Objective(s): The multi-drug resistant bacteria and clinical infections are some of the biggest global
concerns, so new drugs are needed. Antimicrobial peptides and lipopeptides are new bioactive agents
with great potential that can become a new strategy for clinical applications.
Materials and Methods: Some Bacillus strains were isolated based on hemolytic antimicrobial
production from the soil. The extracellular proteins were extracted by acidic precipitation and
chloroform/methanol method and analyzed by SDS-PAGE electrophoresis and stained with Sudan
black. The black fragment was purified and characterized by FTIR, GC/MS, and HPLC analysis to
demonstrate the presence of lipids and proteins. The anti-microbial ability and stability of the purified
lipopeptide were assayed by the Kirby-Bauer method. Also, it was examined for metal removal.
Results: A new Bacillus halotolerans strain SCM 034 with hemolytic antimicrobial production was
isolated. According to GC/MS (detecting C16, C17) and HPLC (detecting leucine, glutamic acid, valine,
arginine, glycine, and aspartic acid) data, the black fragment was lipopeptide. Polyacrylamide hydrogel
containing lipopeptide and gel purified lipopeptide showed anti-microbial activities against S. aureus
and S. cerevisiae that were stable for a few months. Also, the lipopeptide was useful for cation removal
and decreased cobalt, nickel, and calcium by 10.81 %, 24.39 %, and 34 %, respectively.
Conclusion: Production of antibacterial lipopeptide hemolysin from this strain is reported for the
first time and according to the results, lipopeptides have unique properties with biomedical and
pharmaceutical applications. Also, polyacrylamide hydrogel lipopeptide is a promising candidate for
wound healing.
