Isolation, in vitro screening and characterization of native phosphate and potash solubilizing bacterial isolates from Malnad region of Karnataka

Abstract

In the present study as many as 45 soil samples were collected from different crop rhizosphere (banana, maize, ginger and tobacco) for isolation of phosphorous and potassium solubilizing bacteria and out of 45 samples collected eight potash and seven phosphorus solubilizing bacterial isolates were isolated by standard serial dilution pour plate technique and all the isolates were characterized based on the morphological and biochemical characteristics as Bacillus sp. Further when all the isolates screened for the potassium and phosphorous ability in the in vitro experiments. Out of 8 potassium solubilizing bacterial isolates the isolate number KSB – 6 showed the maximum zone of solubilization of mica on Alexandrove’s media (2.40cm) and also released 55.49 (mg/ml) of potassium at 10th day after inoculation. Similarly, out of seven phosphorus solubilizing bacterial isolates screened the isolate number PSB – 3 showed maximum zone of solubilization of phosphorus 2.20 cm on the Sperber’s media and released an amount of 9.50% of inorganic phosphorus at 10th days after inoculation. Scale of studies are required to develop and evaluate efficient potassium solubilizing Bacillus sp. KSB - 6 and phosphorous solubilizing PSB - 5 bacterial consortia green house and under field conditions using different crops.