Identification and ultra‐high‐performance liquid chromatography coupled with high‐resolution mass spectrometry characterization of biosurfactants, including a new surfactin, isolated from oil‐contaminated environments

Abstract

SummaryBiosurfactant‐producing bacteria were isolated from samples collected in areas contaminated with crude oil. The isolates were screened for biosurfactant production using qualitative drop‐collapse test, oil‐spreading and emulsification assays, and measurement of their tensoactive properties. Five isolates tested positive for in the screening experiments and displayed decrease in the surface tension below 30 mN m−1. The biosurfactants produced by these isolates were further investigated and their molecular identification revealed that they are bacteria related to the Bacillus genus. Additionally, the biosurfactants produced were chemically characterized via UHPLC‐HRMS experiments, indicating the production of surfactin homologues, including a new class of these molecules.

Soil Bacteria Isolated From Tunisian Arid Areas Show Promising Antimicrobial Activities Against Gram-Negatives

“…Surfactin possesses a number of biological activities. It is known for its antiviral, antibacterial and antitumoral properties ( Meena and Kanwar, 2015 ; Moro et al, 2018 ).…”

High-Frequency Occurrence of Surfactin Monomethyl Isoforms in the Ferment Broth of a Bacillus subtilis Strain Revealed by Ion Trap Mass Spectrometry

“…During the spectral evaluation of the surfactin components, in certain cases, extraordinary mass differences were observed between the b 5 and b 4 fragment ions, which indicated that there is a possibility for the replacement of the common Asp amino acid residue in the fifth position at certain surfactin variants. This observation led to the detection of the monomethyl ester surfactins containing AME instead of Asp in the fifth position of the peptide chain according to the detected mass difference between the b-series ions ( Figure 3 ) [ 9 ]. This difference of the fragmentation patterns could be compared with each other between the [Sur] and the [AME5] type surfactins possessing same molecular weight ( Figure 3 ).…”

“…Although most of these variants were reported in the 1990s, a recent study from our group introducing a novel surfactin molecule containing Val in the second amino acid position [ 6 ] ( Figure 1 ) proved that there may still be surfactin isoforms that are yet to be discovered. Moreover, the incorporations of esterified form of Asp (Asp- O -Me, aspartic acid 4-methyl ester—AME) and Glu (Glu- O -Me, glutamic acid 5-methyl ester—GME) were also reported occasionally [ 7 , 8 , 9 ]. In the present study, an HPLC gradient elution method was applied that was capable of separating all lipopeptide components in our sample and to examine the separated, previously hidden, more non-polar fractions by MS 2 measurements in order to identify the various surfactin molecules, with different amino acid sequences and aliphatic acid chain lengths, produced by B. subtilis SZMC 6179J to the full extent.…”

The Potential Applications of Bacillus sp. and Pseudomonas sp. Strains with Antimicrobial Activity against Phytopathogens, in Waste Oils and the Bioremediation of Hydrocarbons

“…The supernatants used in experiments were sterilized for 30 min at 115 • C, and after sterilization, no significant changes were registered in the emulsification activity. Many authors mention that some biosurfactants are heat resistant [44], while some are not, and the main criterion in their tests was verifying the emulsification activity after autoclaving the samples [45]. The antimicrobial activity of the biosurfactants was evaluated using the agar diffusion method against the aforementioned phytopathogens.…”