PHOSPHATE SOLUBILIZATION AND ORGANIC ACIDS PRODUCTION BY FLUORESCENT PSEUDOMONADS ASSOCIATED WITH POPULUS NIGRA RHIZOSPHERE

Keywords: bacterium, hydroxyapatite, poplar, rhizosphere, tricalcium phosphate

Abstract

Application of phosphobacteria (PSB) has been noticed as the best eco-friendly method for plant P nutrition. For this purpose, PSB isolates were initially screened from the rhizosphere of Populus nigra by Sperber medium. Out of 138 isolates, 25 were found to belong to fluorescent pseudomonads based on screening with King's B+++ medium. Three superior isolates, FRPF4, FRPF6, and FRPF12, were evaluated for their potential to solubilize tricalcium phosphate (TCP) and hydroxyapatite (HAP), quantitatively and qualitatively. Maximum solubilized TCP (454.6±12.6µg/mL) and HAP (126.0±3.6µg/mL) belonged to FRPF4 on the 8th day of incubation (p£0.05). Phosphate solubilization was also accompanied by a gradual decrease in Pikovskaya’s broth acidity from 7 to 4.2 during the incubation. Aspartic acid along with three (fumaric, citric, and maleic acids) out of eight tested organic acids were detected in all the bacterial filtrates through HPLC analysis. However, nicotinic acid was only found in FRPF4 and FRPF6 filtrates. So, the possible P solubilization mechanisms of the isolates were to decreasing the media acidity as well as producing various organic acids. Finally, further studies under in vivo conditions should be conducted to test the feasible use of such beneficial rhizobacteria as biofertilizer in black poplar cultivation

Published
2021-05-20
How to Cite
Samavat, S., & Rahimifard, M. (2021). PHOSPHATE SOLUBILIZATION AND ORGANIC ACIDS PRODUCTION BY FLUORESCENT PSEUDOMONADS ASSOCIATED WITH POPULUS NIGRA RHIZOSPHERE. Journal of Applied Biological Sciences, 15(2), 196-205. Retrieved from http://jabsonline.org/index.php/jabs/article/view/850
Section
Articles