Lipopeptides from Bacillus subtilis GM5 Inhibit Biofilm Formation by Staphylococcus epidermidis through Regulation of Gene Expression.

We studied the effect of the total lipopeptide fraction from Bacillus subtilis GM5 on biofilm formation by the opportunistic pathogen Staphylococcus epidermidis and on the expression of genes involved in biofilm formation. Scanning electron microscopy showed that the total lipopeptide fraction of B. subtilis GM5 inhibits biofilm formation by S. epidermidis ATCC 14990, reduces bacterial adhesion to glass, and causes bacterial deformation. Gene expression analysis using RT-qPCR demonstrated that cell treatment with the total lipopeptide fraction suppressed the expression of genes involved in biofilm formation by 2.8 (sarA) and 3 times (icaA), which correlated with the inhibition of biofilm formation.