Characterization and Antibacterial Activity of a Glycoside Antibiotic from Streptomyces variabilis PO-178

  • PTR Kekuda
  • R Onkarappa
  • ND Jayanna


In the present study, characterization and antibacterial activity of a glycoside antibiotic from fermentation broth of bioactive Streptomyces variabilis PO-178 recovered previously from Western Ghat soil of Agumbe, Karnataka, India was investigated. Mass cultivation of the strain PO-178 was carried out in Starch casein nitrate broth. The fermentation broth was extracted using butanol solvent in a separation funnel. The concentrated butanol extract was subjected to chromatographic techniques viz., thin layer and silica gel column chromatography for purification of bioactive components. Out of 3 fractions (A, B and C) obtained, only one fraction (C) displayed inhibitory activity against Staphylococcus aureus and Pseudomonas aeruginosa. The bioactive fraction C was subjected to spectral analysis (LC-MS, IR, 1H-NMR and 13C-NMR) in order to determine the structure. On the basis result of spectral analysis, the purified fraction was predicted as a glycoside antibiotic with molecular weight 514 and molecular formula C24H34O12. The antibiotic displayed marked inhibitory activity against S. aureus as revealed by wider zones of inhibition and low minimum inhibitory concentration value.

Journal Identifiers

eISSN: 2305-3372
print ISSN: 2226-7522