Fig. 3

Fractional total carbohydrate solubilization (a) and normalized gas production (b) for switchgrass fermentation by C. thermocellum with and without augmentation by either cotreatment or cosolvent-enhanced lignocellulosic fractionation (CELF). COMT(+) is a transgenic plant line with a down-regulated lignin pathway. COMT(−) is the control plant line. Solubilization results (a) are based on equal glucan loadings after 120 h of incubation from duplicate fermentation runs. Error bars for solubilization results represent one standard deviation and are based on biological replicates. For each solubilization bar, one representative gas production data set is shown (b); gas production data are a percentage of each respective maximum gas production value after 120 h.. An asterisk (*) indicates that the difference in solubilization between cotreatment and CELF was statistically significant at p ≤ 0.05. Details of the statistical analysis are presented in Additional file 2: Table S4