Aerobic Heterotrophic Bacterial Flor1ff one of Shalla Hot Springs
| dc.contributor.advisor | Abegaz Berhanu (PhD) | |
| dc.contributor.author | Kibret Mulugeta | |
| dc.date.accessioned | 2018-07-06T13:11:01Z | |
| dc.date.accessioned | 2023-11-08T16:32:53Z | |
| dc.date.available | 2018-07-06T13:11:01Z | |
| dc.date.available | 2023-11-08T16:32:53Z | |
| dc.date.issued | 1991-06 | |
| dc.description.abstract | Four sites in one of the hot springs of Shalla were selected for the study. The water from the sites merge to form a stream lqhich forms a temperature gradient. In this sttldy four' media were compared for the cuI ti vation and isolation of aerobic heterotrophic bacteria. The pH of the hot spring was 8.7 with a temperature of 96-560C. The formulated media were adjusted to pH values of 7.0-13.0. However,high counts of bacteria (lxl03-7xl01 cfu/ml) was only registered when the pH lqas adjusted between 8.0 and 9.0. A medium containing normal concentration of Trypton Soya Agar (TSA) was effective in supporting the growth of bacteria than a medium containing onequarter strength of TSA or supplement of tl'ace minerals. Replacing trace minerals ld th hot spring water improved the total number of bacteria growing and also the number of isolates. Thermophiles were numerous (lxl03-7xl01 cfu/ml) than thermotolerants (2xl02-2xlOI cfu/ml) at all si tes. The population of Bacillus brevis, Bacillus sphaericus, Bacillus stearothermophilus and Hicrococcus sp. was found to be low at lOlqer environmental temperatures than at higher environmental temperatures. In the course of this study a total of 44 microorganisms were isolated and characterized. Twenty nine were identified. to the species level and were found to be members of genus Bacillus. Three isolates were Gr~n-positive cocci identified to the genus level - Micrococcus. The remaining 12 isolates were either Gram-positive, filamentous or non-filamentous rods which need a detailed biochemical analysis for identification. To identify if any of the isolates may have industrial applications, they were checked for production of amylase and protease. Fifteen of the isolates produced protease, 18 amylase and eleven produced both amylase and protease. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/7112 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Biology | en_US |
| dc.title | Aerobic Heterotrophic Bacterial Flor1ff one of Shalla Hot Springs | en_US |
| dc.type | Thesis | en_US |