Figure 1
L. casei BL23 releases lipid components of high molecular weight in the supernatant with antibiofilm properties. (a) S. Enteritidis was grown in polystyrene microplates and treated with multiple fractions of L. casei cell-free supernatant (LC-CFS) and MRS medium (MRS). After 24 h of culture, the biofilms were quantified by crystal violet staining. The LC-CFS and MRS medium were fractionated by size-exclusion ultrafiltration, generating fractions with molecular weight ranging from 3 kDa to over 100 kDa. (b) The LC-CFS fractions exhibiting an antibiofilm activity and the corresponding MRS fractions were treated with a lipid adsorption matrix to selectively remove all the lipids. Biofilm biomasses of S. Enteritidis were then quantified by crystal violet staining after treatment with the fractions in the absence (Lipid −) and in the presence (Lipid +) of lipids. (c) S. Enteritidis biofilm formation was quantified after treatment with live L. casei. Please note that the control condition “L. casei” shows the biomass formed by L. casei BL23 in TSB without S. Enteritidis. (d) S. Enteritidis biofilm formation was quantified after treatment with lysed L. casei. All the results were normalized to the untreated conditions and expressed as a percentage.
