title: Effect of Essential Oils on Germination and Growth of Some Pathogenic and Spoilage Spore-Forming Bacteria.
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.
authors.affiliation: 1 Department of Microbiology, Laboratory of Microbiology, University of Yaounde I , Yaounde, Cameroon .|2 Department of Biochemistry, Laboratory of Phytobiochemistry and Medicinal Plant Study, University of Yaounde I , Yaounde, Cameroon .
authors.forename: Stève Olugu
authors.initials: SO
authors.lastname: Voundi
authors.affiliation: 1 Department of Microbiology, Laboratory of Microbiology, University of Yaounde I , Yaounde, Cameroon .|2 Department of Biochemistry, Laboratory of Phytobiochemistry and Medicinal Plant Study, University of Yaounde I , Yaounde, Cameroon .
authors.forename: Maximilienne
authors.initials: M
authors.lastname: Nyegue
authors.affiliation: 3 Departments of Food and Chemical Engineering, Vasile Alecsandri University of Bacau , Bacau, Romania .
authors.forename: Iuliana
authors.initials: I
authors.lastname: Lazar
authors.affiliation: 4 Biology, Ecology, and Environment Protection, Vasile Alecsandri University of Bacau , Bacau, Romania .
authors.forename: Dumitra
authors.initials: D
authors.lastname: Raducanu
authors.affiliation: 2 Department of Biochemistry, Laboratory of Phytobiochemistry and Medicinal Plant Study, University of Yaounde I , Yaounde, Cameroon .
authors.forename: Florentine Foe
authors.initials: FF
authors.lastname: Ndoye
authors.affiliation: 5 Mechanical and Environmental Engineering, Vasile Alecsandri University of Bacau , Bacau, Romania .
authors.forename: Stamate
authors.initials: S
authors.lastname: Marius
authors.affiliation: 1 Department of Microbiology, Laboratory of Microbiology, University of Yaounde I , Yaounde, Cameroon .
authors.forename: François-Xavier
authors.initials: FX
authors.lastname: Etoa
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D001407:Bacillus / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D001409:Bacillus cereus / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D001410:Bacillus megaterium / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D001412:Bacillus subtilis / Q000187:drug effects / Q000254:growth & development / Q000502:physiology; D002163:Cameroon; D015169:Colony Count, Microbial; D057168:Distillation; D055808:Drug Discovery; D004357:Drug Synergism; D019669:Embryophyta / Q000737:chemistry; D020834:Ethnopharmacology; D005520:Food Preservatives / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D001411:Geobacillus stearothermophilus / Q000187:drug effects* / Q000254:growth & development / Q000502:physiology; D017879:Isothiocyanates / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D024301:Plant Bark / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry; D013171:Spores, Bacterial / Q000187:drug effects / Q000254:growth & development / Q000502:physiology
chemical_list: D000900:Anti-Bacterial Agents; D005520:Food Preservatives; D017879:Isothiocyanates; D009822:Oils, Volatile; C031403:benzyl isothiocyanate