Journal of Pure and Applied MicrobiologyVol. 4 No. 2

Screening and Isolation of Phosphate Solubilizing Pseudomonas stutzeri (EGB3) from Gut of Earthworm (Eisenia foetida): Solubilization as Influenced by Organic Acids

N.D. Prasanna, K.Vijayalakshmi, S.K. Shaheen, K.P. Jyotsna, G. Revathi, P. Jayalakshmi & P. Devika

Department of Applied Microbiology, Sri Padmavathi Mahila University, Tirupati - 517 502, India.

Received on 14 April 2010 and accepted on 30 May 2010



Crops absorb phosphorous in the form of soluble orthophosphate ion. The solubility of phosphate is inhibited by the presence of iron and aluminium in acidic soils and calcium in neutral and alkaline soils. This leads to fixation of phosphorous, making it not available to crop plants. The phosphate solubilizing bacteria (phosphobacteria) secretes organic acids like Gluconic acid, Oxalic acid, Acetic acid etc., which act on insoluble phosphates and convert the same into soluble form, thus providing phosphorous to plant. An experiment was conducted for the detection of organic acids using HPLC technique. Results clearly indicates that Gluconic acid and Oxalic acids were produced by Pseudomonas stutzeri in PKVS media.

Keywords : Phosphate solubilization, Pseudomonas stutzeri, organic acids