Low-Dose Electron-Beam Irradiation for the Improvement of Biofilm Formation by Probiotic Lactobacilli

The effects of 50-150 gray electron-beam irradiation on the biofilm-formation ability and cell surface hydrophobicity of the commercial strain,Lactobacillus acidophilusDDS (R)-1, from Lacto-G (a marketed synbiotic formulation) and the putative probiotic,L. rhamnosusVahe, were evaluated. No significant changes in cell surface hydrophobicity were found after irradiation, while increases in biofilm-formation abilities were documented for both investigated microorganisms 0.22 +/- 0.03 vs. 0.149 +/- 0.02 (L. rhamnosusVahe, 150 Gy) and 0.218 +/- 0.021 vs. 0.17 +/- 0.012 (L. acidophilusDDS (R)-1, 150 Gy). Given this, the use of electron-beam irradiation (50-100 Gy) for the treatment ofL. rhamnosusVahe andL. acidophilusDDS (R)-1 cells may be considered in product sterilization, quality improvement, and packaging practices.