title: Enzymatic modification of schizophyllan.
abstract: An enzymatic method was developed for the progressive modification of the polysaccharide schizophyllan. Fungal strains Hypocrea nigricans NRRL 62555, Penicillium crustosum NRRL 62558, and Penicillium simplicissimum NRRL 62550 were previously identified as novel sources of β-endoglucanase with specificity towards schizophyllan. Concentrated enzyme preparations from these strains showed specific activities of 1.7-4.3 U β-glucanase/mg protein. Using dilutions of these enzymes in time course digestions, schizophyllan was progressively modified to reduced molecular weight species. Glucose and oligosaccharides were found only in the more complete digestions, and thus modified schizophyllan can be produced quantitatively, without loss, to small molecules. Permethylation analysis confirmed that modified schizophyllan retains the fundamental linkage structure of native schizophyllan. Modified schizophyllan species showed progressively reduced viscosity profiles, and all exhibited pseudoplasticity in response to shear thinning.
authors.affiliation: Renewable Product Technology Research Unit, National Center for Agricultural Utilization Research, Agricultural Research Service, U.S. Department of Agriculture, 1815 North University Street, Peoria, IL, 61604, USA, tim.leathers@ars.usda.gov.
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Leathers
authors.forename: Nongnuch
authors.initials: N
authors.lastname: Sutivisedsak
authors.forename: Melinda S
authors.initials: MS
authors.lastname: Nunnally
authors.forename: Neil P J
authors.initials: NP
authors.lastname: Price
authors.forename: April M
authors.initials: AM
authors.lastname: Stanley
mesh_terms: D001711:Biotransformation; D005959:Glucosidases / Q000378:metabolism*; D007700:Kinetics; D010407:Penicillium / Q000201:enzymology*; D012566:Sizofiran / Q000378:metabolism*; D013997:Time Factors; D014242:Trichoderma / Q000201:enzymology*
chemical_list: D012566:Sizofiran; D005959:Glucosidases