Alginates are copolymers of &beta / -D-mannuronic (M) and &alpha / -L-guluronic acids (G). In this study, Azotobacter vinelandii ATCC® / 9046 was used to produce alginate in a fermentor. The effect of parameters such as dissolved oxygen tension (DOT), agitation speed, initial concentrations of sucrose and calcium
on the properties of alginate were examined. Changes of DOT in the range of 1 and 10 % affected alginate production. The optimum DOT giving high alginate yield (4.51 g/L) and maximum viscosity was observed as 5 % yielding moderate GG-blocks of 55 %. Both high and low agitation levels reduced alginate production, but these conditions increased GG-block alginates as 76 and 87 % at 200 and 700 rpm, respectively. Moderate
sucrose and calcium concentrations, 20 g/L and 50 mg/L, respectively were found better since further increase in their concentrations did not lead to a considerable improvement in alginate production and quality. Sodium alginates produced in this work were investigated for maximum heavy metal uptake with a special focus on copper ion and the highest copper uptake was around 1.9 mM Cu2+/g alginate. Findings showed that the block distribution of alginate was not as important as expected for copper removal. Alginate together with calcium ions was used for the removal of turbidity. The amount of GG-block was found to be important in turbidity removal. Alginate having 55 % GG block and 8.9 cP viscosity resulted in a final turbidity lower than 1 NTU at 2 mg/L of alginate with 60 mg/L of calcium ion.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12612919/index.pdf |
| Date | 01 January 2011 |
| Creators | Moral, Cigdem |
| Contributors | Sanin, Dilek F. |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for METU campus |
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