Back to Search
Start Over
Tandem production of levan and ethanol by microbial fermentation.
- Source :
-
Green Chemistry . Jul2010, Vol. 12 Issue 7, p1242-1247. 6p. - Publication Year :
- 2010
-
Abstract
- Tandem production of levan and ethanol by microbial fermentation using sucrose substrate was investigated. The tandem process involves fermentation of Bacillus subtilis(natto) Takahashi in a sucrose medium to produce levan, separation of the levan product from glucose by-product by ultrafiltration and fermentation of the glucose remnant from levan production by Zymomonas mobilisto produce ethanol. After cultivation of B. subtilis(natto) Takahashi for 48 h, 56.0 ± 0.6 g l−1of levan was produced in a medium containing 250 g l−1sucrose, which was 45 ± 0.5% yield on available fructose. After removing the cells, the fermentation broth was concentrated by ultrafiltration through a membrane of 5 kDa cutoff. The filtrate which contained 179 ± 3 g l−1of hexose was diluted, supplemented with yeast extract (5 g l−1), (NH4)2SO4(1 g l−1), MgSO4·7H2O (0.5 g l−1), KH2PO4(1 g l−1) and used for alcohol fermentation by Z. mobilis. Incubation of Z. mobilisin the medium containing glucose remnant at 30 °C, pH 5.5, 175 rpm for 120 h gave from 21.1 ± 0.3 to 26.5 ± 0.2 g l−1of bio-ethanol depending on the dilution. The tandem process developed in this study is an eco-friendly process in that the sucrose substrate was fully utilized without wasting any by-products in the process; in addition, two invaluable environmentally-friendly biomaterials (levan and ethanol) were produced. Furthermore, the amount of alcohol required for levan recovery could be reduced to a quarter of that generally used in the conventional precipitation. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14639262
- Volume :
- 12
- Issue :
- 7
- Database :
- Academic Search Index
- Journal :
- Green Chemistry
- Publication Type :
- Academic Journal
- Accession number :
- 51995429
- Full Text :
- https://doi.org/10.1039/b924765c