Characterization of the Mineral Phosphate-Solubilizing Activity of Pantoea aglomerans MMB051 Isolated from an Iron-Rich Soil in Southeastern Venezuela (Bolívar State)

Abstract

The mineral phosphate-solubilizing (MPS) activity of a Pantoea agglomerans strain, namely MMB051, isolated from an iron-rich, acidic soil near Ciudad Piar (Bolívar State, Venezuela), was characterized on a chemically defined medium (NBRIP). Various insoluble inorganic phosphates, including tri-calcium phosphate [Ca 3 (PO 4 ) 2 ], iron phosphate (FePO 4 ), aluminum phosphate (AlPO 4 ), and Rock Phosphate (RP) were tested as sole sources of P for bacterial growth. Solubilization of Ca 3 (PO 4 ) 2 was very efficient and depended on acidification of the external milieu when MMB051 cells were grown in the presence of glucose. This was also the case when RP was used as the sole P source. On the other hand, the solubilization efficiency toward more insoluble mineral phosphates (FePO 4 and AlPO 4 ) was shown to be very low. Even though gluconic acid (GA) was detected on culture supernatants of strain MMB051, a consequence of the direct oxidation pathway of glucose, inorganic-P solubilization seemed also to be related to other processes dependent on active cell growth. Among these, proton release by ammonium (NH 4 ? ) fixation appeared to be of paramount importance to explain inorganic-P solubilization mediated by strain MMB051. On the contrary, the presence of nitrate (NO 3 -) salts as the sole N source affected negatively the ability of MMB051 cells to solubilize inorganic P.

Isolation and identification of a phosphate-solubilizing bacterium Pantoea stewartii subsp. stewartii g6, and effects of temperature, salinity, and pH on its growth under indoor culture conditions

“…When solubilization occurred, the reduction in pH of the medium was noticed. These results indicated that acidification seemed to be the main mechanism of inorganic phosphate solubilization, which are in agreement with previous reports (Sulbarán et al 2009;Pérez et al 2007). …”

Biofertilising, plant-stimulating and biocontrol potentials of maize plant growth promoting rhizobacteria isolated in central and northern Benin

“…As for S. marcescens strains was moderately effective with an SI of 366.93%. The good solubilizing efficiency of % growth inhibition = d1 − d2 d1 × 100 Pseudomonas obtained in our study was also reported in the works done by Sulbaran et al (2008) and Chibani (2017). Messele and Pant (2012) observed improved biological yield and P uptake in chickpea (Cicer arietinum L.) by phosphate-solubilizing Pseudomonas.…”

Sugarcane Growth Promotion by the Endophytic Bacterium Pantoea agglomerans 33.1

“…for systemic resistance induction (37,44,56) and protection against pests and plant-pathogenic microorganisms (4,9,28,35,58). Additionally, these bacteria may induce plant growth by increasing the nitrogen supply in nonsymbiotic associations (2,7,69,79,80), solubilizing phosphorus (45,46,72), and stimulating phytohormone production (78,85).…”