Investigation of the effect of biosurfactant of Bacillus subtilis against Staphylococcus strains biofilms

Biosurfactants are compounds that are produced by different microorganisms and have an emulsifying property. This study aimed to investigate extractive biosurfactant from bacillus subtilis (PTCC1720) against the biofilms of Staphylococcus aureus (PTCC 1112), Staphylococcus saprophyticus (PTCC 1440) and Staphylococcus epidermidis (PTCC 1435). This study was conducted in vitro to examine the effect of biosurfactant produced by Bacillus subtilis in prevention of biofilm formation and removal of biofilms produced by different staphylococcal species. First, bacillus subtilis was cultured in suitable culture media for producing biosurfactant. Then, extraction of produced biosurfactant was done and anti-biofilm properties were assessed by determination of optical density at 570 nm by ELISA reader equipment. Statistical analysis was performed by SPSS software version 16 and ANOVA. The means were compared at 95% confidence level by Duncan's method. According to the results, the biosurfactant produced by bacillus subtilis had emulsification index equal to 40% and oil replacement area was 1.8 ± 0.3 cm-2. Produced biosurfactant by bacillus subtilis had a significant effect on preventing microbial formation with the highest effect on biofilm of staphylococcus aureus and Staphylococcus saprophyticus. Also, the results showed that the biofilm of staphylococcus epidermidis had the highest resistance in this respect. According to this study, the antibiofilm activity of biosurfactant extracted from Bacillus subtilis against the biofilm of staphylococcus aureus, epidermidis and saprophyticus was shown. In addition, this type of biosurfactant can be effective in removing biofilms formed by staphylococcal strains.