Pseudomonas brassicacearum siderophores as mineral weathering agents: potential for plant nutritional benefits and carbon sequestration

Girard Tom, Fochesato Sylvain, Duvivier Adrien, Doelsch Emmanuel, Heulin Thierry, Basile-Doelsch Isabelle, Achouak Wafa. 2023. Pseudomonas brassicacearum siderophores as mineral weathering agents: potential for plant nutritional benefits and carbon sequestration. In : 16th Plant Bacteria Meeting. Abstract Booklet. INRAE. Aussois : INRAE, Résumé, 136. Rencontres plantes-bactéries. 16, Aussois, France, 20 Mars 2023/24 Mars 2023.

Résumé : Multiple mineral weathering bacteria (i.e. bacteria that are able to dissolve or transform minerals) have been identified in soils. Among the molecules responsible of mineral weathering, chelating agents such as low molecular weight organic acids and siderophores are frequently described. Pseudomonas brassicacearum NFM421 is a root-associated bacterium capable of producing two different types of siderophores: pyoverdine (a fluorescent siderophore) and ornicorrugatine. This bacterium is also able to transform glucose into gluconic and cetogluconic acid. We constructed different mutants of this strain in which we deleted the gene coding for pyoverdine, ornicorrugatine or both. Another mutant lacking the pleiotropic regulatory gene gacA was identified as a pyoverdine hyperproducer. The aim of this study is to compare the mineral weathering potential of these strains and to investigate the effect of microbial exopolysaccharides on mineral weathering and carbon stabilization. To date, we demonstrated that the metabolites produced by this strain in iron deficient growth media (mainly pyoverdine and organic acid) are able to dissolve structural iron, aluminum and silicium from a phyllosilicate mineral (biotite). In natural soils, this ability can allow the bacteria and surrounding plants to overcome the lack of bioavailable inorganic nutrients such as iron and could contribute to the stabilization of soil organic carbon by enhancing organo-mineral association.

Auteurs et affiliations

• Girard Tom, CIRAD-PERSYST-UPR Recyclage et risque (FRA)
• Fochesato Sylvain, Université Aix-Marseille (FRA)
• Duvivier Adrien, CEREGE (FRA)
• Doelsch Emmanuel, CIRAD-PERSYST-UPR Recyclage et risque (FRA) ORCID: 0000-0002-7478-4296
• Heulin Thierry, CEA (FRA)
• Basile-Doelsch Isabelle, CEREGE (FRA)
• Achouak Wafa, CEA (FRA)

Source : Cirad-Agritrop (https://agritrop.cirad.fr/606522/)

Métriques

[ Page générée et mise en cache le 2023-09-26 ]