Abstract

In the present study, Pseudoxanthomonas species was isolated from rhizosphere soil samples of selected two medicinal plants such as Alternenthera sessilis Linn. and Leucas aspera (Wild) Linn., which were collected from agricultural fields at kundagol, Dharwad, Karnataka. Pseudoxanthomonas sp. is gram negative, aerobic, motile, non-spore forming rod shaped bacterium and it was designated as Pseudoxanthomonas strain RSA-23, it was found to possess broad spectrum of antimicrobial activity against pathogenic microorganisms. Further the most potent strain RSA-23 was characterized by physiological, biochemical and 16S ribosomal RNA gene sequencing. The 16S ribosomal RNA gene sequencing and analysis of phylogenetic tree showed 100% sequence similarity with Pseudoxanthomonas indica (KT204489). The methanol extract of Pseudoxanthomonas strain RSA-23 was analyzed through UV-spectroscopy and Fourier transform infrared spectroscopy (FTIR), The UV-Vis. spectra revealed the presence of indole and the presence of different functional groups such as aldehydes, amines and alkyl halides were indicated by FTIR spectra.

Key words: Key Words: Pseudoxanthomonas sp, Rhizosphere soil, Antimicrobial activity, FTIR, 16S rRNA gene sequencing.