Archives of Microbiology

, Volume 174, Issue 4, pp 233–238

Adaptation of the food-borne pathogen Bacillus cereus to carvacrol

Authors

  • Annemieke Ultee
    • Agrotechnological Research Institute (ATO-DLO), PO Box 17, 6700 AA Wageningen, The Netherlands
  • Edwin P.W. Kets
    • Agrotechnological Research Institute (ATO-DLO), PO Box 17, 6700 AA Wageningen, The Netherlands
  • Mark Alberda
    • Wageningen University, Laboratory of Plant Physiology, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands
  • Folkert A. Hoekstra
    • Wageningen University, Laboratory of Plant Physiology, Arboretumlaan 4, 6703 BD Wageningen, The Netherlands
  • Eddy J. Smid
    • Agrotechnological Research Institute (ATO-DLO), PO Box 17, 6700 AA Wageningen, The Netherlands
Original Paper

DOI: 10.1007/s002030000199

Cite this article as:
Ultee, A., Kets, E., Alberda, M. et al. Arch Microbiol (2000) 174: 233. doi:10.1007/s002030000199

Abstract.

Carvacrol, a natural antimicrobial compound present in the essential oil fraction of oregano and thyme, is bactericidal towards Bacillus cereus. A decrease of the sensitivity of B. cereus towards carvacrol was observed after growth in the presence of non-lethal carvacrol concentrations. A decrease of the melting temperature (Tm) of membranes from 20.5 °C to 12.6 °C was the immediate effect of the addition of carvacrol. Cells adapted to 0.4 mM carvacrol showed a lower membrane fluidity than non-adapted cells. Adaptation of 0.4 mM carvacrol increased the Tm from 20.5 °C to 28.3 °C. The addition of carvacrol to cell suspensions of adapted B. cereus cells decreased Tm again to 19.5 °C, approximately the same value as for the non-adapted cells in the absence of carvacrol. During adaptation, changes in the fatty acid composition were observed. The relative amount of iso-C13:0, C14:0 and iso-C15:0 increased and cis-C16:1 and C18:0 decreased. The head-group composition also changed, two additional phospholipids were formed and one phospholipid was lacking in the adapted cells. It could be concluded that B. cereus adapts to carvacrol when present at non-lethal concentrations in the growth medium by lowering its membrane fluidity by changing the fatty acid and head-group composition.

Bacillus cereus Carvacrol Adaptation Membranes Gel-to-liquid-crystalline transition temperature Fatty acid composition Head-group composition Membrane fluidity

Copyright information

© Springer-Verlag 2000