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Structural characterization of a rhamnolipid-type biosurfactant produced by Pseudomonas aeruginosa MR01: Enhancement of di-rhamnolipid proportion using gamma irradiation

Lotfabad, T. B ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1016/j.colsurfb.2010.06.026
  3. Publisher: 2010
  4. Abstract:
  5. We previously reported that MR01, an indigenous strain of Pseudomonas aeruginosa, was able to produce a rhamnolipid-type biosurfactant. Here, we attempted to define the structural properties of this natural product. The analysis of the extracted biosurfactant by thin-layer chromatography (TLC) revealed the presence of two compounds corresponding to those of authentic mono- and di-rhamnolipid. The identity of two structurally distinguished rhamnolipids was confirmed by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy. Liquid chromatography/mass spectrometry (LC/MS) of extracted biosurfactant revealed up to seventeen different rhamnolipid congeners. Further quantification showed di-rhamnolipids as the major compound (77.2%), while monorhamnolipids comprising a smaller proportion (22.8%) of MR01 biosurfactant. Rha-Rha-C10-C10 was verified as the major component of the MR01 biosurfactant (35.93%). Cytotoxic activity of MR01 biosurfactant against human cancer Hela cells showed an excellent inhibitory effect of 5μg/ml. An isolated mutant strain (MR01-C) created by Gamma ray irradiation demonstrated more than one and a half-fold biosurfactant production and activity compared with the parent strain. Analysis of the biosurfactant produced by MR01-C showed the magnitude of di-rhamnolipids in the sample increased up to 88.6% (∼15% higher than control) and the quantity of Rha-Rha-C10-C10 increased to 52.08% (∼45% higher than control)
  6. Keywords:
  7. Di-rhamnolipid ; Gamma irradiation ; Monorhamnolipid ; Pseudomonas aeruginosa MR01 ; Rhamnolipid ; Bio surfactant ; Biosurfactant production ; Cytotoxic activities ; Gamma-ray irradiation ; HeLa cell ; Human cancer ; Indigenous strain ; Inhibitory effect ; Isolated mutants ; Liquid chromatography/mass spectrometry ; Natural products ; Parent strain ; Pseudomonas aeruginosa ; Rhamnolipids ; Structural characterization ; Biomolecules ; Irradiation ; Nuclear magnetic resonance ; Nuclear magnetic resonance spectroscopy ; Resonance ; Surface active agents ; Thin layer chromatography ; Gamma rays ; Soybean oil ; tetrazolium ; Acid precipitation ; Bacterial strain ; Bacterium culture ; Bioassay ; Cancer cell culture ; carbon nuclear magnetic resonance ; Carbon source ; Controlled study ; Cytotoxicity ; Liquid chromatography ; Minimum inhibitory concentration ; Nonhuman ; Priority journal ; Protein structure ; Proton nuclear magnetic resonance ; Structure analysis ; Transmission electron microscopy ; Animals ; Antineoplastic Agents ; Cell Proliferation ; Cercopithecus aethiops ; Drug Screening Assays, Antitumor ; Escherichia coli ; Glycolipids ; Hela Cells ; Humans ; Magnetic Resonance Spectroscopy ; Mass Spectrometry ; Microbial Sensitivity Tests ; Molecular Structure ; Staphylococcus aureus ; Structure-Activity Relationship ; Vero Cells
  8. Source: Colloids and Surfaces B: Biointerfaces ; Volume 81, Issue 2 , 2010 , Pages 397-405 ; 09277765 (ISSN)
  9. URL: http://www.sciencedirect.com/science/article/pii/S0927776510003577