Title: Plant cell walls to ethanol. Authors
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.
Technical Abstract: 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).