Phosphate solubilizing bacteria

It is generally accepted that the mechanism of mineral phosphate solubilization by PSB strains is associated with the release of low molecular weight organic acids, through which their hydroxyl and carboxyl groups chelate the cations [an ion that have positive charge on it.]

However, a large portion of soluble inorganic phosphate which is applied to the soil as chemical fertilizer is immobilized rapidly and becomes unavailable to plants.

Simple inoculation of seeds with PSB gives crop yield responses equivalent to 30 kg P2O5 /ha or 50 percent of the need for phosphatic fertilizers.

Recently, researchers at Colorado State University demonstrated that a consortium of four bacteria, synergistically solubilize phosphorus at a much faster rate than any single strain alone.

Considering the geochemical interaction between these two elements, the authors suggest that some bacteria can dissolve iron-containing minerals in order to access the adsorbed phosphate.