Characterization of the Methyltransferase gene present in the O-antigen gene cluster of the endophytic Burkholderia seminalis TC3.4.2R3, and the role of this gene in the synthesis of antimicrobial compounds.
Burkholderia is the object of studies that aim at various biotechnological applications as biocontrol agents, plant growth promoters and bioremediation as producers of major molecules of interest. The Burkholderia seminalis TC3.4.2R3 strain is an endophytic organism isolated from sugarcane roots and shows the ability to inhibit plant pathogenic fungus and bacteria. Gene clusters of B. seminalis strain TC3.4.2R3 associated to the synthesis of antimicrobial compounds have been identified by analyzing a Tn5 transposon mutant library in previous studies, among them, a methyltransferase (Bsem_02858). This gene is localized close to the antigen-O cluster, which is responsible for the synthesis of LPS (lipopolysaccharide) and also microbial interactions, it was observed that the mutation in this gene alters the pattern of interaction between B. seminalis TC3.4.2R3 and phytopathogenic microorganisms (such as Fusarium oxysporum, Ceratocystis fimbriata, Ceratocystis paradoxa and Colletotrichum sp.), therefore we believe that there is a possible involvement of methyltransferase in the production of antibiotics compounds. However, knowledge about the interaction and control mechanisms of the metabolites with antimicrobial properties in Burkholderia spp. is still incipient. Our main objective is to reach a better understanding of the possible mechanisms involved in the inhibition of plant pathogens by B. seminalis TC3.4.2R3 and the role of the methyltransferase gene in this process. The research internship abroad aims to obtain and analyze mutants with deleted methyltransferase, glycosyltransferase genes and also other genes close to the O-antigen cluster as those responsible for the polymerization of the O-antigen structure and then the correlation between these genes and the B. seminalis antibiotic ability. Furthermore, B. seminalis TC3.4.2R3 obtained mutants, wild-type strains and also Burkholderia cenocepacia will be assessed for virulence activity in macrophage and wax moth larvae (Galleria mellonella) infection models, which will allow the comprehension of the mechanisms related to the interaction between B. seminalis TC3.4.2R3 and organisms in the environment. The research will be conducted in the Wellcome-Wolfson Institute for Experimental Medicine, Queen's University of Belfast under Prof. Dr. Miguel A. Valvano's supervision, who has extensive experience in the study of the lipopolysaccharide at the molecular level by several approaches. The results will contribute to the enrichment of the candidate thesis, which follows with biochemistry and metabolomics analysis of LPS extracts with antimicrobial activity obtained from B. seminalis TC3.4.2R3.
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