Isolation of phosphate solubilizing bacteria from acacia tree rhizophere soil

Phosphorous is an essential plant nutrient whose deficiency severely restricts crop yield and it is the least available nutrient to plants. Phosphate solubilizing bacteria play an essential role in the phosphorus nutrition cycle by enhancing its availability to plants through release from inorganic and organic soil phosphate pools. In this study, we sought to isolate phosphate solublizing bacteria (PSB) from soil of the Acacia plant rhizophere. Candidate colonies were grown on National Botanical Research Institute’s phosphate (NBRIP) screening medium with 0.5% tricalcium phosphate (TCA) to determine phosphate liberation capabilities. The colonies were tested to temperatures (270 C, 370 C, 470 C and 570 C) and pH (from 4 to 9) compatibility, as well as heavy metal exposure (0- 0.12 μg/ml HgCl(II)). We learned that PSB colonies isolated from the Acacia plant rhizophere soil demonstrated high phosphate liberating activity (on NBRIP medium containing TCA) and survived temperatures to 470C over a pH range of 4.5 to 8.5, and up to .02 μg/ml HgCl(II). These results provide a strong baseline source for application in agriculture when a bio-fertilizeris required. Key words: Phosphate solubizing, Bacteria, Acacia, Tri-calcium-phosphate.