Work

Antibacterial Activity of Eucalyptus Essential Oils in Both Culture Media and Coated Materials

Year: 2025

Type: article

Abstract: Different factors, including microbial resistance, have led to food contamination and increased human intoxication risks. Therefore, finding new adequate methods to fight against bacterial development is of interest. This study investigates the efficiency of eucalyptus essential oils to inhibit the growth of Escherichia coli , Klebsiella pneumoniae , Listeria innocua , Salmonella typhimurium , Staphylococcus aureus, and Streptococcus pyogenes. Oils were extracted from eucalyptus leaves by hydrodistillation and chemically analyzed on a coupled gas chromatography–mass spectrometer. The antibacterial activity was assessed in both culture media and film models. Results indicated that eucalyptus oils were rich in different chemicals including α ‐pinene in oils from E. obliqua (89.3%), E. grandis (39.9%), and E. microcoris (29.6%); p‐cymene in E. camaldulensis (40.1%) and E. grandis (25.8%); and eucalyptol in E. viminalis (88.3%), E. crebra (84.6%), E. polyanthemus (80.7%), E. melliodora (78%), E. maiden (74.8%), and E. globulus (70.4%) oils. Terpinen‐4‐ol was found in E. anceps (5.7%) and E. camaldulensis (5.6%) while oils from E. anceps contained β ‐phellandrene (4.7%), cis‐ and trans‐piperitols (6.5%), (cis)‐p‐(2 menthen)‐1‐ol (8.3%), geraniol (19.9%), and piperitone (10.5%). In comparison with a known antibiotic, azithromycin, essential oils from E. grandis and E. anceps exhibited significant antimicrobial efficacy against the growth of all tested microorganisms. The antibacterial efficiency from these oils was found to be higher than other essential oils tested ( p < 0.05), with minimum inhibitory concentration and minimum bactericidal concentration ranging from 0.5 to 7 and 2.5 to 20 μ L/mL, respectively. Yet, at all concentrations tested (5–15 μ L/mL), hydroxy‐propyl cellulose (HPC) films containing these oils indicated significant inhibition efficacy of the growth of bacteria compared to HPC films ( p < 0.001). Further study on E. grandis and E. anceps oils is needed for their various valorization.

Source: International Journal of Microbiology

DOI: 10.1155/ijm/2756030

Authors: Théoneste Muhizi, Gervais Manizabayo, Colores Uwamariya, Jean Bosco Nkuranga, Daniel Umereweneza

Institution: College of Science and Technology - University of Rwanda

Language: English

Topic: Essential Oils and Antimicrobial Activity

Subfield: Food Science

Field: Agricultural and Biological Sciences

Domain: Life Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $1,000