Collection and analysis of a random library of X. campestris pv. campestris generated by Transposoma searching for mutants with high viscosity xanthan gum.

• Grant number: 10/01662-9
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: November 01, 2010
• End date: October 31, 2011
• Field of knowledge: Biological Sciences - Microbiology - Applied Microbiology
• Principal Investigator: Pedro de Oliva Neto
• Grantee: Samuel Matos da Costa
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil

Abstract

Xanthan gum is a soluble heteropolysaccharide produced industrially by fermentation of sucrose by the bacterium Xanthomonas campestris. Its excellent rheological properties, such as high viscosity (even at low concentrations), contribute to the growing number of applications in food industries and tertiary recovery of oil. Although the genome sequence of this bacterium has already been revealed, there are numerous attempts to generate different strains which can produce a gum with high viscosity. The selection of microorganisms that produce polysaccharide with functional properties, economically attractive, is also a constant challenge. In order to find transformants capable of producing high viscosity gum, this project aims to generate a random library of about 2000 of a mutant strain of Xanthomonas campestris pv. campestris [FCLA B26 widely characterized as regard to their medium and means of gum production] from its mutagenesis using the Transposoma Tn5. This will be done for preparing competent cells, and subsequently performing the electroporation of Transposoma. The selection of transformants will be held, according to the literature, considering the characteristics of the colony as well as the size of halo when grown in agar-starch. The values of the viscosity of fermentation broth and 1% xanthan gum from these mutants will be analyzed by a viscometer. Values yield of gum (Yx / s) and amount of biomass (Yp / s) will be calculated and compared (for statistical analysis) between the mutants and their parent strain (FCLA B26).