Microbial Phosphorus Mobilization Strategies Across a Natural Nutrient Limitation Gradient and Evidence for Linkage With Iron Solubilization Traits

• DOI: 10.3389/fmicb.2021.572212
• Publication Date: 2021-06-23T06:31:27Z
• Authors: Shi Wang; Robert Walker; Marcus Schicklberger; Peter S. Nico; Patricia M. Fox; Ulas Karaoz; Romy Chakraborty; Eoin L. Brodie
• Keywords: Phytase; Phosphorite

Microorganisms have evolved several mechanisms to mobilize and mineralize occluded insoluble phosphorus (P), thereby promoting plant growth in terrestrial ecosystems. However, the linkages between microbial P-solubilization traits preponderance of P natural ecosystems are not well known. We tested solubilization hundreds culturable bacteria representative rhizosphere from a gradient where concentration bioavailability decline as soil becomes progressively more weathered. Aluminum, iron phosphate organic (phytate) were expected dominate weathered soils. A defined cultivation medium with these chemical forms was used for isolation. combination chemical, spectroscopic analyses 16S rRNA gene sequencing understand situ ability predominant P. Locations harbored greatest abundance P-mobilizing microorganisms, especially Burkholderiaceae ( Caballeronia Paraburkholderia spp.). Nearly all utilized aluminum phosphate, however fewer could subsist on (FePO 4 ) or phytate. isolated phytic acid also most effective at solubilizing FePO , suggesting that phytate may be linked solubilize Fe. Significantly, we observed Fe co-located patches soil. Siderophore addition lab experiments reinstated phytase mediated Fe-phytate complexes. Taken together, results indicate metal-organic-P complex formation limit enzymatic Additionally, siderophore production mostly restricted specific clades within . propose complexation (e.g., phytate) represents major constraint turnover availability acidic soils, only limited subset appear possess required access this persistent pool