Development of recombinant strains of Xanthomonas campestris for xanthan gum production

• Grant number: 20/00432-1
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2020
• End date: December 31, 2020
• Field of knowledge: Engineering - Chemical Engineering
• Principal Investigator: Adilson José da Silva
• Grantee: Bruno Batista
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil

Abstract

Xanthan gum is a polysaccharide produced by the Xanthomonas genus that has been used for industrial applications in different sectors, like food, cosmetics, and oil extraction, among others. Because there is no national production of this compound in Brazil, we depend on the importation of large amounts of this biopolymer. A key aspect of this process is the development of optimized strains, which has not been properly explored so far. In this context, we started a project in 2017 to develop better strains using tools from the fields of metabolic engineering, systems biology, and synthetic biology. The first results came from a deterministic mathematical model written in Python to describe the synthesis of xanthan gum monomers. After model validation using experimental data from the literature, two reactions were found to be the possible bottlenecks for the xanthan gum biosynthesis. Additional model predictions also pointed for a significant improvement in xanthan gum production after super-expression of the target enzymes. Based on these results, this project aims to validate the in silico predictions by cloning and overexpressing the enzymes described as important bottlenecks in this metabolic pathway.