LC/ESI-MS/MS characterisation of lipopeptide biosurfactants produced by the Bacillus licheniformis V9T14 strain.

Lipopeptide biosurfactants produced by the Bacillus licheniformis V9T14 strain showed an interesting anti-adhesion activity against biofilm formation of human pathogenic bacterial strains. The chemical characterisation of the crude extract of V9T14 strain was first developed through electrospray ionisation mass spectrometry (ESI-MS) and ESI-MS/MS direct infusions: two sets of molecular ion species belonging to the fengycin and surfactin families were revealed and their structures defined, interpreting their product ion spectra. The LC/ESI-MS analysis of the crude extract allowed to separate in different chromatogram ranges the homologues and the isoforms of the two lipopeptide families. The extract was then fractionated by silica gel chromatography in two main fractions, I and II. The purified biosurfactants were analysed through a new, rapid and suitable LC/ESI-MS/MS method, which allowed characterising the composition and the structures of the produced lipopeptides. LC/ESI-MS/MS analysis of fraction I showed the presence of C(13), C(14) and C(15) surfactin homologues, whose structures were confirmed by the product ion spectra of the sodiated molecules [M + Na](+) at m/z 1030, 1044 and 1058. LC/ESI-MS/MS analysis of fraction II confirmed the presence of two main fengycin isoforms, with the protonated molecules [M + H](+) at m/z 1478 and 1506 corresponding to C(17) fengycin A and C(17) fengycin B, respectively. Other homologues (C(14) to C(16)) were revealed and confirmed as belonging to fengycin A or B according to the retention times and the product ions generated, although with the same nominal mass. Finally, a relative percentage content of each homologue for both lipopeptides families in the whole extract was proposed.

Pecci Y ，Rivardo F ，Martinotti MG ，Allegrone G ... -  《-》

Identification of fengycin homologues from Bacillus subtilis with ESI-MS/CID.

Bie X ，Lu Z ，Lu F 《-》

ESI LC-MS and MS/MS characterization of antifungal cyclic lipopeptides produced by Bacillus subtilis XF-1.

Bacillus subtilis XF-1 (CGMCC No. 2357), a patent strain with good effects for controlling the clubroot of crucifer and many pathogenic fungi, was predicted to produce cyclic lipopeptide (CLP) antibiotics based on its genomic analysis. In this study, the CLPs were purified and determined with the following protocol: the supernatant of XF-1 cultivating mixture was firstly precipitated, then the precipitants were extracted with methanol and further separated by Sephadex LH-20 chromatography to test its antifungal activities. Fungi-inhibiting fractions were further characterized with LC/ESI-MS and LC/ESI-MS/MS. The results show that four molecular ion peaks [M+H]⁺ (m/z 1,464, 1,478, 1,492 and 1,506) from fungi suppression fraction were identified as fengycin A with fatty acid of C₁₆-C₁₉, fengycin B (C₁₄-C₁₇), fengycin C (C₁₅-C₁₈), fengycin D (C₁₅-C₁₈) and fengycin S (C₁₅-C₁₈). Fengycin C (C₁₅ and C₁₈), fengycin D (C₁₅, C₁₆ and C₁₈) and fengycin S (C₁₅, C₁₆ and C₁₈) were reported for the first time. The diversity of the fengycins that exist in this strain will help the elucidation of their biocontrol mechanisms.

Li XY ，Mao ZC ，Wang YH ，Wu YX ，He YQ ，Long CL ... -  《-》

Isolation and characterization of surfactin produced by Bacillus polyfermenticus KJS-2.

Kim KM ，Lee JY ，Kim CK ，Kang JS ... -  《ARCHIVES OF PHARMACAL RESEARCH》

[Isolation and identification of lipopeptides produced by Bacillus subtilis using high performance liquid chromatography and electrospray ionization mass spectrometry].

Chen H ，Wang L ，Yuan C ，Zheng Z ，Yu Z ... -  《-》