Functional study of recombinant GH12 xiloglucanases for xyloglucan hydrolysis

• Grant number: 12/01082-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: April 01, 2012
• End date: June 30, 2012
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: André Ricardo de Lima Damasio
• Grantee: Henrique Priori Polo
• Host Institution: Centro Nacional de Pesquisa em Energia e Materiais (CNPEM). Ministério da Ciência, Tecnologia e Inovação (Brasil). Campinas , SP, Brazil

Abstract

Much of the world scenario is currently focused on research related to biofuels, ways of reducing CO2 released into the atmosphere and renewable energy. Among these topics, Brazil stands out in the use of bioethanol as well as use it to supply much of the country's vehicles and reduce dependence on oil as well as exporting. Due to the great importance of this fuel, several studies proposing the production of more ethanol from agro-industrial residues such as bagasse, are very interesting economically. Enzymatic hydrolysis of cellulose needed for the production of second generation ethanol undergoes many difficulties, because its fibers are covered by other types of polysaccharides, which require the use of accessory enzymes, so as to ensure the cellulose exposure. Among these polysaccharides is xyloglucan, which is intimately connected to these fibers, and xiloglucanases are essential to allow the access of cellulases. In this study will be carried out cloning and expression of Aspergillus clavatus GH12 xiloglucanases, using Aspergillus nidulans strain A773 as a system of expression and secretion. To follow the studies will be selected the transformants with the best enzyme secretion level. The secreted target enzymes will be purified and characterized. We also will carry out a detailed study on the enzymes glycosylation effects, and what is the glycosylation influence on the activity against the substrate. Aspergillus is especially promising as a system for recombinant protein expression, because it has all machinery for translation, folding and post-translational modifications, in addition to producing excellent results in the amount of proteins secreted into the medium. Thus functional studies will be undertaken for cloned xiloglucanases GH12 by analyzing the potential of these enzymes on the hydrolysis of xyloglucan. (AU)