Rapid selection and identification of Miscanthus genotypes with enhanced glucan and xylan yields from hydrothermal pretreatment followed by enzymatic hydrolysis

Background: Because many Miscanthus genotypes can be cultivated with relatively high productivity and carbohydrate content, Miscanthus has great potential as an energy crop that can support large scale biological production of biofuels. Results: In this study, batch hydrothermal pretreatment at 180 degrees C for 35 min followed by enzymatic hydrolysis was shown to give the highest total sugar yields for Miscanthus x giganteus cv. Illinois planted in Illinois. High throughput pretreatment at 180 degrees C for 35 min and 17.5 min followed by co-hydrolysis in a multi-well batch reactor identified two varieties out of 80 that had significantly higher sugar yields from pretreatment and enzymatic hydrolysis than others. The differences in performance were then related to compositions of the 80 varieties to provide insights into desirable traits for Miscanthus that enhance sugar yields. Conclusions: High throughput pretreatment and co-hydrolysis (HTPH) rapidly identified promising genotypes from a wide range of Miscanthus genotypes, including hybrids of Miscanthus sacchariflorus/M. sinensis and Miscanthus lutarioriparius, differentiating the more commercially promising species from the rest. The total glucan plus xylan content in Miscanthus appeared to influence both mass and theoretical yields, while lignin and ash contents did not have a predictable influence on performance.