Author(s): Manisha S Adwani, Tini S Pillai, SS Isokar and GS Rokade

Abstract: Potassium is essential macronutrient for plant growth and plays significant role in activation of several metabolic processes including protein synthesis, photosynthesis, enzymes, as well as in resistance to diseases. Potassium solubilizing microorganisms present in the soil helps to convert complex potassium present in soil into simple form and make them available to plants. Soil microorganisms helps to break down complex minerals present in soil either by secreting acid or base and convert it into simple form which helps to maintain the soil fertility and iron cycle in soil. The soil sample were collected from rhizospheric soil. Isolation of KSB were carried out by using serial dilution technique on selective media i.e. Aleksandrov media. The further purification and maintenance was done on Aleksandrov media. Two isolates were extracted and named as KSB1 and KSB2. In respect of morphological characteristics, both isolates showed a negative Gram reaction, whitish to yellowish colony colour and colony appearance of most of the KSB isolates showed raised, smooth and glistening with short and long rod shape bacteria. The KSB isolates showed positive reaction to methyl red test, acid production, KOH test and catalase test. One isolate was positive to Simmons citrate test whereas one isolate showed negative reaction. Casein hydrolysis, Voges-proskauer test, starch hydrolysis, indole production test and H2S test showed negative reaction. Based on zone of solubilization, KSB1 showed maximum zone (20.67 mm) and KSB2 showed minimum zone of solubilization (17.67 mm).

DOI: 10.33545/26174693.2024.v8.i5Sd.1174