Watching Plant Biomass Breakdown to Improve Biofuel Production
Sustainable and cost-effective production of biofuels from plant biomass is hindered by the cost of pretreatment and low sugar yields after enzymatic hydrolysis of plant cell wall polysaccharides. Many studies have looked at enzymatic action on individual biomass components, but in nature, the plant cell wall is a complex, networked structure that interacts concertedly with pretreatment enzymes. To fully understand the mechanisms of enzymatic plant cell wall deconstruction for optimal production of bioenergy from biomass, it is imperative to understand the whole system. Scientists at the U. S. Department of Energy’s (DOE) BioEnergy Science Center (BESC) and DOE National Renewable Energy Laboratory (NREL) have addressed this problem by using a combination of advanced microscopic imaging methods in a correlative, real-time manner to examine both fungal and bacterial enzyme systems. With this new technology, they are able to localize the enzymatic sites of action without compromising the cell wall’s structural integrity. The results suggest that an optimal strategy for enhancing fermentable sugar yield from enzymatic deconstruction is to modify lignins to be more amenable to removal through pretreatment while maintaining polysaccharide integrity, improving accessibility to enzyme action.
Ding, S.-Y., Y.-S. Liu, Y. Zeng, M. E. Himmel, J. O. Baker, and E. A. Bayer. 2012. “How Does Plant Cell Wall Nanoscale Architecture Correlate with Enzymatic Digestibility?” Science 338(6110), 1055–60. DOI: 10.1126/science.1227491.