Uses of miscanthus press juice within a green biorefinery platform.

This study assesses some uses of nutrient-rich juice mechanically extracted from freshly harvested Miscanthus x giganteus (MxG) as part of a green biorefinery system. The juice was used for culturing Saccharomyces cerevisiae and lactic acid bacteria. MxG juice was further used as substrate for fermentation to produce lactic acid using Lactobacillus brevis and Lactobacillus plantarum. The results show that MxG juice was a highly nutritious source for the cultivation of bacteria. Higher concentrations of MxG juice used as culture media, resulted in higher cell growth both aerobically and anaerobically. The highest ethanol yield of 70% theoretical and concentration of 0.75g/100ml were obtained from S. cerevisiae cultivated with 90% (v/v) MxG juice media and used for miscanthus solid fraction fermentation. 11.91g/L of lactic acid was also successfully produced from MxG juice through SSF.

Effects of fertilizer application and dry/wet processing of Miscanthus x giganteus on bioethanol production.

The effects of wet and dry processing of miscanthus on bioethanol production using simultaneous saccharification and fermentation (SSF) process were investigated, with wet samples showing higher ethanol yields than dry samples. Miscanthus grown with no fertilizer, with fertilizer and with swine manure were sampled for analysis. Wet-fractionation was used to separate miscanthus into solid and liquid fractions. Dilute sulfuric acid pretreatment was employed and the SSF process was performed with saccharomyces cerevisiae and a cocktail of enzymes at 35°C. After pretreatment, cellulose compositions of biomass of the wet samples increased from 61.0-67.0% to 77.0-87.0%, which were higher than the compositions of dry samples. The highest theoretical ethanol yield of 88.0% was realized for wet processed pretreated miscanthus, grown with swine manure. Changes to the morphology and chemical composition of the biomass samples after pretreatment, such as crystallinity reduction, were observed using SEM and FTIR. These changes improved ethanol production.