Isolation of Phosphate-Solubilizing Bacteria from Different Fields Crop Productions

There are many factors involved in the availability of P through phosphatases efficiency such as the microbial fauna, soil temperature, bacteria communities, plant physiological state, type of rooting system, age of the plant and the location of ectomycorrhiza on the root. To assess the effects of different crop productions on the diversity and the efficiency of phosphate-solubilizing bacteria (PSB), this study isolated phosphate-solubilizing bacteria from paddy fields and eggplant fields before and after harvest in Kochi prefecture in Japan. The results showed that a total of 9 heterotrophic bacterial isolates present different degrees of mineral tri-calcium phosphate (Ca3(PO4)2)- solubilizing activities. Klebsiella pneumonia in the paddy field with water and in the eggplant fields which solubilize Ca3(PO4)2 better than FePO4 and AlPO4. Especially, Klebsiella pneumoniae strain M-AI-2 and Gluconacetobacter sp. isolate code Ek01 in the eggplant fields seem to have the capacity to solubilize insoluble forms of AlPO4 and FePO4 which are the main forms of insoluble phosphates in acid sandy soils.