| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 177.73 KB | Adobe PDF |
Advisor(s)
Abstract(s)
Production of lactan, a polysaccharide composed of mannose, galactose and galacturonic acid (at the ratio of 5:3:2), starting from a semidefined
medium containing lactose via fermentation with Rahnella aquatilis was described previously. In this communication, such polysaccharide
was produced from five alternative fermentation media: (1) a synthetic (defined) medium, plain whey (under (2) aerobic and (3)
anaerobic conditions), (4) whey permeate and (5) whey with 2% NaCl (w/v). The effect of the concentration of polysaccharide, pH and ionic
strength at harvest on the rheological properties of the polysaccharide was studied using lactan-enriched fractions recovered from each
medium and analysed in solution under steady shear flow. Lactan solutions showed a shear-thinning behaviour in all cases, and increases in
viscosity were observed at increasing concentrations of polysaccharide, as expected. The polysaccharide fraction produced from whey with
2% (w/v) NaCl and plain whey under anaerobic conditions exhibited lower viscosity than that produced from the other media, an observation
that is associated with the lower concentration of polysaccharide. Post-harvest addition of salts (KCl or CaCl2) and changes in pH (3–11)
affected slightly the viscosity of the polysaccharide solutions. q1998
Description
Keywords
Lactan Rahnella aquatilis Polysaccharide
Citation
PINTADO, M. E....[et al] - Rheological characterization under shear of a fraction of polymer produced via fermentation of whey-related media by Rahnella aquatilis. Carbohydrate Polymers. ISSN 0144–8617. Vol. 37 (1998), p. 1–6
Publisher
Elsevier