Effect of Thymus ciliatus oil-based disinfectant solutions against bio-films formed by Bacillus cereus strains isolated from pasteurized-milk processing lines in Algeria

Authors

  • Amina Kalai Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria
  • Fadila Malek Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria
  • Leila Bousmaha-Marroki University Djilali Liabes-Sidi Bel Abbes 22000, Algeria

DOI:

https://doi.org/10.38150/sajeb.8(1).p01-12

Abstract

Bacillus cereus is a foodborne pathogen that often persists in dairy environments and is associated with food poisoning and spoilage. This spore-forming bacterium has a high propensity to develop biofilms onto dairy processing equipment and resists to chemical cleaning and disinfecting. This study deals with the in vitro application of thyme oil-based sanitizer solutions against biofilms formed by B. cereus genotypes which persist in pasteurized-milk processing lines. The effect of Thymus ciliatus essential oil on B. cereus planktonic cells and biofilms was assessed. The oil was tested alone and in combination with organic acids or industrial cleaning agents, in order to improve the removal of B. cereus recurrent genotypes. Minimal inhibitory concentrations of planktonic growth (MICs), biofilm formation (MBIC) and biofilm eradication (MBEC) of oil and organic acids were evaluated by microdilution assays. Thyme oil was more effective than organic acids against B. cereus planktonic growth, biofilm formation and established bio-films. High values of MICs were obtained for the three organic acids tested (3.5-4.5%) in comparison with those of essential oil (0.082-0.088%). The combination of oil with other antimicrobials as acetic acid, NaOH or HNO3 improves their effectiveness against B. cereus biofilms. These oil-based sanitizer solutions allow complete B. cereus biofilm eradication and should be an attractive candidate for the control and removal of biofilms in the dairy envi-ronment.

Author Biographies

Amina Kalai, Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria

Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria

Fadila Malek, Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria

Department of Biology, Faculty SNV-STU, University of Tlemcen, Tlemcen 13000, Algeria

Leila Bousmaha-Marroki, University Djilali Liabes-Sidi Bel Abbes 22000, Algeria

Microbiology and natural product Group, Plant Biodiversity Laboratory: valorisation and conservation, Faculty of Natural Sciences, University Djilali Liabes-Sidi Bel Abbes 22000, Algeria

Downloads

Published

2018-10-29

Issue

Section

Research Articles