ARS | Publication request: Evaluating low lignin mutants of forage sorghum for increased conversion efficiency to sugars and ethanol

Submitted to: Biotechnology for Fuels and Chemicals Symposium Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: May 7, 2008
Publication Date: May 7, 2008
Citation: Dien, B.S., Sarath, G., Pedersen, J.F., Funnell-Harris, D.L., Sattler, S.E., Nichols, N.N. 2008. Evaluating low lignin mutants of forage sorghum for increased conversion efficiency to sugars and ethanol. Biotechnology for Fuels and Chemicals. p. 267.

Technical Abstract: Reduced lignin near-isogenic lines of Atlas bmr-6, bmr-12, and bmr-6 bmr-12 forage sorghum (Sorghum biocolor (L.)) were evaluated as sources of biomass for conversion to sugars and ethanol. These mutants have the advantage of reduced lignin contents and high biomass yields. Field replicates of wild-type and multiple reduced lignin mutants were harvested whole and without grain, dried, and ground. Representative biomass samples were evaluated for total carbohydrate, Klason lignin, and ash contents. Lignin varied widely and total carbohydrates less so. Samples were next treated with a low-severity dilute-acid pretreatment and the washed solids saccharified with commercial cellulase. The relative amount of glucose released (63-90%) was found to be negatively correlated with lignin content and the correlation was 0.80. Currently, the washed solids are being evaluated for differences in ethanol yields following simultaneous saccharification and fermentation with Saccharomyces cerevisiae.