Affiliation:
1. Département de Biotechnologie, Centre de Recherches Agronomiques de Gembloux, Ministère des Classes Moyennes et de l'Agriculture, B-5030 Gembloux, Belgium
Abstract
ABSTRACT
The production of peptide siderophores and the variation in siderophore production among strains of
Pseudomonas syringae
and
Pseudomonas viridiflava
were investigated. An antibiose test was used to select a free amino acid-containing agar medium favorable for production of fluorescent siderophores by two
P. syringae
strains. A culture technique in which both liquid and solid asparagine-containing culture media were used proved to be reproducible and highly effective for inducing production of siderophores in a liquid medium by the fluorescent
Pseudomonas
strains investigated. Using asparagine as a carbon source appeared to favor siderophore production, and relatively high levels of siderophores were produced when certain amino acids were used as the sole carbon and energy sources. Purified chelated siderophores of strains of
P. syringae
pv. syringae,
P. syringae
pv. aptata,
P. syringae
pv. morsprunorum,
P. syringae
pv. tomato, and
P. viridiflava
had the same amino acid composition and spectral characteristics and were indiscriminately used by these strains. In addition, nonfluorescent strains of
P. syringae
pv. aptata and
P. syringae
pv. morsprunorum were able to use the siderophores in biological tests. Our results confirmed the proximity of
P. syringae
and
P. viridiflava
; siderotyping between pathovars of
P. syringae
was not possible. We found that the spectral characteristics of the chelated peptide siderophores were different from the spectral characteristics of typical pyoverdins. Our results are discussed in relation to the ecology of the organisms and the conditions encountered on plant surfaces.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology