I am a PhD student in the IGERT-MASB program (http://bioenergy-igert.colostate.edu/index.php) and PMPB (http://www.plantbiology.colostate.edu/). My research investigates how extensins influence the ease with which cell walls can be converted to biofuel. Extensins are integral cell wall proteins that seem to be covalently bound to some component of the cell wall and are exceptionally hard to remove through chemical methods. Currently, biomass pretreatment techniques rely on chemical methods. Extensins therefore may remain bound in the cell wall after pretreatment, so that the cell wall is not as easy to digest as it could be and the yield of fermentable monosaccharides is low.

I am testing this hypothesis in three ways. First, I have analyzed poplar wood and found that extensins do remain in the biomass after pretreatment with liquid hot water or dilute acid. I will now test whether protease treatment to digest the extensins causes more monosaccharides to be released from the biomass after pretreament and digestion. Second, I am analyzing Arabidopsis mutants that do not produce certain extensin proteins or enzymes required for post-translational modification of extensins. These mutants should release more monosaccharides after pretreatment and digestion than wild-type plants. Finally, I am creating transgenic Arabidopsis plants that express a partial extensin protein fused to a fluorescent reporter protein. These transgenic plants should be less digestible than wild-type plants, and will also provide a way to monitor extensins in vivo.

Kanamycin screen for transgenic plants