Pectinase from Bacillus Subtilis Strain Btk27: Optimization of Cultural Conditions, Characterization of the Enzyme and its Potential Application in Coffee Processing
| dc.contributor.advisor | Abate Dawit (PhD) | |
| dc.contributor.author | Jeilu Oliyad | |
| dc.date.accessioned | 2018-06-18T06:58:24Z | |
| dc.date.accessioned | 2023-11-18T09:50:12Z | |
| dc.date.available | 2018-06-18T06:58:24Z | |
| dc.date.available | 2023-11-18T09:50:12Z | |
| dc.date.issued | 2015-03 | |
| dc.description.abstract | The demand for enzymes in the global market is projected to rise at a fast pace in recent years. There has been a great increase in industrial applications of pectinase owing to their significant biotechnological uses. For this reason, this study was undertaken with aims of; isolating and screening microorganisms from coffee pulp, molecular identification of the potential pectinolytic isolates and optimizing pectinase production both on submerged fermentation and solid state fermentation. Moreover, characterizing the enzyme and proving its potential application in demucilisation of coffee. In the present investigation 95 isolates were isolated and screened for their pectinolytic activity from coffee pulp samples. The isolates with high potential pectinase activity were identified molecularly by sequencing 16s rDNA region of the isolates. The bacterium, Bacillus subtilis strain Btk27 was selected for production optimization of the enzyme based on its outstanding features. The production of pectinase was enhanced by 656% (in YEP) and 159% (in wheat bran) times on submerged fermentation and solid state fermentation, respectively. In addition, optimization steps were carried out to make the production of pectinase enzyme cost effective and commercially viable. The maximum pectinase production was observed using YEP (submerged fermentation) and Wheat bran (solid state fermentation) at initial pH of 6.5, at 370C and by supplementing the medium with 3mM MgSO4.7H2O. The maximum Pectinase activity was achieved at pH 7.5 and 500C. Also, the enzyme activity was found stimulated with Mg2+ and Ca2+ metal ions. Moreover, it was stable on EDTA, Trixton-100, Tween 80 and Tween 20. The enzyme, Km and Vmax values were identified as 1.879mg/ml and 149.6 U respectively. The potential application of the enzyme for coffee processing was studied, and it is found that complete removal of mucilage from coffee beans within 24 hours of treatment indicating the potential application in coffee processing. Keyword: Coffee pulp; Coffee processing; Bacillus subtilis strain Btk27; Microbial Pectinase, Submerged fermentation ; Solid state fermentation | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/1140 | |
| dc.language.iso | en | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Coffee pulp; Coffee processing; Bacillus subtilis strain Btk27; Microbial Pectinase, Submerged fermentation ; Solid state fermentation | en_US |
| dc.title | Pectinase from Bacillus Subtilis Strain Btk27: Optimization of Cultural Conditions, Characterization of the Enzyme and its Potential Application in Coffee Processing | en_US |
| dc.type | Thesis | en_US |