Ethanol production by mixed-cultures ofPaenibacillus sp. andZymomonas mobilis using the raw starchy material from sweet potato
- 175 Downloads
The conversion of raw starchy materials from sweet potato into ethanol in a mixed-culture of an amylolytic bacterium, Paenibacillus sp. and different strains of Zymomonas mobilis were studied. Raw starchy material from sweet potato was hydrolyzed by Paenibacillus sp. to glucose, which is directly used by Z. mobilis for ethanol production. A mixed-culture of Z. mobilis ATCC 29191 and Paenibacillus sp. 9 yielded the highest ethanol concentration (6.89 g/l) in cultures of small volumes. The effects of medium pH (the best pH value were between 5.0 and 6.0) and the supplementation of the medium with glucose on ethanol production were also studied. In a large-scale fermentation, the final concentration of ethanol was 6.60 g/l, which corresponds to 23.24% of the theoretical yield of the ethanol from 50.0 g/l of the starch from raw sweet potato after a 120 h fermentation period.
Key wordsbioethanol mixed-culture Paenibacillus sp. sweet potato starch Zymomonas mobilis.
Unable to display preview. Download preview PDF.
- Altintas M.M., Ulgen K.O., Kirdar B., Onsan Z., Oliver S.G. (2002). Improvement of ethanol production from starch by recombinant yeast through manipulation of environmental factors. Biotechnol. Bioeng., 31: 640–647.Google Scholar
- Budi S.W., Tuinen D. van., Arnould C., Dumas-Gaudot E., Gianinazzi-Pearson V., Gianinazzi S. (2000). Hydrolytic enzyme activity ofPaenibacillus sp. strain B2 and effects of the antagonistic bacterium on cell integrity of two soil-borne pathogenic fungi. Appl. Soil Ecol., 15: 191–199.CrossRefGoogle Scholar
- Chandel A.K., Chan E., Rudravaram R., Narasu L.M.L., Rao L.V., Ravindra P. (2007). Economics and environmental impact of bioethanol production technologies: an appraisal. Biotechnol. Mol. Biol. Rev., 2: 14–32.Google Scholar
- Comis D. (2008). Agriculture Research Service USDA. Sweet potato out-yields corn in ethanol production study, http://www.ars.usda.gov/is/pr/2008/080820.htm> Google Scholar
- Hoshino K., Tanikuchi M., Marumoto H., Fujii M. (1989). Repeated batch conversion of raw starch to ethanol using amylase immobilized on a reversible soluble-autoprecipitating carrier and flocculating yeast cells. Agric. Biol. Chem., 53: 1961–1967.Google Scholar
- Huang J., Song J., Qiao F., Keith O.F. (2003). Sweet Potato in China: Economic Aspects and Utilization in Pig Production. International Potato Center (CIP), Bogor, Indonesia.Google Scholar
- Rogers P.L., Jeon Y.J., Lee K.J., Lawford H.G. (2007).Zymomonas mobilis for fuel ethanol and higher value products. Adv. Biochem. Eng./Biotechnol., DOI 10.1007/10_2007_060.Google Scholar
- Schwartz L (2008). China fuels ethanol industry with yams, sweet potatoes and cassava. http://www.renewableen-ergyworld.com/rea/news/story?id=52450.Google Scholar