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Use of alternative regional substrates for the production of ethanol, levan and sorbitol by Zymomonas mobilis

Grant number: 06/54750-7
Support type:Regular Research Grants
Duration: August 01, 2006 - July 31, 2008
Field of knowledge:Agronomical Sciences - Food Science and Technology
Principal Investigator:Crispin Humberto Garcia Cruz
Grantee:Crispin Humberto Garcia Cruz
Home Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil


The principal product of the fermentation of sugars by Zymomonas mobilis is ethanol when glucose and fructose are used as carbon sources. However, when sucrose is used, the yield of ethanol decreases owing to the formation of economically important subproducts such as levan and sorbitol. The use of low cost, alternative regional substrates to obtain these bio-products has become very interesting, since, in addition to the ease of acquisition and the low cost, the products to be obtained have a high added value. The principal objective of this work will be to study the production process of ethanol, of exopolysaccharide levan and of sorbitol by Zymomonas mobilis CCT 4494, using commercial sucrose, sugarcane juice and molasses. In addition, evaluation will also be undertaken of the activity of the levansucrase enzyme, aiming, subsequently, for its individual use. Tests will be conducted on the effect of the addition of different concentrations of sucrose, mineral salts (KCl, K2SO4; MoSO4 and CaCl2) in the production media, as well as the influence of the incubation temperature and the initial pH. (AU)