Production and crystallization of a recombinant xylanase from Leucoagaricus gongylophorus, symbiotic fungus of leaf cutting ants

• Grant number: 11/15060-3
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): March 01, 2012
• Effective date (End): July 31, 2013
• Field of knowledge: Biological Sciences - Biochemistry - Chemistry of Macromolecules
• Principal Investigator: Dulce Helena Ferreira de Souza
• Grantee: Ariele Cristina Moreira
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Xylanases are enzymes that randomly cleave the backbone of xylan, the most abundant polysaccharide non-cellulosic cell wall of plants. This enzyme has a large biotechnology application, especially in bio pulp bleaching in paper production, the improvement of animal nutrition and production of the sweetener xylitol. Recent studies have shown that by incorporating the xylanases in the fermentation process for ethanol production from agro-residues of second-generation ethanol, you get a 28% increase in ethanol production. This is a very interesting aspect to be addressed due to the high level of cellulosic waste generated in the country and search for sources of renewable fuels and less polluting than fossil fuels. The proposed project will involve the amplification of the gene that encodes the synthesis of the fungal xylanase Leucoagaricus gongylophorus, symbiotic fungus of leaf cutting ants by PCR using as template the cDNA obtained from RNA extracted from fungal culture. After gene amplification, it will be cloned into plasmid pGEM for propagation and after, the gene will be cloned in the plasmid pPICZ±-C, an expression vector in yeast Pichia pastoris. The enzyme will be expressed, purified and characterized from the point of view of kinetics. The protein will also be crystallized for future structural studies of xylanase by X-ray diffraction. The information structure and function of the enzyme are important for further studies to improve their activities / stability through site-directed mutations.