Mulualem, Daniel Mehabie (2011) Antibiotic Production and Optimization of Culture Condition of Actinomycetes from some Soda Lakes of Ethiopia. Masters thesis, Addis Ababa University.
![[img]](http://thesisbank.jhia.ac.ke/style/images/fileicons/application_pdf.png) |
PDF (Antibiotic Production and Optimization of Culture Condition of Actinomycetes from some Soda Lakes of Ethiopia.)
Daniel, Mehabie Mulualem.pdf - Accepted Version Restricted to Repository staff only Download (1MB) | Request a copy |
Abstract
The demand for new antibiotics increased due to the misuse and over use of antibiotics in various sectors creating an evolutionary pressure and resulting in multi drug resistant strains which result in increment of morbidity and mortality in the world. The main objective of this study was to explore the potential of alkaliphilic actinomycetes isolated from three Ethiopian soda lakes. About 171 isolates were screened for antibiotic production using cell free culture supernatant taken from the submerged fermentation and ethyl acetate crude extract of the culture, of which 93.6% of them showed antibiotic activity with cell free culture supernatant and 76 % of them with crude ethyl acetate extract against the test microorganisms used. Based on broad spectrum activity, zone of inhibition obtained and their activity with the use of crude ethyl acetate extract, two isolates LCHACT17and LABACT21 were chosen for further characterization. Antibiotic production was favored when phosphate concentrations was 0.2 % for LCHACT 17 and for LABACT 21. Yeast extract and sodium nitrate (for LCHACT 17) and combination of casein and potassium nitrate (for LABACT 21) were suitable nitrogen sources for antibiotic production. From the carbon sources used soluble starch was the best carbon source for antibiotic production by LCHACT17 while sucrose was found to be preferred carbon source by LABACT 21. Similarly it was observed that 1% sodium chloride concentration was favorable for antibiotic production by both isolates and the pH parameter indicated that pH10 (for LABACT 21) and pH11 (for LCHACT17) were the optimum pH for antibiotic production. The cell free culture supernatant of both isolates was stable at alkaline pH and decreases in activity at lower pH (pH 6 and below). The cell free culture supernatant of LCHACT17 was stable up to 60oc while LABACT 21 was stable up to 40 oc. The minimum inhibitory concentration (MIC) of LCHACT17 crude ethyl acetate extract against Streptococcus pneumonia was 12.5 mg/ml.
| Item Type: | Thesis (Masters) |
|---|---|
| Uncontrolled Keywords: | Alkaliphiles, Antibiotics, Disk diffusion |
| Subjects: | Q Science > Q Science (General) Q Science > QH Natural history > QH301 Biology Q Science > QK Botany S Agriculture > S Agriculture (General) T Technology > T Technology (General) |
| Divisions: | Africana |
| Depositing User: | Selom Ghislain |
| Date Deposited: | 25 Sep 2018 09:57 |
| Last Modified: | 25 Sep 2018 09:57 |
| URI: | http://thesisbank.jhia.ac.ke/id/eprint/5706 |
Actions (login required)
 |
View Item |