Optimization of detoxification treatment conditions of the rice straw hemicellulosic hydrolysate by advanced oxidative processes aiming to ethanol producing by Pichia stipitis

• Grant number: 11/19031-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): December 01, 2011
• Effective date (End): July 31, 2013
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Ines Conceicao Roberto
• Grantee: João Paulo Alves Silva
• Host Institution: Escola de Engenharia de Lorena (EEL). Universidade de São Paulo (USP). Lorena , SP, Brazil

Abstract

This project aims at optimizing and scaling up of treatment for detoxification of rice straw hemicellulosic hydrolysate by advanced oxidative processes (AOPs), to its use as a culture medium for ethanol production by yeast Pichia stipitis NRRL Y- 7124. In the first stage a 23 factorial design will be used to evaluate the influence of the concentration of O3, H2O2 and initial pH on the reduction of toxic compounds present in the hydrolysate and the impact of this reduction on the fermentability of the medium. Detoxification treatments will be conducted in glass reactor with capacity of 150 ml, equipped with agitation, gas input (for introduction of ozone) and jacketed vessel for temperature control. Based on the results of the experimental design, additional tests may be performed to establish the optimal conditions for detoxification treatment. In the second stage the influence of scaling up on the efficiency of detoxification of the hydrolysate by AOPs will be assessed at conditions previously established. At this stage, the experiments will be performed in the reactor with about ten times the volume of the reactor used in the study of optimization. After the definition of treatment conditions on a larger scale, fermentation tests will be carried out with yeast Pichia stipitis to monitor the kinetic profile of ethanol production in detoxified hydrolysate. This proposal is part of the research program of the Group of Applied Microbiology and Biomass Conversion, Department of Industrial Biotechnology (LOT) of the Engineering School of Lorena, University of São Paulo (USP-EEL), which aims to develop technology for the use of lignocellulosic materials, especially the agro-industrial waste, aiming at the production of inputs by means of biotechnological processes. (AU)