The novel and efficient method for isolating potassium solubilizing bacteria from rhizosphere soil

AbstractPotassium (K) is the third major essential macronutrient for plant growth and more than 90% of potassiumin the soil exists in the form of insoluble rocks and silicate minerals. 150 potassium solubilizingbacterial (KSB) strains were isolated from rhizosphere soil using Aleksandrov medium containing insoluble mica powder. Ten efficient KSB strains were selected and quantification studies showed that higher K solubilization(50.6 mg L−1) was observed in the strain HMP27 followed by strain WHP47 (46.4 mg L−1) in liquid medium. Potassium solubilizationby the bacterial strains is determined by measuring zone of clearance around the bacterial colony. This procedure requires 10–15 days incubation. Therefore, a simple, rapid, and user-friendly method has been developed for screening of potassium solubilizingbacteria using the bromothymol bluedye in modified Aleksandrov medium. Microorganisms possessing potassium solubilizationproperty developed a clear zone around bacterial colony and changed the col...