Structural and immunological characterization of a biosurfactant produced by Bacillus licheniformis JF-2.
Bacillus licheniformis JF-2 produces a very active biosurfactant under both aerobic and anaerobic conditions. We purified the surface-active compound to homogeneity by reverse-phase C18 high-performance liquid chromatography and showed that it is a lipopeptide with a molecular weight of 1,035. Amino acid analysis, fast atom mass and infrared spectroscopy, and, finally, 1H, 13C, and two-dimensional nuclear magnetic resonance demonstrated that the biosurfactant consists of a heterogeneous C15 fatty acid tail linked to a peptide moiety very similar to that of surfactin, a lipopeptide produced by Bacillus subtilis. Polyclonal antibodies were raised against surfactin and shown to exhibit identical reactivity towards purified JF-2 lipopeptide in competition enzyme-linked immunosorbent assays, thus providing further evidence for the structural similarity of these two compounds. Under optimal conditions, the B. licheniformis JF-2 biosurfactant exhibits a critical micelle concentration of 10 mg/liter and reduces the interfacial tension against decane to 6 x 10(-3) dyne/cm, which is one of the lowest interfacial tensions ever reported for a microbial surfactant.
Lin
S C
SC
Department of Chemical Engineering, University of Texas at Austin, 78712.
Minton
M A
MA
Sharma
M M
MM
Georgiou
G
G
D000595:Amino Acid Sequence; D000907:Antibodies, Bacterial; D001407:Bacillus / Q000737:chemistry / Q000276:immunology / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000276:immunology; D005227:Fatty Acids / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007120:Immunochemistry; D055666:Lipopeptides; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D015394:Molecular Structure; D008970:Molecular Weight; D010456:Peptides, Cyclic; D017386:Sequence Homology, Amino Acid; D013501:Surface-Active Agents / Q000737:chemistry / Q000378:metabolism*
D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D005227:Fatty Acids; D055666:Lipopeptides; D010456:Peptides, Cyclic; D013501:Surface-Active Agents; C009365:surfactin peptide