NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Rheologically interesting polysaccharides from yeastsWe have examined the relationships between primary, secondary, and tertiary structures of polysaccharides exhibiting the rheological property of friction (drag) reduction in turbulent flows. We found an example of an exopolysaccharide from the yeast Cryptococcus laurentii that possessed high molecular weight but exhibited lower than expected drag reducing activity. Earlier correlations by Hoyt showing that beta 1 --> 3, beta 2 --> 4, and alpha 1 --> 3 linkages in polysaccharides favored drag reduction were expanded to include correlations to secondary structure. The effect of sidechains in a series of gellan gums was shown to be related to sidechain length and position. Disruption of secondary structure in drag reducing polysaccharides reduced drag reducing activity for some but not all exopolysaccharides. The polymer from C. laurentii was shown to be more stable than xanthan gum and other exopolysaccharides under the most vigorous of denaturing conditions. We also showed a direct relationship between extensional viscosity measurements and the drag reducing coefficient for four exopolysaccharides.
Document ID
20040089247
Document Type
Reprint (Version printed in journal)
Authors
Petersen, G. R. (Jet Propulsion Lab., California Inst. of Tech. Pasadena CA United States)
Nelson, G. A.
Cathey, C. A.
Fuller, G. G.
Date Acquired
August 21, 2013
Publication Date
January 1, 1989
Publication Information
Publication: Applied biochemistry and biotechnology
Volume: 20-21
ISSN: 0273-2289
Subject Category
Life Sciences (General)
Funding Number(s)
CONTRACT_GRANT: 4-595
Distribution Limits
Public
Copyright
Other