Characterization of wcb cluster of B. seminalis strains TC3.4.2R3 and its role in the biosynthesis of antimicrobial compounds

Abstract

Bacteria of the genus Burkholderia have high nutritional versatility and have been used for various purposes such as agricultural management, biocontrol, biodegradation / bioremediation and plant growth promotion. Several compounds with antimicrobial activity produced by Burkholderia spp. have been investigated, which could replace conventional chemical pesticides. Genes of Burkholderia seminalis strain TC3.4.2R3 associated to the synthesis of antimicrobial compounds were previously identified by analyzing a mutant library (FAPESP proc. no. 2008/52407-9; no. 2008/52406-2; no. 08/56505-5), among these genes, we identified a gene that encode a glucosyltransferase which is described in stage of modification of secondary metabolites with antimicrobial activity. Therefore, this project aims to evaluate the role of cluster wcb that has this gene in the synthesis of secondary metabolites of B. seminalis TC3.4.2R3 strain. For this, the region of the genome of B. seminalis TC3.4.2R3 strain, where this gene is located will be further evaluated and genes of interest will be cloned and used for complementation studies and site directed mutation. These mutants also will be evaluated for the metabolic profile compared to the wild type strain by metabolomics approach. Pairing test conducted for mutants M3, M4 and M7 and the wild strain of Burkholderia against phytopathogenic fungi revealed all mutants lost their ability to inhibit pathogens compared to the wild type. Contigs obtained from sequencing of Burkholderia were analyzed by bioinformatics software and tools. Genes upstream and downstream and potential promoter regions were annotated allowing to observe that 2 ORFs (hypothetical protein and dTDP-4 dehydrorhamnose 3,5-epimerase) in this cluster are unique in this species in Burkholderia genus. (AU)