Mitigation of cellulose recalcitrance to enzymatic hydrolysis by ionic liquid pretreatment
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Efficient hydrolysis of cellulose-to-glucose is critically important in producing fuels and chemicals from renewable feedstocks. Cellulose hydrolysis in aqueous media suffers from slow reaction rates because cellulose is a water-insoluble crystalline biopolymer. The high-crystallinity of cellulose fibrils renders the internal surface of cellulose inaccessible to the hydrolyzing enzymes (cellulases) as well as water. Pretreatment methods, which increase the surface area accessible to water and cellulases are vital to improving the hydrolysis kinetics and conversion of cellulose to glucose. In a novel technique, the microcrystalline cellulose was first subjected to an ionic liquid (IL) treatment and then recovered as essentially amorphous or as a mixture of amorphous and partially crystalline cellulose by rapidly quenching the solution with an antisolvent. Because of their extremely low-volatility, ILs are expected to have minimal environmental impact. Two different ILs, 1-n-butyl-3-methylimidazolium chloride (BMIMC1) and 1-allyl-3-methylimidazolium chloride (AMIMC1) were investigated. Hydrolysis kinetics of the IL-treated cellulose is significantly enhanced. With appropriate selection of IL treatment conditions and enzymes, the initial hydrolysis rates for IL-treated cellulose were up to 90 times greater than those of untreated cellulose. We infer that this drastic improvement in the “overall hydrolysis rates” with IL-treated cellulose is mainly because of a significant enhancement in the kinetics of the “primary hydrolysis step” (conversion of solid cellulose to soluble oligomers), which is the rate-limiting step for untreated cellulose. Thus, with IL-treated cellulose, primary hydrolysis rates increase and become comparable with the rates of inherently faster “secondary hydrolysis” (conversion of soluble oligomers to glucose).
- Lynd, L. R., Weimer, P. J., van Zyl, W. H., and Pretorius, I. S. (2002), Microbiol. Mol. Biol. Rev. 66, 506–577. CrossRef
- Lynd, L. R., Wyman, C. E., and Gerngross, T. U. (1999), Biotechnol. Prog. 15, 777–793. CrossRef
- Zhang, Y. -H. P. and Lynd, L. R. (2004), Biotechnol. Bioeng. 88, 797–824. CrossRef
- Klemm, D., Philipp, B., Heinze, T., Heinze, U., and Wagenknecht, W. (1998), Fundamentals and analytical methods, Wiley-VCH, Weinheim.
- Ladisch, M. R., Ladisch, C. M., and Tsao, G. T. (1978), Science 201, 743–745. CrossRef
- Hamilton, T. J., Dale, B. E., Ladisch, M. R., and Tsao, G. T. (1984), Biotechnol. Bioeng. 26, 781–787. CrossRef
- Wood, T. M. (1988), Methods Enzymol. 160, 19–25. CrossRef
- Zhang, Y. -H. P. and Lynd, L. R. (2005), Biomacromolecules 6, 1510–1515. CrossRef
- Dadi, A., Varanasi, S., and Schall, C. A. (2006), Biotechnol. Bioeng. 95, 904–910; Varanasi, S., Schall, C, and Dadi, A; US Patent filed, December 2006. CrossRef
- Zhang, Y. -H. P., Cui, J., Lynd, L. R., and Kuang, R. L. (2006), Biomacromolecules 7, 644–648. CrossRef
- Lynd, L. R., van Zyl, W. H., McBride, J. E., and Laser, M. (2005), Curr. Opin. Biotech. 16, 577–583. CrossRef
- Heinze, T., Schwikal, K., and Barthel, S. (2005), Macromol. Biosci. 5, 520–525. CrossRef
- Swatloski, R. P., Spear, S. K., Holbrey, J. D., and Rogers, R. D. (2002), J. Am. Chem. Soc. 124, 4974–4975. CrossRef
- Wu, J., Zhang, J., He, J., Ren, Q., and Guo, M. (2004), Biomacromolecules 5, 266. CrossRef
- Moulthrop, J. S., Swatloski, R. P., Moyna, G., and Rogers, R. D. (2005), Chem. Comm. 12, 1557–1559. CrossRef
- Zhang, H., Wu, J., Zhang, J., and He, J. (2005), Macromolecules 38, 8272–8277. CrossRef
- Ghose, T. K. (1987), Pure Appl. Chem. 59, 257–268. CrossRef
- Miller, G. L. (1959), Anal. Chem. 31, 426–428. CrossRef
- Anderson, J. L., Ding, J., Welton, T., and Armstrong, D. W. (2002), J. Am. Chem. Soc. 124, 14,247–14,254.
- Crosthwaite, J. M., Aki, S. N. V. K., Maginn, E. J., and Brennecke, J. F. (2005), Fluid Phase Eq. 228–229, 303–309. CrossRef
- Segal, L., Creely, J. J., Martin, A. E., and Conrad, C. M. (1959), Text. Res. J. 29.
- Kleman-Leyer, K. M., Siika-Aho, M., Teeri, T. T., and Kirk, T. K. (1996), Appl. Envion. Microbiol. 62, 2883.
- Pereira, A. N., Mobedshahni, M., and Ladisch, M. R. (1988), Methods Enzymol. 160, 26–43.
- Shengdong, Z., Yuanxin, W., Qiming, C., et al. (2006), Green Chem. 8, 325–327. CrossRef
- Mitigation of cellulose recalcitrance to enzymatic hydrolysis by ionic liquid pretreatment
Applied Biochemistry and Biotechnology
Volume 137-140, Issue 1-12 , pp 407-421
- Cover Date
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- Humana Press
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- enzymatic hydrolysis
- pretreatment crystallinity index
- initial rates
- reducing sugars
- Industry Sectors