Calorilvietric Investigation of the Action of Propolis on Bacterial Growth and Metabolism
| dc.contributor.advisor | Lamprecht, L. (Professor) | |
| dc.contributor.author | Garedew, Assegid | |
| dc.date.accessioned | 2018-06-21T12:12:18Z | |
| dc.date.accessioned | 2023-11-08T16:33:30Z | |
| dc.date.available | 2018-06-21T12:12:18Z | |
| dc.date.available | 2023-11-08T16:33:30Z | |
| dc.date.issued | 1996-06 | |
| dc.description.abstract | Power-time (P-t) curves were established by growing Micrococcus /uteus in a flow calorimetric system using different inoculum densities to see if inoculum size affects calorimetric experiments. The P-t curves obtained for the lower inoculum densities used were the same in several aspects except length of the calorimetric lag phase. Spectrophotometric and polarographic experiments were done simultaneously with the calorimetric experiments to see if results from the latter are true pictures of metabolic events in the fermenter or experimental artifacts introduced due to separation of fermenter from the calorimeter. Results from experiments with the different methods showed the same pattern indicating that separation of fermenter from the calorimeter does not introduce error at the pumping rate used (100 mL 11• 1). Extraction of propolis was done with 70% methanol as a solvent. The yield of extraction was 21 % (w/w) for all propolis samples used. Addition of water to the ethanol solution of extract of propolis (EEP) resulted in precipitation of the water insoluble components and hence separation of the water soluble from the water insoluble components. The proportion of water soluble components was very low in propolis sample 3 (prop3). Calorimetric experiments with propolis were done by incorporating increasing concentrations of tincture at different phases of the P-t cun•e and different propolis samples at the mid exponential phase of the P-t curve for comparison of their effect. It was found that effect of propolis can be detected at all phases of growth. However, comparison of antibacterial activities for the different concentrations of propolis used was not possible at the lag phase. Variation in activity was observed among the different propolis samples in their effect on the drop of the P-t curve which is directly proportional to the amount of cells killed or inactivated, and the time needed for the resumption of growth after the curve has fallen off to a minimum value. Though incorporation of tincture resulted in a drop of the P-t curve comparable to other propolis samples, growth was resumed sooner suggesting lower inhibitory effect on the survivors. But propolis sample 2 (prop2) possesses higher killing and inhibitory effect on the survivors. For all propolis samples used the strength of antibacterial activity, based on drop of the P-t curve and subsequent effect. could be ordered as follows: EEP > water insoluble component > water soluble component. For some propolis samples the effect of EEP was greater than even the sum of two of its components at a ce11ain concentration. It was therefore deduced that the water soluble and insoluble components exhibit synergistic interactions in EEP. The calorimetric method was found out to be slightly less sensitive to detect effect of lower concentrations of propolis than the agar well diffusion assay method. However, the fom1er method had a very short assay time and clearly demonstrated that the mechanism of action of propolis is bactericidic. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/2701 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Biology | en_US |
| dc.title | Calorilvietric Investigation of the Action of Propolis on Bacterial Growth and Metabolism | en_US |
| dc.type | Thesis | en_US |