Abstract
Corn fiber is a coproduct produced during the corn wet-milling process and is similar to other high hemicellulose/cellulose-containing biomass such as grasses, straws, or bagasse, all of which represent potential fermentation feedstock for conversion into biofuels or other products. Corn fiber was subjected to ammonia-explosion (AFEX) treatment to increase degradability and then enzymatically digested with a combined mixture of commercial amylase, xylanase, and cellulase enzyme preparations. Whereas the starch and cellulose components were converted solely to glucose, oligosaccharides represented 30–40% of the xylan degradation products. This enzyme mixture also produced substantial oligosaccharides with xylans purified from corn fiber, corn germ, beechwood, oatspelt, or wheat germ. Commercial xylan-degrading enzyme preparations containing xylanase, xylosidase, and arabinosidase activities were then used alone or in varying combinations to attempt to maximize degradation of these isolated xylans of differing chemical compositions. The results showed that oatspelt and beechwood xylans were degraded most extensively (40–60%) with substantial amounts of xylose, xylobiose, and xylotriose as products depending on the enzyme combination used. Corn fiber and wheat germ xylans, which contain large amounts of arabinose and uronic acid sidechains, were poorly degraded and only small amounts of arabinose and xylose and large amounts of pentamer or longer oligosaccharides were produced by enzymatic degradation. The data suggest that whereas enzymatic digestion of biomass hemicellulose does not produce toxic products, the process is not effective in producing a suitable fermentable substrate stream because of the low levels of monosaccharides and high levels of oligosaccharides produced.
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References
Gulati, M., Kohlmann, K., Ladisch, M. R., Hespell, R. B., and Bothast, R. J. (1996),Bioresource Technol. submitted.
Dunning, J. W. and Lathrop, E. C. (1945),Indust. Eng. Chem. 37, 24.
Beall, D. S., Ingram, L. O., Ben-Bassat, A., Doran, J., Fowler, D. E., Hall, R. G., and Wood, B. E. (1992),Biotechnol. Lett. 14, 857.
Lawford, H. G. and Rousseau, J. D. (1992),Biotechnol. Lett. 14, 421.
Asghari, A., Bothast, R. J., Doran, J. B., and Ingram, L. O. (1995),J. Indust. Microbiol. 16, 42–47.
Grethlein, H. E. (1985),Bio. Technology 3, 155.
Torget, R. and Hsu, T.-A. (1994),Appl. Biochem. Biotechnol. 45/45, 5.
Carrasco, J. E., Saiz, M. C, Navarro, A., Soriano, P., Saez, F., and Martinez, J. M. (1994),Appl. Biochem. Biotechnol. 45/46, 23.
De La Rosa, L. B., Reshamwala, S., Latimer, V. M, Shawky, B. T., Dale, B., and Stuart, E. D. (1994),Appl. Biochem. Biotechnol. 45/46, 483.
Moniruzzaman, M., Dale, B. E., Hespell, R. B., and Bothast, R. J. (1996),Appl. Biochem. Biotechnol. submitted.
Pettersson, G. and Porath, J. (1966),Methods Enzmol. 8, 603.
Cotta, M. A. (1993),Appl. Environ. Microbiol. 59, 3557.
York, W. S., Darvill, G., McNeil, M., Stevenson, T. T., and Albersheim, P. (1986),Methods Enzymol. 118, 1.
Hespell, R. B. (1992),Curr. Microbiol. 25, 189.
Hespell, R. B. and Whitehead, T. R. (1990),J. Dairy Sci. 73, 3013.
Lowry, O. H., Rosebrough, N. J., Farr, A. L., and Randalt, R. J. (1951),J. Biol. Chem. 193, 265.
Hespell, R. B. and Cotta, M. A. (1995),Appl. Environ. Microbiol. 61, 3042.
Dehority, B. A. (1967),Appl. Microbiol. 15, 987.
Montgomery, R. and Smith, (1970),J. Am. Chem. Soc. 79, 695.
DeBeire, P., Preim, B., Strecker, G., and Vigon, M. (1990),Eur. J. Biochem. 187, 573.
Greve, L. C, Labavitch, J. M., and Hungate, R. E. (1984),Appl. Environ. Microbiol. 47, 1135.
Lee, S. F. and Forsberg, C. W. (1987),Can. J. Microbiol. 33, 1011.
Nishitani, K. and Nevins, D. J. (1991),J. Biol. Chem. 266, 6539.
Wiikari, L., Kantelinen, A., Buchert, J., and Puls, J. (1994),Appl. Microbiol. Biotechnol. 41, 124.
Kormelink, F. J. M. and Voragen, A. G. J. (1993),Appl. Microbiol. Biotechnol. 38, 688.
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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.
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Hespell, R.B., O’Bryan, P.J., Moniruzzaman, M. et al. Hydrolysis by commercial enzyme mixtures of AFEX-treated corn fiber and isolated xylans. Appl Biochem Biotechnol 62, 87–97 (1997). https://doi.org/10.1007/BF02787986
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DOI: https://doi.org/10.1007/BF02787986