Effect of Essential Oils on Germination and Growth of Some Pathogenic and Spoilage Spore-Forming Bacteria

Foodborne Pathog Dis. 2015 Jun;12(6):551-9. doi: 10.1089/fpd.2014.1892. Epub 2015 Apr 17.

Abstract

The use of essential oils as a food preservative has increased due to their capacity to inhibit vegetative growth of some bacteria. However, only limited data are available on their effect on bacterial spores. The aim of the present study was to evaluate the effect of some essential oils on the growth and germination of three Bacillus species and Geobacillus stearothermophilus. Essential oils were chemically analyzed using gas chromatography and gas chromatography coupled to mass spectrometry. The minimal inhibitory and bactericidal concentrations of vegetative growth and spore germination were assessed using the macrodilution method. Germination inhibitory effect of treated spores with essential oils was evaluated on solid medium, while kinetic growth was followed using spectrophotometry in the presence of essential oils. Essential oil from Drypetes gossweileri mainly composed of benzyl isothiocyanate (86.7%) was the most potent, with minimal inhibitory concentrations ranging from 0.0048 to 0.0097 mg/mL on vegetative cells and 0.001 to 0.002 mg/mL on spore germination. Furthermore, essential oil from D. gossweileri reduced 50% of spore germination after treatment at 1.25 mg/mL, and its combination with other oils improved both bacteriostatic and bactericidal activities with additive or synergistic effects. Concerning the other essential oils, the minimal inhibitory concentration ranged from 5 to 0.63 mg/mL on vegetative growth and from 0.75 to 0.09 mg/mL on the germination of spores. Spectrophotometric evaluation showed an inhibitory effect of essential oils on both germination and outgrowth. From these results, it is concluded that some of the essential oils tested might be a valuable tool for bacteriological control in food industries. Therefore, further research regarding their use as food preservatives should be carried out.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / isolation & purification
  • Anti-Bacterial Agents / pharmacology*
  • Bacillus / drug effects*
  • Bacillus / growth & development
  • Bacillus / physiology
  • Bacillus cereus / drug effects
  • Bacillus cereus / growth & development
  • Bacillus cereus / physiology
  • Bacillus megaterium / drug effects
  • Bacillus megaterium / growth & development
  • Bacillus megaterium / physiology
  • Bacillus subtilis / drug effects
  • Bacillus subtilis / growth & development
  • Bacillus subtilis / physiology
  • Cameroon
  • Colony Count, Microbial
  • Distillation
  • Drug Discovery*
  • Drug Synergism
  • Embryophyta / chemistry
  • Ethnopharmacology
  • Food Preservatives / chemistry
  • Food Preservatives / isolation & purification
  • Food Preservatives / metabolism
  • Geobacillus stearothermophilus / drug effects*
  • Geobacillus stearothermophilus / growth & development
  • Geobacillus stearothermophilus / physiology
  • Isothiocyanates / analysis
  • Isothiocyanates / isolation & purification
  • Isothiocyanates / pharmacology
  • Microbial Sensitivity Tests
  • Oils, Volatile / chemistry
  • Oils, Volatile / isolation & purification
  • Oils, Volatile / pharmacology*
  • Plant Bark / chemistry
  • Plant Stems / chemistry
  • Spores, Bacterial / drug effects
  • Spores, Bacterial / growth & development
  • Spores, Bacterial / physiology

Substances

  • Anti-Bacterial Agents
  • Food Preservatives
  • Isothiocyanates
  • Oils, Volatile
  • benzyl isothiocyanate