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Isolation and identification of potassium‐releasing bacteria in soil and assessment of their ability to release potassium for plants
- Sarikhani, M. R., Oustan, S., Ebrahimi, M., Aliasgharzad, N.
- European journal of soil science 2018 v.69 no.6 pp. 1078-1086
- Pseudomonas, bacteria, biomass, biotite, liquids, muscovite, plant tissues, pot culture, potassium, soil, soil sampling, solubilization, tomatoes
- SUMMARY: The application of potassium (K)‐releasing microorganisms is a promising approach for increasing K availability in soil. The objectives of this study were to isolate and characterize the K‐releasing bacteria (KRB) and to evaluate their contribution to the solubilization of K from muscovite and biotite, and to the assimilation of released K by tomato in a pot culture experiment. Soil samples were screened in both solid and liquid Aleksandrov media to isolate bacteria with the potential to release K from biotite and muscovite. Our results from in‐vitro experiments revealed that more K was released in treatments with KRB than in the uninoculated media (control). Under the best conditions an increase of 188 and 127% was obtained for biotite and muscovite, respectively; among the isolates with the largest releasing ability it was 49 mg l⁻¹. The most efficient bacteria were identified as the Pseudomonas genus. Results of the pot culture experiment showed that the concentration and content of K in plant tissue were considerably more than those in any of the controls with no living organisms present. Results revealed that significantly more biomass was accumulated and K acquired in most pots treated with bacterial strains than in the control, especially for Pseudomonas sp. strain S10‐3. This treatment increased K concentation and content by more than 50 and 70%, respectively, in tomato aerial tissue. Further research is necessary to examine the effects of these bacterial strains on the mobilization of K‐bearing minerals under field conditions. HIGHLIGHTS: The aim was to determine if bacterial isolates can accelerate K release from micas for plants. We investigated the potential of some isolated bacteria to solubilize K from muscovite and biotite. Identification of efficient isolates showed that KRB belonged to the Pseudomonas genus. Pseudomonas sp. strain S10‐3 increased K concentration in tomato aerial tissue by more than 50%.