Structural Characterization of Lipopeptides from Brevibacillus brevis HOB1

• Published in: Applied biochemistry and biotechnology 2010-02, Vol.160 (3), p.812-821
• Main Authors: Wang, Ji, Haddad, Namir I. A, Yang, Shi-Zhong, Mu, Bo-Zhong
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Amino acids; Bacillales - chemistry; Bacteria; Biochemistry; Biological and medical sciences; Biotechnology; Brevibacillus brevis; Chemistry; Chemistry and Materials Science; Chromatography; Fundamental and applied biological sciences. Psychology; Gas chromatography; Ionization; Lipopeptides - chemistry; Lipopeptides - isolation & purification; Lipopeptides - metabolism; Liquid chromatography; Mass spectrometry; Oil and gas fields; Peptides; Spectrometry, Mass, Electrospray Ionization; Surface Tension; Surfactants; Tandem Mass Spectrometry
• ISSN: 0273-2289; 1559-0291
• DOI: 10.1007/s12010-009-8536-9

Brevibacillus brevis HOB1 was isolated from the formation water of an oil field and found to produce lipopeptides. The separation of lipopeptides was successfully achieved by reversed-phase high-performance liquid chromatography (HPLC) leading to nine separated peaks. The chemical structures of these lipopeptides were studied by means of electrospray ionization mass spectrometry (ESI-MS), gas chromatography-mass spectrometry (GC/MS), HPLC and electrospray ionization tandem mass spectrometry (ESI-MS/MS). As the results, all the lipopeptides had peptide parts with the same amino acid composition of Asp, Glu, Val, and Leu in the molar ratio 1:1:1:4, while the lipid part was composed of C₁₃-C₁₅ β-hydroxy fatty acids. As the sequence of fraction 1 was determined to be N-Glu-Leu-Leu-Val-Asp-Leu-Leu-C, the same as surfactin, they were proposed to be surfactin isoforms. Fraction 4 (C₁₅ surfactin) exhibited a good surface activity of 26.8 mN/m with CMC of 9 × 10⁻⁶ M. Surfactin is a powerful biosurfactant possessing biological activities. As far as we know, Br. brevis is a new surfactin-producing species.