Author(s): Lee SC, Kim SH, Park IH, Chung SY, Choi YL
Abstract Share this page
Abstract Bacillus amyloliquefaciens strain LP03 isolated from soil, produced an antagonistic compound that strongly inhibited the growth of plant-pathogenic fungi and a lipopeptide biosurfactant. Also, isolated strain LP03 had a marked crude oil-emulsifying activity as it developed a clear zone around the colony after incubation for 24 h at 37 degrees C. LP03 was identified as Bacillus amyloliquefaciens by analysis of partial 16 S rRNA gene and partial gyrA gene sequence. The lipopeptide was purified by acid precipitation of cell-free culture broth, extraction of the precipitates with methanol, silica gel column chromatography, and reverse-phase, high-pressure liquid chromatography. The purified biosurfactant was analyzed biochemical structure by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and electrospray ionization mass spectrometry/mass spectrometry (ESI-MS/MS). The masses of the two peaks were observed by HPLC chromatography. Their masses were determined to be 1,044 and 1,058 m/z with MALDI-TOF mass spectrometry. As constituents of the peptide and lipophilic part of the m/z 1,022.6, seven amino acids (Glu-Leu-Met-Leu-Pro-Leu-Leu) and beta-hydroxy-C13 fatty acid were determined by ESI-MS/MS. The lipopeptide of 1,022.6 Da differed from surfactins in the substitution of leucine, valine and aspartic acid in positions 3, 4, and 5 by methionine, leucine, and proline, respectively. Novel lipopeptide was designated as bamylocin A.
This article was published in Arch Microbiol
and referenced in Journal of Bioremediation & Biodegradation