ISOLATION AND SCREENING OF PHOSPHATE AND POTASH SOLUBILIZING BACTERIA FROM RHIZOSPHERE SOIL OF MAIZE AND COTTON

The availability of soil fertility and growth of plants mainly depends on the interaction of microorganisms with soil nutrients. However, Phosphorus and potassium are indeed essential nutrients for plant growth, but they are often present in the soil as insoluble forms. A microorganism plays a critical role in nutrient mobilization, hence reducing the reliance on chemical fertilizers. The objective of this research is to isolate and screen Phosphate-Solubilizing Bacteria (PSB) and Potash-Solubilizing Bacteria (KSB) from the rhizospheric soil of maize (Zea mays) and cotton (Gossypium herbaceum). 38 different colonies of distinct bacteria were isolated and then screened using Pikovskaya’s agar and Aleksandrow’s agar. Through morphological identification and biochemical characterization, there were 14 isolates with the same morphology as well as 24 unique isolates. Out of them, 12 strains could solubilize phosphate, 10 could dissolve potassium, and 8 could perform both activities simultaneously. The two highest isolates for phosphate-solubilizing efficiency and the three best for potassium dissolution were found by measuring zones of solubilization on agar plates. Those isolates were characterized based on their 16S r RNA sequencing. This research clearly indicates that soil microorganisms play an important role in the availability of nutrients to plates, and provides a way for this dependence on chemical fertilizers to decrease.