Production of Ethanol Fromcane Molasses by Using Awild Yeast And Brewery Yeast
| dc.contributor.advisor | Gessesse, Amare (PhD) | |
| dc.contributor.author | Mama, Ebrahim | |
| dc.date.accessioned | 2019-11-08T08:30:12Z | |
| dc.date.accessioned | 2023-11-08T16:39:18Z | |
| dc.date.available | 2019-11-08T08:30:12Z | |
| dc.date.available | 2023-11-08T16:39:18Z | |
| dc.date.issued | 2008-07-04 | |
| dc.description.abstract | A fermenting isolate TAYI 4-2 and brewer yeast were utilized for alcoholic fermentation using sugarcane molasses. The fermentation of molasses was optimized with respect to temperature, pH and sugar concentration. Results revealed a pH 4.5 and 11% sugar concentration as optimum for fermentation for both microorganisms studied. The optimum temperature for TAYI 4-2 was 350C while for brewer yeast 30 0C. Under optimized conditions, TAYI 4-2 and brewer yeast produce 50.50 and 48.76 g/l of ethanol, respectively. The time required to produce a maximum alcohol by TAYI4-2 was around 54h and productivity was limited to 1.04 g/l/h. In order to improve the productivity, the immobilization of TAYI 4-2 was simply performed by the enriched cells cultured media harvested at exponential growth phase. Immobilization of yeast cells was carried out by entrapment in 2% calcium alginate and tested for ethanol production. In a batch culture of immobilized cells, the ethanol productivity was improved to 2.12 g/l/h. To further optimize productivity, the immobilized TAYI 4-2 was loaded continuous immobilized cell reactor (ICR). The performance of continuous fermentation system using immobilized TAYI 4-2 in ICR was evaluated in terms of ethanol productivity and fermentation efficiency with varying sugar concentration in the medium, at different initial pH and dilution rate. Ethanol productivity was higher at 11% initial sugar concentration similar to batch fermentation but the productivity was improved to 14.34 g/l/h. High ethanol productivity was achieved with a medium containing 11%( w/v ) total sugar concentration at a dilution rate of 0.15 h.1. And it was found that an increase in dilution rate from 0.15 h.1 to 0.25 h.1 resulted in lowering ethanol concentration in the fermented broth. The dilution rate increased the amount of sugar un-utilized found to increase. The high speed through the continuous system which cause a short residence time in the fermenter which may leads sugars in the medium to pass un-fermented and cause declining in fermentation efficiency. On the basis of the results obtained ,the potential yeast isolate TAYI 4-2 screened from .tella. showed the highest fermentation efficiency and productivity when immobilized in continuous system of fermentation within short period of time. This clearly indicates potential ethnologic microbe from .tella. was highly effective when it is immobilised and run in continuous system of fermentation at its optimum physico-chemical conditions. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/123456789/20044 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Brewer Yeast | en_US |
| dc.subject | Cane Molasses | en_US |
| dc.subject | Ethanol | en_US |
| dc.subject | Immobilized Cells | en_US |
| dc.title | Production of Ethanol Fromcane Molasses by Using Awild Yeast And Brewery Yeast | en_US |
| dc.type | Thesis | en_US |