Evaluation of different types of active charcoal in the treatment of the hemicellulose hydrolysate from sugarcane bagasse for the biotechnological production of xylitol

• Grant number: 00/14008-3
• Support Opportunities: Regular Research Grants
• Duration: March 01, 2001 - February 28, 2003
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Maria das Graças de Almeida Felipe
• Grantee: Maria das Graças de Almeida Felipe
• Host Institution: Faculdade de Engenharia Química de Lorena (FAENQUIL). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). Lorena , SP, Brazil

Abstract

The number of research projects on the development of a technology with a view to the biotechnological exploitation of sugarcane bagasse hydrolysate for the production of xylitol is increasing every day. This facts due principally to the peculiarities of xylitol as a non-cariogenic sweetener, for diabetics, obese people and recently as an aid in the treatment of osteoporosis, in addition to this alternative technology contributing to a reduction in the environmental impact caused by sugarcane bagasse. This study will evaluate different treatment of hemicellulose hydrolysate of sugarcane bagasse with active charcoal to minimize the toxicity of the hydrolysate, aiming for improvement in the bioconversion xylose to xylitol through Candida quilliermondii. The hydrolysate obtained by acid hydrolysis will be treated by the technique of alteration of its acid pH combined with the adsorption with active charcoal and immediately this will be supplemented with nutrients. Fermentations will be carried out with hydrolysates treated with different types of active charcoal, given that the efficiency of the treatment is dependent on the adsorption activity, the potential of which is related to the physico-chemical properties of the active charcoal and the conditions employed during the treatment. After the choice of the type of charcoal, studies will be carried out to establish the parameters of adsorption: temperature, contact time, agitation, pH and concentration of charcoal, with the hydrolysates being used for the fermentations. The trials will be conducted in Erlenmeyer flasks in a rotary shaker. Analyses will be undertaken regarding the composition of the hydrolysates, the reduction in the concentration of the toxic compounds such as acetic acid, phenolic compounds, furfural and hydroxymethylfurfural, pH, the consumption of sugars, formation of xylitol and cells, as well as variation in the pH of the fermentation. The concentration of sugars and toxic compounds will be determined by liquid chromatography and cellular growth will be analyzed by spectrophotometry and/or cell count in Neubauer chamber. The trials will conform to fractional factorial design 25-1. (AU)