Journal of Pure and Applied MicrobiologyVol. 9 No. 3

Isolation and Characterization of Novel Apple Rhizosphere Bacterium as Fungal Antagonist

Sheetal Rana1, Ranjna Sharma1, Y.P. Sharma2 and Mohinder Kaur3

1Dr. YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230 H.P., India. 2Department of Forest Products, College of Forestry, Dr. YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230 H.P., India. 3Department of Basic Sciences, College of Forestry, Dr. YS Parmar University of Horticulture & Forestry, Nauni, Solan-173230 H.P., India.

Received on 09 April 2015 and accepted on 16 June 2015

 

ABSTRACT

Strain An-F was isolated from the rhizosphere soil of replant site of apple orchard at Shimla district H.P. and identified as Pseudomonas aeruginosa on the basis of biochemical tests and by 16S rRNA sequences. This bacterium exhibits a broad-spectrum antifungal activity towards phytopathogenic fungi. The antifungal metabolite by An-F was extracted and characterized using TLC and HPLC (High pressure liquid chromatography). Production of siderophores, phosphatase, HCN, ammonia, indole-3-acetic acid (IAA), gibberellins and cytokinins in An-F were determined. The antifungal metabolite produced by An-F has been identiƻed as 2, 4-diacetylphloroglucinol on the basis of TLC and HPLC data. Present study reports the production of 2,4-diacetylphloroglucinol as well as IAA, gibberellins and cytokinins for the first time by a saprophytic P. aeruginosa strain An-F isolated from the replant site of apple. Because of the production of siderophore, growth hormone, protease and phosphatase and its innate fungicidal potential, this strain can be used as biofertilizer and antagonist against a range of phytopathogenic fungi.

Keywords : Replant site, Pseudomonas aeruginosa, 2, 4-Diacetylphloroglucinol, Biocontrol.