Isolation and Screening of Zinc and Potassium Solubilizing Microorganisms from Different Rhizospheric Soil

Abstract

Zinc is considered as a crucial trace micronutrient for proper growth, reproduction and driving of many metabolic reactions in all crops. Potassium is classified as a macronutrient associated with movement of water and nutrients as well as enzyme activation. The present study was aimed for isolation and screening of zinc and potassium solubilizing microorganisms from different rhizospheric soil of rice. Eight different isolates- ZSB1, ZSB2, ZSB3, ZSB4, KSB1, KSB2, KSB3 and KSB4 were obtained and were screened for their Zinc and Potassium solubilizing activities on TRIS minimal agar medium and Aleksandrov’s medium, respectively. Upon characterization, ZSB1, ZSB4 and KSB3 were observed as motile Gram-negative organisms, ZSB2, KSB2 and KSB4 as motile Gram-positive organisms while ZSB3 and KSB1 had mycelial growth with some conidial spore. All isolates gave positive results for starch and lipid hydrolysis. In gelatin hydrolysis, only ZSB3, ZSB4, KSB1 and KSB2 gave positive results. The main purpose to obtain these zinc and potassium solubilizing microorganisms was for their use in plant growth promotion as biofertilizers to increase soil fertility and crop yield.