Thioquinolobactin, a Pseudomonas siderophore with antifungal and anti-Pythium activity.
Under conditions of iron limitation Pseudomonas fluorescens ATCC 17400 produces two siderophores, pyoverdine, and a second siderophore quinolobactin, which itself results from the hydrolysis of the unstable molecule 8-hydroxy-4-methoxy-2-quinoline thiocarboxylic acid (thioquinolobactin). Pseudomonas fluorescens ATCC 17400 also displays a strong in vitro antagonism against the Oomycete Pythium, which is repressed by iron, suggesting the involvement of a siderophore(s). While a pyoverdine-negative mutant retains most of its antagonism, a thioquinolobactin-negative mutant only slowed-down Pythium growth, and a double pyoverdine-, thioquinolobactin-negative mutant, which does not produce any siderophore, totally lost its antagonism against Pythium. The siderophore thioquinolobactin could be purified and identified from spent medium and showed anti-Pythium activity, but it was quickly hydrolysed to quinolobactin, which we showed has no antimicrobial activity. Analysis of antagonism-affected transposon mutants revealed that genes involved in haem biosynthesis and sulfur assimilation are important for the production of thioquinolobactin and the expression of antagonism.
Matthijs
Sandra
S
Laboratory of Microbial Interactions, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute for Biotechnology, Vrije Universiteit Brussel, Building E, Pleinlaan 2, 1050 Brussels, Belgium.
Tehrani
Kourosch Abbaspour
KA
Laus
George
G
Jackson
Robert W
RW
Cooper
Richard M
RM
Cornelis
Pierre
P
D000935:Antifungal Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D004251:DNA Transposable Elements; D006418:Heme / Q000096:biosynthesis; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009154:Mutation; D009842:Oligopeptides / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D011551:Pseudomonas fluorescens / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011775:Pythium / Q000187:drug effects* / Q000254:growth & development; D011804:Quinolines / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D017262:Siderophores / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D013455:Sulfur / Q000378:metabolism
D000935:Antifungal Agents; D004251:DNA Transposable Elements; D009842:Oligopeptides; D011804:Quinolines; D017262:Siderophores; C404845:quinolobactin; C518370:thioquinolobactin; D006418:Heme; D013455:Sulfur; C042453:pyoverdin