Evaluation of the biotechnological potential of mutant strains of Rhizobium tropici

• Grant number: 10/13242-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2011
• End date: May 31, 2012
• Field of knowledge: Biological Sciences - Biochemistry - Biochemistry of Microorganisms
• Principal Investigator: Jackson Antônio Marcondes de Souza
• Grantee: Hemelin Ludmila dos Santos
• Host Institution: Faculdade de Ciências Agrárias e Veterinárias (FCAV). Universidade Estadual Paulista (UNESP). Campus de Jaboticabal. Jaboticabal , SP, Brazil

Abstract

Recently, Brazil has occupied the world first place in the production and consumption of beans This crop is used as a staple food and a major source of protein in the diet of the population. Due to the economic and social importance of beans in Brazil, studies aiming to optimize the process of nodulation and biological nitrogen fixation are necessary and consist in an important practice. Among the species of Rhizobium nitrogen-fixing, most individuals isolated from Brazilian soils belong to the species R. tropici. The bean develops roots in symbiotic association with bacteria, when they are present in the soil, either naturally or through inoculation. They recognize and infect the roots of the host plant, triggering nodule formation where N2 fixation takes place. The bacterial genes involved in the formation of the nodules are divided into two classes: 1) genes that specify the biochemical composition of the bacterial cell surface, such as those that determine the synthesis of exopolysaccharides and lipopolysaccharides, exo and lps genes, respectively, and 2) genes related to the production of capsular polysaccharides, antigens K and betha-1,2-glucans, besides genes ndv (nodule development). Rhizobia strains are efficient producers of exopolysaccharides and such exudates present complex structure involved in processes of infection and biological nitrogen fixation (BNF). In this project we intend to perform the characterization of the process of symbiotic nitrogen fixation of genetically modified organisms in relation to their wild-type SEMIA 4080 through accessing gene expression by quantitative real-time PCR of some specific genes related to central intermediary metabolism and energy metabolism. This correlation was important since the anabolic and catabolic pathways of Carbon:Nitrogen ratio are guided by them, which are essential in the production of molecules important to BNF.

Academic Publications

(References retrieved automatically from State of São Paulo Research Institutions)

SANTOS, Hemelin Ludmila dos. Avaliação do potencial biotecnológico de linhagens mutantes de Rhizobium tropici. 2012. Master's Dissertation - Universidade Estadual Paulista (Unesp). Faculdade de Ciências Agrárias e Veterinárias. Jaboticabal Jaboticabal.