|Leathers, Timothy - Tim|
Submitted to: Cereal Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/27/2002
Publication Date: 12/1/2003
Citation: BIELY, P., AHLGREN, J.A., LEATHERS, T.D., GREENE, R.V., COTTA, M.A. ARYL-GLYCOSIDASE ACTIVITIES IN GERMINATING MAIZE. CEREAL CHEMISTRY. 2003. V. 80. P. 144-147. Interpretive Summary: Practical new methods are needed to produce fermentable sugars from low-value agricultural residues such as corn fiber. Because corn fiber is recalcitrant to digestion by microbial enzymes, we examined for the first time enzymes from maize itself for their ability to attack corn fiber components. This work will be of interest to researchers developing new uses and value-added products from agricultural commodities and byproducts
Technical Abstract: Soluble protein extracts of germinating maize seedlings exhibited a limited ability to hydrolyze purified xylans, and specific assays were unable to confirm the presence of endo-beta-1,4-xylanase activity. However, extracts contained a variety of aryl-glycosidase activities, including beta-glucosidase, beta-xylosidase, and alpha-L-arabinofuranosidase. These activities peaked in 3-4 day seedlings and were particularly concentrated in shoot and root tissues. Maximal levels of beta-glucosidase were two orders of magnitude greater than those of beta-xylosidase or alpha-L-arabinofuranosidase. Isoelectric focusing gels revealed multiple forms of these enzymes. The principal beta-glucosidase and alpha-L-arabinofuranosidase protein species were clustered at pI 4.8-4.9 and pI 5.8-6.0, respectively. Beta-xylosidase activity appeared to be associated with both of these enzymes, and no evidence was obtained for a distinct beta-xylosidase. Qualitative assays indicated the presence of feruloyl esterase activity.