The inulin neoseries, trisaccharide, neokestose was produced by the yeast
Xanthophyllomyces dendrorhous (Phaffia rhodozyma Y4-3) during growth on
sucrose. To produce neokestose, whole cells harvested from the late
exponential growth phase were incubated for 36 to 40 h at 25 oC in 0.2 M citratephosphate
buffer (pH 7) containing 220 g.l-1 sucrose. Neokestose made up
about 50 % of this mixture, which was purified equally well by both a
carbon:celite chromatography as well as a batch filtration process, when eluting
with similar amounts of water followed by a 50 % ethanol elution step. A final
product was combined from various purification runs which consisted of 82.6 %
neokestose, 8.7 % sucrose, 7.6 % GF3, 1.2 % glucose and 0.1 % fructose.
Lactobacillus and Bifidobacterium genera are considered part of the beneficial
group in in the intestine of animal and man. Bifidobacterium levels were higher
than Lactobacillus levels in the caeca of New Hampshire layers, whereas in this
study only Lactobacillus species were found in broilers. The reason for the
absence of the Bifidobacterium species in the caecum of broilers was not
determined. The prebiotic effect was evaluated on 5 week old broiler caecal
material in vitro over 24 hours based on the viable levels of the total anaerobic
bacteria, Lactobacillus and coliforms. The prebiotic effect was also evaluated on
viable levels of added Salmonella Typhi, Escherichia coli and Campylobacter
jejuni. Volatile fatty acids and pH were measured. The effect of neokestose on
these groups was compared to that of inulin, a known prebiotic, and glucose.
The total anaerobe and Lactobacillus levels increased over 24 hours for
neokestose, inulin and glucose. Although there was no significant difference
between the treatments higher levels were found for neokestose and glucose
than for inulin. A decrease in the viable levels of E. coli, S. Typhi and C. jejuni
were seen over 24 hours. The production of acetic acid, butyric acid and
propionic acid was not significantly different for the treatments and the control.
The pH decrease over 24 hours for the treatments was significantly different from
the control, which indicated that lactate (not measured) production was probably
higher in the neokestose, inulin and glucose treatments. In vivo tests are, however, required to fully evaluate the prebiotic and âbifidogenicâ effect of neokestose for broilers.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ufs/oai:etd.uovs.ac.za:etd-06242008-095140 |
| Date | 24 June 2008 |
| Creators | van der Westhuizen, René Johan |
| Contributors | Prof RR Bragg, Prof SG Kilian |
| Publisher | University of the Free State |
| Source Sets | South African National ETD Portal |
| Language | en-uk |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.uovs.ac.za//theses/available/etd-06242008-095140/restricted/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University Free State or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
Page generated in 0.0025 seconds