Vibrioferrin production by the food spoilage bacterium Pseudomonas fragi. Issue 6 (20th December 2017)

• Record Type: Journal Article
• Authors: Stanborough, Tamsyn; Fegan, Narelle; Powell, Shane M; Tamplin, Mark; Chandry, P Scott
• Is Part Of: FEMS microbiology letters. Volume 365:Issue 6(2018:Mar.)
• Publication Date: 2017-12-20
• Subjects: Pseudomonas fragi -- siderophore -- vibrioferrin -- food spoilage -- iron acquisition -- iron chelators; Microbiology -- Periodicals; 579
• DOI: 10.1093/femsle/fnx279
• Languages: English
• ISSNs: 0378-1097

Abstract

Abstract: Pseudomonas fragi is a meat and milk spoilage bacterium with high iron requirements; however, mechanisms of iron acquisition remain largely unknown. The aim of this work was to investigate siderophore production as an iron acquisition system for P. fragi . A vibrioferrin siderophore gene cluster was identified in 13 P. fragi, and experiments were conducted with a representative strain of this group (F1801). Chromeazurol S assays showed that P. fragi F1801 produced siderophores under iron starvation at optimum growth and refrigeration temperature. Conversely, supplementation of low iron media with 50 μM FeCl3 repressed transcription of the vibrioferrin genes and siderophore production. Disruption of the siderophore receptor ( pvuA ) caused polar effects on downstream vibrioferrin genes, resulting in impaired siderophore production of the Δ pvuA mutant. Growth of this mutant was compared to growth of a control strain (Δ lip ) with wild-type vibrioferrin genes in low iron media supplemented with iron chelators 2, 2΄-bipyridyl or apo-transferrin. While 25 μM 2, 2΄-bipyridyl caused impaired growth of Δ pvuA, growth of the mutant was completely inhibited by 2.5 μM apo-transferrin, but could be restored by FeCl3 addition. In summary, this work identifies a vibrioferrin-mediated iron acquisition system of P. fragi, which is required for growth of this bacterium under iron starvation. Abstract : Pseudomonas fragi produces a vibrioferrin siderophore that plays a role in iron acquisition under low iron conditions.