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We have developed a relatively simple simultaneous saccharification and fermentation (SSF) technique to determine the ethanol production potential for large sets of biomass samples. The technique is based on soaking approximately 0.5 grams of a biomass sample in aqueous ammonia at room temperature and at atmospheric pressure for 24 h, then fermenting with Saccharomyces cerevisiae D 5 A for 24 h using Spezyme CP, for enzymatic hydrolysis of structural polysaccharides. We have tested the technique on a set of corn stover samples representing much of the genetic variability in the commercial corn hybrid population. The samples were weighed into modified Ankom filter bags (F57) before soaking to avoid biomass loss during the process. Fermentation samples were analyzed for ethanol after 24 h by HPLC. Percentages of theoretical maximum ethanol yields of the samples ranged between 44.9 and 73%. We observed that percentages of theoretical maximum ethanol yields were highly correlated (r 2 =0.90) with acid detergent lignin concentration while a low correlation was observed between cellulose concentration and ethanol yield. Near infrared spectra of corn stover samples were also examined. The coefficient of determination (r 2 ) from regression of predicted versus measured percent theoretical maximum ethanol yield was 0.96. This result suggests that using NIRS is a promising method for predicting ethanol yield, but larger calibration sets are necessary for obtaining improved accuracy for larger sample populations. We conclude that the developed SSF technique could be applied to large numbers of biomass samples to rapidly estimate ethanol yields and to compare different biomass samples in terms of ethanol yields.

There were several methods that were well suited for predicting the digestible portion of forage materials, with the acid detergent lignin and Klason lignin method giving the highest correlation across the three types of forage. The continued use of Na₂SO₃ during preparation of Van Soest fibres needs to be evaluated owing to its ability to reduce lignin concentrations and effectiveness in predicting the utilisation of feedstuffs and feedstocks. Because there was little correlation between the lignin concentration and the biomass materials, there is a need to examine alternative or develop new methods to estimate lignin concentrations that may be used to predict the availability of carbohydrates for ethanol conversion.

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