10-04: Application of high throughput systems to assess agave as a feedstock to grow on semi-arid lands for biological conversion to ethanol

An important issue slowing development of technologies for making biofuels is concern about possible competition for land and the resulting impacts on food supply. However, because agave offers high productivity with low water and nutrient demands, it can thrive on semiarid lands not suitable for conventional agriculture, making it a promising lignocellulosic feedstock for biofuels production. However, biomass recalcitrance is the key impediment to commercial applications of cellulosic biomass, and there is a critical need for systematic research to identify features of agave species and their impact on sugar release.  Thus, high throughput systems were applied to determine carbohydrate content of agave and screen pretreatment conditions and enzyme formulations. First, a new rapid analysis method we developed was applied to estimate sugar contents of six agave samples: A. fourcroydes, A. tequilana, A. americana, A. mapisaga, A. salmiana, and A. durangensis.  Then, our novel high throughput pretreatment and hydrolysis (HTPH) system was employed to evaluate the effect of enzyme loadings and formulations in combination with hydrothermal as well as dilute acid and sodium hydroxide pretreatments on sugar yields. In addition, the HTPH system enabled investigation of variations in sugar release with plant age and location and the importance of sampling technique for these agave species.  Results from these studies will provide a baseline of sugar release performance, help understand recalcitrance features of different agave species, and identify promising directions for detailed studies.