Isolation and identification of temperature tolerant phosphate solubilizing bacteria as a potential microbial fertilizer

In this study, TTPSB were isolated from soil samples treated for 16  h at 55 °C. Their phosphate solubilizing activity was either evaluated in solid media by forming a clear zone (halo) or in liquid media by quantification of the soluble phosphate in the growth medium. Five colonies (RPS4, RPS6, RPS7, RPS8 and RPS9) were identified to be able to form a halo and t wo of the isolates (RPS9 and RPS7) tolerated a temperature of 55 °C. With tricalcium phosphate (TCP) as the sole P-source, the phosphate solubilizing capacity of RPS9 and RPS7 was determined to be 563.8 and 324.1 mg P L−1 in liquid Sperber medium, respectively. Both bacterial isolates were identified asPantoea agglomerans by molecular and biochemical characterization. To be used as a microbial fertilizer a carrier system for the temperature tolerant bacteria consisting of rock phosphate, sulfur and bagasse was used. It could be established that the bacterial cell counts of the microbial fertilizers were acceptable for application after storage for 4  months at 28 °C. In a greenhouse experiment using pot cultures, inoculation of maize (S.C.704) with the microbial fertilizers in an autoclaved soil resulted in a significant effect on total fresh and dry weight of the plant root and shoot as well as on the P content of the root and shoot. The ef fects observed with RPS9 as a component of the microbial fertilizer on plant growth and P nutrition was comparable with the addition of 50% of recommended triple super...
Source: World Journal of Microbiology and Biotechnology - Category: Microbiology Source Type: research