Persistence and cell culturability of biocontrol strain Pseudomonas fluorescens CHA0 under plough pan conditions in soil and influence of the anaerobic regulator gene anr.

Détails

ID Serval
serval:BIB_8464624A06E2
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Persistence and cell culturability of biocontrol strain Pseudomonas fluorescens CHA0 under plough pan conditions in soil and influence of the anaerobic regulator gene anr.
Périodique
Environmental Microbiology
Auteur(s)
Mascher F., Schnider-Keel U., Haas D., Défago G., Moënne-Loccoz Y.
ISSN
1462-2912[print], 1462-2912[linking]
Statut éditorial
Publié
Date de publication
2003
Volume
5
Numéro
2
Pages
103-115
Langue
anglais
Résumé
Certain fluorescent pseudomonads can protect plants from soil-borne pathogens, and it is important to understand how these biocontrol agents survive in soil. The persistence of the biocontrol strain Pseudomonas fluorescens CHA0-Rif under plough pan conditions was assessed in non-sterile soil microcosms by counting total cells (immunofluorescence microscopy), intact cells (BacLight membrane permeability test), viable cells (Kogure's substrate-responsiveness test) and culturable cells (colony counts on selective plates) of the inoculant. Viable but non-culturable cells of CHA0-Rif (106 cells g-1 soil) were found in flooded microcosms amended with fermentable organic matter, in which the soil redox potential was low (plough pan conditions), in agreement with previous observations of plough pan samples from a field inoculated with CHA0-Rif. However, viable but non-culturable cells were not found in unamended flooded, amended unflooded or unamended unflooded (i.e. control) microcosms, suggesting that such cells resulted from exposure of CHA0-Rif to a combination of low redox potential and oxygen limitation in soil. CHA0-Rif is strictly aerobic. Its anaerobic regulator ANR is activated by low oxygen concentrations and it controls production of the biocontrol metabolite hydrogen cyanide under microaerophilic conditions. Under plough pan conditions, an anr-deficient mutant of CHA0-Rif and its complemented derivative displayed the same persistence pattern as CHA0-Rif, indicating that anr was not implicated in the formation of viable but non-culturable cells of this strain at the plough pan.
Mots-clé
Agriculture/methods, Anaerobiosis, Bacterial Proteins/genetics, Bacterial Proteins/metabolism, Culture Media, DNA-Binding Proteins, Gene Expression Regulation, Bacterial, Mutation, Oxidation-Reduction, Pest Control, Biological, Pseudomonas fluorescens/growth & development, Soil Microbiology, Trans-Activators, Transcription Factors/genetics, Transcription Factors/metabolism
Pubmed
Web of science
Création de la notice
25/01/2008 18:01
Dernière modification de la notice
03/03/2018 18:54
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