N Qiao1, Z Shao. 1. Key Laboratory of Marine Biogenetic Resources, The Third Institute of Oceanography, State Oceanic Administration, Xiamen, China.
Abstract
AIMS: Our goal was to identify a novel biosurfactant produced by a marine oil-degrading bacterium. METHODS AND 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. SIGNIFICANCE AND IMPACT OF THE STUDY: A proline lipid was characterized for the first time as a bacterial biosurfactant. This product has potential in both environmental and industrial applications.
AIMS: Our goal was to identify a novel biosurfactant produced by a marine oil-degrading bacterium. METHODS AND 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 prolinelipids. The monomers of the prolinelipids 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 prolinelipids 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 prolinelipid. SIGNIFICANCE AND IMPACT OF THE STUDY: A prolinelipid was characterized for the first time as a bacterial biosurfactant. This product has potential in both environmental and industrial applications.
Authors: Will A Overholt; Kala P Marks; Isabel C Romero; David J Hollander; Terry W Snell; Joel E Kostka Journal: Appl Environ Microbiol Date: 2015-11-06 Impact factor: 4.792