Construction of Trichoderma reesei ace1/cre1-delta mutant strain, optimization of cellulase production in bioreactors for sugarcane bagasse enzymatic hydrolysis

• Grant number: 12/19751-3
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: January 01, 2013
• End date: February 28, 2014
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Jose Geraldo da Cruz Pradella
• Grantee: Alexandre Maller
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

The obtaining of enzymes with desirable physic-chemical characteristics at low cost is one of the major challenges in the biofuel research. Thus, the hydrolytic enzymes production by Trichoderma reesei mutant strains has been attracting interest in the industry sector. This microorganism has three positive activators (XYR1, ACE2 and HAP2/3/5 complex) and two repressors (ACE1 and CRE1) which are involved in cellulases transcriptional regulation. The deletion of both repressors was not performed in the same strain. This would increase significantly the production of these enzymes in large scale bioreactors. Biological reactors were used commonly to produce a lot of several compounds, as proteins or secondary metabolites. Biological reactors are commonly used to produce large amount of interest compounds in industrial scale, as proteins or secondary metabolites. The efficiency of these devices is affected by several factors, as kind of reactor, production scale, air rate, agitation, temperature and pH. So, the standardization of these parameters is needed to optimize a bioprocess. The sugar cane industry generates a large amount of biomass waste on São Paulo State. So, the research to find new systems of enzymatic production is necessary to recycling these organic materials in the biofuel production. The aims of this work are constructing of Trichoderma reesei ace1/cre1 mutant strain with high secretion of cellulases and hemicellulases, scaling-up of enzymatic production and optimizing of the sugar cane biomass degradation in bioreactors. Thus, the project intends to apply enzymes in the biofuel industry. In conclusion, the results go to provide microorganism mutant strains that will contribute to obtaining of cellulosic ethanol. Furthermore, they go to contribute to a better understanding of the regulatory mechanisms and functional properties of cellulases and hemicellulases from T. reesei. (AU)