Abstract
Physical, chemical and rheological properties of a polysaccharide produced by an isolate of Klebsiella oxytoca were characterized. Freeze dried samples of the polysaccharide were neutral and were completely soluble in water. Samples did not form gels even in the presence of salt treatments. The major monosaccharide constituents of the polysaccharide were rhamnose (37%, w/w) and glucose (34%, w/w). Residues of cellobiose were detected, suggesting that the polysaccharide had a cellulose backbone. The gum was more comparable to broth apparent viscosities of xanthan gum than to gellan gum. The K. oxytoca polysaccharide (KOP) produced high solution viscosity at low concentrations. At a gum concentration 0.5% (w/v), an apparent viscosity of 400 cP at 24 s-1 was obtained. Rheological behavior showed that the KOP formed non newtonian fluids, indicating that it is a pseudoplastic biopolymer. Although the KOP solutions displayed pseudoplastic behavior, increases in shearing time did not result in significant changes on the apparent viscosity. This indicated that the gum is neither thixotropic nor rheopectic. The conclusion reached about the potential application of the gum was that it could be suitable for use as a stabilizing or suspending agent rather than a gelling agent.
Original language | English |
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Number of pages | 9 |
Journal | African Journal of Biotechnology |
Publication status | Published - 2007 |
Open Access - Access Right Statement
© 2007 Academic Journals. This work is published under the terms of the Creative Commons Attribution License. This permits anyone to copy, distribute, transmit and adapt the work provided the original work and source is appropriately cited. http://creativecommons.org/licenses/by/3.0/Keywords
- Klebsiella oxytoca
- apparent viscosity
- microbial exopolysaccharides
- pseudoplasticity
- rhamnose
- rheology
- whey