Evaluation of media for isolation and screening of silicate solubilising bacteria

Silicate solubilising bacteria (SSB) are used as biofertilizer to crops as it solubilises silica and potassium from soil silicate minerals. The investigators use different types of media containing an insoluble silicate mineral of their choice to determine the solubilisation potential of the isolates. However no specific medium is recommended either for isolation or for enumeration and screening. In the present study nutrient agar, Bunt and Rovira medium, Soil extract agar and Glucose agar medium containing 0.25% magnesium trisilicate were compared for their suitability for isolation, enumeration and screening. Soil extract agar medium containing 0.25% magnesium trisilicate is more ideal for enumeration based on the growth and clarity of dissolution zone while for screening the isolates plain glucose medium with 0.25% magnesium trisilicate is ideal as there is rapid solubilisation and clearing larger zone.