Abstract
Corn fiber is a grain-processing residue containing significant amounts of cellulose, hemicellulose, and starch, which is collected in facilities where fuel ethanol is currently manufactured. Preliminary research has shown that corn fiber (30% moisture dry weight basis [dwb]) responds well to ammonia-fiber explosion (AFEX) pretreatment. However, an important AFEX pretreatment variable that has not been adequately explored for corn fiber is sample moisture. In the present investigation, we determined the best AFEX operating conditions for pretreatment of corn fiber at high moisture content (150% moisture dwb). The optimized AFEX treatment conditions are defined in terms of the moisture content, particle size, ammonia to biomass ratio, temperature, and residence time using the response of the pretreated biomass to enzymatic hydrolysis as an indicator. Approximate optimal-pretreatment conditions for unground corn fiber containing 150% (dwb) moisture were found to be: temperature, 90‡C; ammonia: dry corn fiber mass ratio, 1:1; and residence time 30 min (average reactor pressure under these conditions was 200 pounds per square inch [psig]). Enzymatic hydrolysis of the treated corn fiber was performed with three different enzyme combinations. More than 80% of the theoretical sugar yield was obtained during enzymatic hydrolysis using the best enzyme combination after pretreatment of corn fiber under the optimized conditions previously described. A simple process for enzyme recovery and reuse to hydrolyze multiple portions of AFEX-treated corn fiber by one portion of enzyme preparation is demonstrated. Using this process, five batches of fresh substrate (at a concentration of 5% w/v) were successfully hydrolyzed by repeated recovery and reuse of one portion of enzyme preparation, with the addition of a small portion of fresh enzyme in each subsequent recycling step.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Bothast, R. J. (1994),Proc. Corn Utilization Conf. V, June 8–10, 1994, St. Louis, MO, National Corn Growers Association.
Wyman, C. E. (1994),Biores. Technol. 50, 3–16.
Nguyen, Q. A. and Saddler, J. N. (1991),Biores. Technol. 35, 275–323.
Bungay, H. R. (1985),Ann. N.Y. Acad. Sci. 434, 155–157.
Dale, B. E. (1985),Ann. Repts. On Ferm. Process. 8, Chap. 11, 299–323.
Weil, J., Westgate, P., Kohlmann, K., and Ladisch, M. R. (1994),Enzyme Microb. Technol. 16, 1002–1004.
Dale, B. E. and Moreira, M. J. (1983),Biotechnol. Bioeng. 12, 31–43.
Dale, B. E., Henk, L. L., and Shiang, M. (1985),Dev. Ind. Microbiol. 26, 233–233.
Holtzapple, M. T., Jun, J. H., Ashok, G., Patibandla, S. L., and Dale, B. E. (1991),Apple. Biochem. Biotech. 28/29, 59–74.
Holtzapple, M. T., Lundeen, J. E., Sturgis, R., Lewis, J. E. and Dale, B. E. (1992),Appl. Biochem. Biotech. 34/35, 5–21.
Tan, L. U. L., Yu, E. K. C, Mayers, P., and Saddler, J. N. (1987),Appl. Microbiol. Biotechnol. 26, 21–27.
Ooshima, H., Burns, D. S., and Converse, A. O. (1990),Biotechnol. Bioeng. 36, 446–452.
American Association of Cereal Chemists (1995), Approved Methods of the AACC, 9th ed., Section 76-20, Starch-Polarimetric Method, AACC, St. Paul, MN.
Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randalt, R. J. (1951),J. Biol. Chem. 193, 265–275.
Miller, G. L. (1959),Anal. Chem. 31(3), 426–428.
Hespell, R. B. and Cotta, M. A. (1995),Appl. Environ. Microbiol. 61, 3042–3050.
Mandels, M., Andreotti, R., and Roche, C. (1976),Biotechnol. Bioeng. Symp. 6, 21–33.
Chen, W. P. and Anderson, A. W. (1980),Biotechnol. Bioeng. 22, 519–531.
Wright, J. D., Power, A. J., and Douglas, L. J. (1986),Biotechnol. Bioeng. Symp. No. 17, 285–301.
Gharpuray, M. M., Lee, Y. H., and Fan, L. T. (1983),Biotechnol. Bioeng. 25, 157–172.
Brownell, H. H., Yu, E. K. C. and Saddler, J. N. (1986),Biotechnol. Bioeng.,28, 792–801.
Barry, A. J., Peterson, F. C. and King, A. J. (1936),J. Am. Chem. Soc. 58, 333–337.
Lewin, M. and Roldan, L. G. (1971),J. Polymer Sci. 36, 213–229.
Torkow, H. and Feist, W. C. (1969),Adv. Chem. Ser. 95, 197–218.
Wang, P. Y., Bolker, H. I., and Purves, C. B. (1967),Tappi 50(3), 123–124.
Weimer, P. J., Chou, Y. C. T., Weston, W. M., and Chase, D. B. (1986),Biotechnol. Bioeng. Symp. 17, 5–18.
O’Conner, J. J. (1972),Tappi 55(3), 353–358.
Clesceri, L. S., Sinitsyn, A. P., Saunders, A. M., and Bungay, H. R. (1985),Appl. Biochem. Biotechnol. 11, 433–443.
Singh, A., Kumar, P. K. R., and Schugerl, K. (1991),Biotechnol. 18, 205–212.
Tanaka, M., Fukui, M., and Matsuno, R. (1988),Biotechnol. Bioeng. 32, 897–902.
Sinitsyn, A. P., Bungay, M. L., Clesceri, L. S., and Bungay, H. R. (1983),Appl. Biochem. Biotechnol. 8, 25–29.
Reese, E. T. (1980),J. Appl. Biochem. 2, 36–39.
Hogan, C. M. and Mes-Hartree, M. (1990),J. Ind. Microbio. 6, 253–262.
Ramos, L. P., Breuil, C. and Saddler, J. N. (1993),Enzyme Microb. Technol. 15, 19–25.
Wright, J. D., Power, A. J., and Douglas, L. J. (1986),Biotechnol. Bioeng. Symp. 17, 285–302.
Author information
Authors and Affiliations
Additional information
Names are necessary to report factually on available data; however, the USDA neither guarantees nor warrants the standard of the product, and the use of the name by USDA implies no approval of the product to the exclusion of others that may also be suitable.
Rights and permissions
About this article
Cite this article
Moniruzzaman, M., Dale, B.E., Hespell, R.B. et al. Enzymatic hydrolysis of high-moisture corn fiber pretreated by afex and recovery and recycling of the enzyme complex. Appl Biochem Biotechnol 67, 113–126 (1997). https://doi.org/10.1007/BF02787846
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02787846