Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
During the pretreatment of lignocellulosic biomass, inhibitors are often created from the degradation of sugars and the release of lignin monomers. Much of the research in this area focuses on growth and production of biofuels in the presence of one or a couple components of the hydrolysate, such as furfural, acetate, or 5-hydroxymethyl furfural. Few studies, however, evolve for tolerance in an industrially relevant hydrolysate. The goal of this work was to use continuous fermentation to evolve for a strain of Saccharomyces cerevisiae that thrives in hydrolysate from dilute-acid pretreated Miscanthus. To determine the inhibitory concentration and a starting point for evolution, S. cerevisiae was grown in increasing concentrations of hydrolysate under anaerobic conditions. The growth and ethanol production significantly decreased in 15% (v/v) hydrolysate. Continuous fermentation was used to evolve a robust strain with improved growth and ethanol production in hydrolysate. To understand what genomic mutations conferred hydrolysate tolerance, efforts are underway to sequence the genome of the evolved strain.