Enzymic dissociation of zea shoot cell wall polysaccharides : I. Preliminary characterization of the water-insoluble fraction of zea shoot cell walls

Abstract

The water-insoluble fraction, obtained after successive treatment of an insoluble fraction of a buffer-homogenate of Zea mays L. hybrid B73 x Mo 17 shoots with 3 molar LiCl and hot water, was treated with alpha-amylase to remove starch. This fraction has been subjected to sugar composition analysis and the major glycosidic linkages were determined. The results suggest that the water-insoluble fraction is mainly composed of arabinoxylan, (1 --> 3), (1 --> 4-)-beta-d-glucan, xyloglucan, (1 --> 4)-galactan, polygalacturonic acid, and cellulose. The insoluble fraction also contained ferulic acid (about 440 micrograms per 50 milligrams dry weight), which was released from the fraction by treatment with aqueous NaOH.Novo Ban 120 from Bacillus subtilis was found to be an appropriate enzyme source for selective dissociation of Zea shoot wall polysaccharides.