Proso millet (Panicum miliaceum L.) fermentation for fuel ethanol production

The objective of this research was to determine the conversion efficiency of proso millet to ethanol compared to corn in a bench-scale dry-grind procedure. Seven proso millet cultivars and six advanced breeding lines containing waxy starch were fermented with Saccharomyces cerevisiae and ethanol production was compared with normal corn and " highly fermentable" corn. The highly fermentable corn exhibited the highest fermentation efficiency (97.0 ± 1.4%). Among proso millet lines, those with the highest fermentation efficiencies were: Huntsman (85.9 ± 0.6%), 172-2-9 (90.8 ± 0.2%), 172-2-13 (85.1 ± 2.5%), and 182-4-24 (84.7 ± 2.1). Waxy proso millet lines resulted in higher fermentation efficiencies than the non-waxy proso millet varieties containing normal starch (82.4 ± 5.5% vs. 75.5 ± 7.4%, respectively, p= 0.01). Proso millet distiller's dried grains with solubles (DDGS) contained more protein (26.6-33.4%) than the DDGS from corn (17.2-23.4%). These data indicate that proso millet exhibits promise as a feedstock for ethanol production, especially if breeding programs focus on selecting " highly fermentable" lines for advancement.