The effect of biofilm forming some lactic acid bacteria isolated from sourdough on Bacillus subtilis

In this study, characteristics of biofilm formation of 24 lactic acid bacteria isolated from ten different sourdough samples were investigated and antimicrobial effects of biofilms of lactic acid bacteria on Bacillus subtilis known as a rope factor on bread were determined. Microtiter plates method was used for biofilm formation and antimicrobial assays.It was determined that all lactic acid bacteria strains isolated from sourdough samples formed biofilms and count of adherent lactic acid bacteria cells in biofilms increased from 104 cfu/mL up to 109 cfu/mL. It was also reported that lactic acid bacteria biofilms showed antimicrobial effect on Bacillus subtilis. When logarithmic graphics were examined for a decrease in Bacillus subtilis levels, the highest antimicrobial effect with 6 log decrease on the number of Bacillus subtilis were obtained by the biofilms of lactic acid bacteria strains of TT4, TT3, and T8. Meanwhile, strains of TT15, TT14, TT8-1 showed the lowest antimicrobial effect with 2 log decrease.