Construction and optimization of a fungal secretion system suitable for high-yield biomass hydrolytic and oxidation enzyme production for structural and functional studies

• Grant number: 14/15887-3
• Support type: Scholarships abroad - Research Internship - Post-doctor
• Effective date (Start): October 06, 2014
• Effective date (End): May 05, 2015
• Field of knowledge: Biological Sciences - Genetics - Molecular Genetics and Genetics of Microorganisms
• Principal researcher: Igor Polikarpov
• Grantee: Marco Antonio Seiki Kadowaki
• Supervisor abroad: Rolf Alexander Prade
• Home Institution: Instituto de Física de São Carlos (IFSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Research place: Oklahoma State University, United States
• Associated to the scholarship: 11/20505-4 - Two important classes of glycosyl hydrolases: functional studies and structural analysis, BP.PD

Abstract

Biomass is a universally abundant, renewable resource useful for the production of biofuels, pharmaceuticals and starting biochemicals that can be converted into plastics and other commercial composites if polymerized sugars may perhaps be extracted. Enzymatic degradation of biomass polymers into fermentable sugars is a recalcitrant process for which a complete efficient breakdown mechanism remains to be discovered. So far current commercial enzymes that breakdown biomass polymers are of the hydrolytic type - they hydrolyse glycosydic bonds that tether sugar units together through the classic acid/base catalysis mechanism. While a hydrolysis mechanism is efficient and sufficient in the breakdown of hemicellulose and pectins, they are inadequate in breaking down crystalline cellulose and lignin. Not all microorganisms breakdown cellulose and other biomass polymers through a hydrolytic mechanism. Fungi such as Myceliophthora thermophila that secrete an array of oxidoreductases and Aspergillus niveus that show to express high levels of cellulases are potential hosts to heterologous protein secretion. M. thermophila can be used to express target oxidases and maybe enhance the expression of thermophilic enzymes. On the other hand A. niveus can offer an alternative option to express the traditional hydrolytic enzymes. The overall goal of this research project is to generate a fungal host able to successfully express and secrete hydrolytic as well as oxidative enzymes like AA9 monooxygenases (formerly known as GH61 endoglucanases) cloned in the present postdoctoral project, cellobiose dehydrogenase, glyoxal- and glucose oxidases. We plan to explore M thermophila and Aspergillus niveus as possible candidates for this work. (AU)