Location: Bioproduct Chemistry and Engineering Research
Title: Plant cell walls to ethanol.
Submitted to: Biochemical Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 27, 2011
Publication Date: March 1, 2012
Citation: Jordan, D.B., Bowman, M.J., Braker, J.D., Dien, B.S., Hector, R.E., Lee, C.C., Mertens, J.A., Wagschal, K.C. 2012. Plant cell walls to ethanol. Biochemical Journal. 442:247-252.
Interpretive Summary: Conversion of plant cell walls to ethanol is a multi-step process (pretreatment, enzymatic hydrolysis, and fermentation) in which each stage presents a multitude of challenges. This paper describes the key hurdles that must be surpassed and presents new data that illustrates some of the various problems.
Conversion of plant cell walls to ethanol constitutes generation 2 bioethanol production. The process consists of several steps: biomass selection/genetic modification, physiochemical pretreatment, enzymatic saccharification, fermentation, and separation. Ultimately, it is desired to combine as many of the biochemical steps as possible in a single organism to achieve consolidated bioprocessing (CBP). A commercially-ready CBP organism is currently unreported. Production of generation 2 bioethanol is hindered by economics, particularly in the cost of pretreatment (including waste management and solvent recovery), the cost of saccharification enzymes (particularly exocellulases and endocellulases displaying kcat ~1 s-1 on crystalline cellulose), and the inefficiency of cofermentation of five and six carbon monosaccharides (owing in part to redox cofactor imbalances in Saccharomyces cerevisiae).