1. zanjan university of medical science 2. zanjan university of medical science 3. zanjan university of medical science
Abstract
Introduction
Antibiotic resistance is an important concern in the world and also in iran. identifying new antimicrobial strategies to deal with this problem is one of the constructive solutions. white line reaction (wlr), that is, a white line formation through interactions of lipopeptides secreted by pseudomonads, might be a remarkable defensive strategy against pathogenic microorganisms. understanding such defensive strategy might broaden our insights on new strategy of controlling pathogenic bacteria. in this study we investigated the mechanism of the wlr in pseudomonas gingeri.
Methods
We identified and cloned the plasposon insertion site in four mutants of pseudomonas gingeri created by random mutagenesis. through in silico analysis the knocked out genes were functionally analyzed and compared to known ones.
Results
In silico analysis showed that the knocked out genes in the mutants include disease resistance protein/ tetratricopeptide repeat-containing protein, alge, glutamyl-q-trna synthetase and a hypothetical gene. according to our data none of them has direct role in lipopeptide production. however they influence some procedures like as protein-protein interaction, secretion of lipopeptide and amino acid transfer.
Conclusion
Lipopeptides are usually biosynthesized by nrpss (non-ribosomal peptidosynthetase) in pseudomonas species having wlr. unexpectedly we observed no nrps mutation in neither our mutants nor other mutants of the library. therefore it seems that nrpss mutation probably results in bacterial death in pseudomonas gingeri. consequently we can suggest that lipopeptide producing genes are presumably essential genes in pseudomonas gingeri.
