Structural characterization of lipopeptides from Brevibacillus brevis HOB1.
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 C(13)-C(15) beta-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 (C(15) surfactin) exhibited a good surface activity of 26.8 mN/m with CMC of 9 x 10(-6 )M. Surfactin is a powerful biosurfactant possessing biological activities. As far as we know, Br. brevis is a new surfactin-producing species.
Wang
Ji
J
State Key Laboratory of Bioreactor Engineering and Institute of Applied Chemistry, East China University of Science and Technology, Shanghai 200237, China.
Haddad
Namir I A
NI
Yang
Shi-Zhong
SZ
Mu
Bo-Zhong
BZ
D000595:Amino Acid Sequence; D056449:Bacillales / Q000737:chemistry*; D055666:Lipopeptides / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism; D021241:Spectrometry, Mass, Electrospray Ionization; D013500:Surface Tension; D053719:Tandem Mass Spectrometry
D055666:Lipopeptides