Isolation and identification of highly effective potassiumsolubilising bacterial strain from coastal soils

Soil potassium supplementation relies heavily on the use of chemical fertilizer, which has a considerablenegative impact on the environment. Potassium-solubilizing bacteria (KSB) could serve as inoculants.They convert insoluble potassium in the soil into a form that plants can access. This is a promising strat-egy for the improvement of plant absorption of potassium and so reducing the use of chemical fertilizer. In order to overcome poor potassium availability, potassium solubilising microorganisms can be used to ensure agriculture production. Hence, the study was aimed to isolate, identify, and characterise a potent bacterial species from coastal soils that can efficiently solubilise phosphate for plant absorption. From the five soil samples, a total of eight different discrete bacterial colonies were identified and they were named as MGK-01, MGK-02, MGK-03, MGK-04, MGK-05, MGK-06, MGK-07 and MGK-08. The screening of potassium solubilisation demonstrates that the greatest potassium solubilisation ability was found in the MGK-06 strain. Furthermore, the greatest potassium solubilisation under increasing NaCl concentrations were found in the MGK-06. Due to better potassium solubility and plant growth promoting activities, bacterial isolate MGK-06 was selected for molecular identification and bioinoculation studies. The molecular phylogeny revealed that the bacterial isolate MGK-06 is belongs to Azotobacter chrococcumspecies.