Isolation and Characterization of Phosphorus Solubilizing Bacteria With Multiple Phosphorus Sources Utilizing Capability and Their Potential for Lead Immobilization in Soil

Abstract

Phosphorus solubilizing bacteria (PSB) can promote the level of plant-absorbable phosphorus (P) in agro-ecosystems. However, little attention has been paid to PSB harboring abilities in utilizing multiple phosphorus sources and their potentials for heavy metal immobilization. In this study, we applied the strategy of stepwise acclimation by using Ca 3 (PO 4) 2 , phytate, FePO 4 , and AlPO 4 as sole P source. We gained 18 PSB possessing abilities of multiple P sources utilization, and these bacteria belonged to eight genera (Acinetobacter, Pseudomonas, Massilia, Bacillus, Arthrobacter, Stenotrophomonas, Ochrobactrum, and Cupriavidus), and clustered to two apparent parts: Gram-positive bacteria and Gram-negative bacteria. The isolate of Acinetobacter pittii gp-1 presented good performance for utilizing Ca 3 (PO 4) 2 , FePO 4 , AlPO 4 , and phytate, with corresponding P solubilizing levels were 250.77, 46.10, 81.99, and 7.91 mg/L PO 4 3−-P, respectively. The PSB A. pittii gp-1 exhibited good performance for solubilizing tricalcium phosphate in soil incubation experiments, with the highest values of water soluble P and available P were 0.80 and 1.64 mg/L, respectively. Additionally, the addition of A. pittii gp-1 could promote the immobilization of lead (Pb), and the highest Pb immobilization efficiency reached 23%. Simultaneously, we found the increases in abundances of both alkaline phosphatase gene (phoD) and β-propeller phytase gene (bpp) in strain gp-1 added soils. Besides, we observed the expression up-regulation of both pyrroloquinoline quinone gene (pqq) and polyphosphate kinases gene (ppk), with the highest relative expression levels of 18.18 and 5.23, respectively. We also found the polyphosphate particles using granule staining. To our knowledge, our findings first suggest that the solubilizing of tricalcium phosphate by phosphorus solubilizing bacterium belonging to Acinetobacter is coupled with the synthesis of polyphosphate. Taken together, A. pittii gp-1 could be a good candidate in improving soil fertility and quality.

Genomic Analysis of the Endophytic Stenotrophomonas Strain 169 Reveals Features Related to Plant-Growth Promotion and Stress Tolerance

“…Genes encoding acid and alkaline phosphatases and a phytase were found in the genome of strain 169 ( Supplementary Table 1 ). Additionally, genes mediating polyphosphate formation ( ppk ) ( Wan et al, 2020 ) and phosphonoacetate degradation ( phnA ) ( Shariati et al, 2017 ) were present in the genome. Phosphate starvation-inducible glucose dehydrogenase (EC 1.1.5.2) encoded by the gcd gene may also be involved in the solubilization of mineral phosphates ( Sharma et al, 2005 ).…”

Seed bio-priming with tri-species consortia of phosphate solubilizing rhizobacteria (PSR) and its effect on plant growth promotion

“…Burkholderia sp., Enterobacter sp., Pseudomonas sp., and Staphylococcus sp. are the most prominent phytate solublizers [46,47,48]. Kumar et al [39] found in a study that Bacillus sp.…”

“…All the three potential strains efficiently solubilized CP and SP and produced halo zone around spot inoculation indicating the release of free P. Plant growth promoting rhizobacteria such as Bacillus sp., Burkholderia sp., Enterobacter sp., Pseudomonas sp., and Staphylococcus sp. are the most prominent phytate solublizers [ 46 , 47 , 48 ]. Kumar et al.…”

Phosphate-Solubilizing Fungi and Alkaline Phosphatase Trigger the P Solubilization During the Co-composting of Sorghum Straw Residues With Burkina Faso Phosphate Rock

“…However, since pqqA, pqqB, pqqC, pqqD, and pqqE genes are conserved and arranged in that order in the pqq operon (pqqABCDE) (Shen et al, 2012), we selected the pqqB and pqqE genes to study the mPSB. Given the substantial wide distribution of PSB in natural ecosystems including soils, freshwater, seawater, and sediments (Zhang et al, 2015;Liang et al, 2020;Wan et al, 2020), we cannot completely rule out a possible contribution of phosphate solubilizing bacteria in the increase of P fractions in our compost treatments. The moderate but positive correlation of 16S bacteria with the labile-P supports the possibility of bacteria to intervene in the P solubilization in the composts.…”