields of fermentable sugars, using corn stover (CS) as a benchmark. The forbs were lambsquarters (Chenopodium album), goldenrod (Solidago canadensis), milkweed (Asclepias syriaca), and Queen Anne’s lace (Daucus carota). Factors studied included glucose (Glc) content, response to pretreatments, presence of enzyme inhibitors, and enzymatic digestibility.          

Based on our findings, the potential utilization of forb-rich plant communities as biofuel feedstocks must take into account their lower Glc content compared to grasses such as corn stover. Furthermore, new enzyme mixtures tailored to the different cell wall composition of forbs will have to be developed.