A gacS deficiency affects bacteriocin production in Pseudomonas putida MGR37

CORDERO, P.; PRINCIPE, A.; GODINO, A.; MEDEOT, D.; JOFRÉ, E.; MORI, G.; FISCHER, S.

Congreso; XLVIII Reunión anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2012

The plant growth-promoting rhizobacterium, MGR37 secretes bacteriocins which kill a wide range of bacteria related to the genus. The aim of this work was the identification of genetic determinants involved in the production of such compounds. In this sense, a collection of MGR37 mutants was generated by Tn5-B21 mutagenesis and screened by the inability to produce antimicrobial compounds. An isogenic Tn5-B21 mutant that had lost the capacity to inhibit the growth of CTR212 was selected and further characterized. This mutant, designated 646 carries a single transposon insertion into an ORF homologous to a gene from several members of genus. This gene encodes for a histidin kinase sensor of the two-component system GacA/GacS. In addition, the mutant 646 showed a cell phenotype of non-attached aggregates and a diminished in the biofilm formation. These results suggest that a mutation in the gene affects a variety of phenotypes which are important for the bacterial competitiveness within the environmental. Complementation assays are being carried out to demonstrate the implication of the two-component system GacS/GacA in the production of antibacterial compounds such as bacteriocins.