title: Characterization of a new lipopeptide surfactant produced by thermotolerant and halotolerant subsurface Bacillus licheniformis BAS50.
abstract: Strain BAS50, isolated from a petroleum reservoir at a depth of 1,500 m and identified as Bacillus licheniformis, grew and produced a lipopeptide surfactant when cultured on a variety of substrates at salinities of up to 13% NaCl. Surfactant production occurred both aerobically and anaerobically and was optimal at 5% NaCl and temperatures between 35 and 45 degrees C. The biosurfactant, termed lichenysin A, was purified and chemically characterized. A tentative structure and composition for the surfactant are described. Lichenysin A is a mixture of lipopeptides, with the major components ranging in size from 1,006 to 1,034 Da. The lipid moiety contains a mixture of 14 linear and branched beta-hydroxy fatty acids ranging in size from C12 to C17. There are seven amino acids per molecule. The peptide moiety is composed of the following amino acids: glutamic acid as the N-terminal amino acid, asparagine, valine, leucine, and isoleucine as the C-terminal amino acid, at a ratio of 1.1:1.1:1.0:2.8:1.0, respectively. Purified lichenysin A decreases the surface tension of water from 72 mN/m to 28 mN/m and achieves the critical micelle concentration with as little as 12 mg/liter, characterizing the product as a powerful surface-active agent that compares favorably to others surfactants. The antibacterial activity of lichenysin A has been demonstrated.
authors.affiliation: Technical University of Braunschweig, Germany.
authors.forename: M M
authors.initials: MM
authors.lastname: Yakimov
authors.forename: K N
authors.initials: KN
authors.lastname: Timmis
authors.forename: V
authors.initials: V
authors.lastname: Wray
authors.forename: H L
authors.initials: HL
authors.lastname: Fredrickson
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D001407:Bacillus / Q000737:chemistry* / Q000187:drug effects / Q000302:isolation & purification; D001419:Bacteria / Q000187:drug effects; D004734:Energy Metabolism; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D008074:Lipoproteins / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008823:Micelles; D008826:Microbial Sensitivity Tests; D010456:Peptides, Cyclic / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010578:Petroleum; D012988:Soil Microbiology; D013500:Surface Tension; D013501:Surface-Active Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology
chemical_list: D000596:Amino Acids; D000900:Anti-Bacterial Agents; D005227:Fatty Acids; D008074:Lipoproteins; D008823:Micelles; D010456:Peptides, Cyclic; D010578:Petroleum; D013501:Surface-Active Agents; C094325:lichenysin A