Microbial assisted (Bacillus mojavensis) production of bio-surfactant lipopeptide with potential pharmaceutical applications and its characterization by MALDI-TOF-MS analysis

Abstract

Lipopeptides are a fascinating group of biosurfactants possess remarkable surface properties. Functional groups on the surface of these molecules can combine with other substances leading to obtain applicable materials. The aim of the present study is the isolation of an anionic lipopeptide- producing bacterium and verifying its potential for pharmaceutical applications. A Bacillus mojavensis strain capable of producing a great amount of lipopeptide biosurfactant was selected from a number of isolated Bacillus using oil spreading technique, blood agar hemolysis, drop collapsing assay, pH sensitivity and biuret test. Anionic extracellular lipopeptides compound was extracted using metal salt precipitation method and its properties were investigated by TLC, FTIR and SDS page. HPLC-amino acid analysis showed that negative- charge amino acids were dominant in the peptidyl part of the crude supernatant and purified anionic fraction. Furthermore Matrix-assisted laser desorption ionization time-of-flight tandem mass spectrometry (MALDI-TOF-MS) analysis was applied to detect the lipopeptides harvested from the most anionic fraction obtained from anion- exchange chromatography and the results revealed the presence of surfactin isoform in the extracted substance. The extracted lipopeptides showed surface tension reducing ability, antibacterial activity and lack of toxicity to PC12 and PBMC cells. Also with negative nature interacted with basic molecules to make new compounds, so these surfactants can be considered as a natural product with potential pharmaceutical applications.