title: Isolation and characterization of a novel biosurfactant produced by hydrocarbon-degrading bacterium Alcanivorax dieselolei B-5.
abstract: OBJECTIVE
  Our goal was to identify a novel biosurfactant produced by a marine oil-degrading bacterium.
  
  
  RESULTS
  Biosurfactants were produced by Alcanivorax dieselolei strain B-5(T) growing with diesel oil as the sole carbon and energy source. Culture supernatant was first extracted with chloroform/methanol (1:1, v/v), then further purified step by step with a normal phase silica gel column, a Sephadex LH20 gel column and a preparative thin layer plate. The main component was determined to be a lipopeptide; it was chemically characterized with nuclear magnetic resonance, liquid chromatography-quadrupole ion-trap mass spectrometry, amino acid analysis and GC-MS and was found to be a mixture of proline lipids. The monomers of the proline lipids were composed of a proline residue and a fatty acid (C(14:0), C(16:0) or C(18:0)). The critical micelle concentration of the mixed proline lipids was determined to be 40 mg l(-1). Moreover, activity variations in ranges of pH, temperature and salinity were also detected and showed reasonable stability.
  
  
  CONCLUSIONS
  Alcanivorax dieselolei B-5 produced a novel linear lipoamino biosurfactant, characterized as a proline lipid.
  
  
  CONCLUSIONS
  A proline lipid was characterized for the first time as a bacterial biosurfactant. This product has potential in both environmental and industrial applications.
authors.affiliation: Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State Oceanic Administration, Xiamen, China.
authors.forename: N
authors.initials: N
authors.lastname: Qiao
authors.forename: Z
authors.initials: Z
authors.lastname: Shao
mesh_terms: D053521:Alcanivoraceae / Q000737:chemistry* / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D006838:Hydrocarbons / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008055:Lipids / Q000737:chemistry; D055666:Lipopeptides / Q000737:chemistry; D013501:Surface-Active Agents / Q000302:isolation & purification* / Q000378:metabolism; D013696:Temperature
chemical_list: D000596:Amino Acids; D006838:Hydrocarbons; D008055:Lipids; D055666:Lipopeptides; D013501:Surface-Active Agents