Gibbs free energy of adhesion of Bacillus cereus isolated from dairy plants on different food processing surfaces evaluated by the hydrophobicity

Abstract

SummaryAdhesion of Bacillus cereus A6 and L1, isolated from dairy plants, to stainless steel, granite, and glass surfaces was evaluated. Adhesion of B. cereus to all surfaces was affected by hydrophobicity. Adhesion to the hydrophobic surfaces (ΔGswsTOT < 0) of granite and stainless steel was greater than adhesion to glass, which was classified as a hydrophilic surface (ΔGswsTOT > 0). Bacillus cereus A6 adhered in higher numbers to all three surfaces evaluated and was less hydrophilic (ΔGbwbTOT = 19.83) than B. cereus L1 (ΔGbwbTOT = 23.50). For instance, in stainless steel the number of adhered cells of B.cereus A6 was 2.42 log CFU cm−2 while to B. cereus L1 was 1.96 log CFU cm−2. The adhesion of B. cereus was thermodynamically favourable in granite and stainless steel surface (ΔGadhesion < 0). Therefore, the adherence process was affected by the strain of B. cereus and by the hydrophobicity of stainless steel, granite, glass and microorganisms surfaces.