Disruption of transporter genes in the enantio-pyochelin biosynthesis gene cluster of Pseudomonas protegens Pf-5 has pleitropic phenotypic effects
Pseudomonas protegens Pf-5 is a biocontrol bacterium that produces the siderophore enantio-pyochelin under conditions of iron starvation which has the function of scavenging iron. In addition, biosynthetic intermediates of salicylic acid and dihydroaeruginoic acid are usually secreted as well. In this study, we tried to elucidate the roles of three putative transporters that are encoded by the genes PFL_3495, PFL_3503 and PFL_3504 via gene truncation experiments. Out of expectation, truncation of these genes resulted in increased secretion of these products in the culture supernatants. Transcriptional profiling revealed altered expression of the biosynthetic gene cluster by PFL_3504 mutant but not by the PFL_3495 and PFL_3503 mutants. Phenotype microarray revealed that these mutants have different stress and chemical resistance profile when compared to the wild-type.