Forage quality and composition measurements as predictors of ethanol yield from maize (Zea mays L.) stover.
BACKGROUND
Improvement of biofeedstock quality for cellulosic ethanol production will be facilitated by inexpensive and rapid methods of evaluation, such as those already employed in the field of ruminant nutrition. Our objective was to evaluate whether forage quality and compositional measurements could be used to estimate ethanol yield of maize stover as measured by a simplified pretreatment and simultaneous saccharification and fermentation assay. Twelve maize varieties selected to be diverse for stover digestibility and composition were evaluated.


RESULTS
Variation in ethanol yield was driven by glucan convertibility rather than by glucan content. Convertibility was highly correlated with ruminal digestibility and lignin content. There was no relationship between structural carbohydrate content (glucan and neutral detergent fiber) and ethanol yield. However, when these variables were included in multiple regression equations including convertibility or neutral detergent fiber digestibility, their partial regression coefficients were significant and positive. A regression model including both neutral detergent fiber and its ruminal digestibility explained 95% of the variation in ethanol yield.


CONCLUSIONS
Forage quality and composition measurements may be used to predict cellulosic ethanol yield to guide biofeedstock improvement through agronomic research and plant breeding.
Lorenz
Aaron J
AJ
Department of Agronomy, University of Wisconsin, Linden Drive, Madison, WI 53706, USA. alorenz@wisc.edu
Anex
Rob P
RP
Isci
Asli
A
Coors
James G
JG
de Leon
Natalia
N
Weimer
Paul J
PJ