IMBIV   05474
INSTITUTO MULTIDISCIPLINARIO DE BIOLOGIA VEGETAL
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
In vitro control of the phytopathogenic bacterium Streptomyces scabiei by lemon and orange essential oils
Autor/es:
VAZQUEZ, C.; LUCINI, E.I.; PRIETO, M.C.; MERLO C.; GROSSO, N.R.; ASENSIO, C.M.; ARCHILLA M.
Lugar:
Santiago de Chile
Reunión:
Congreso; ALAM 2018; 2018
Institución organizadora:
Asociación Latinoamericana de Microbiología
Resumen:
The genus Streptomyces (Order Actinomycetales) play an important role in soil nutrient cycling and produce biologically active secundary metabolites. Though, some Streptomyces species are important plant pathogens. S. scabiei has beenwidely described as the causal agent responsible for potato common scab (PCS), a worldwide disease that causes large economic losses. An alternative control strategy based on essential oils (EOs) could be appropriate. EOs are aromaticoily liquids obtained from aromatic plants. It is known that EOs of lemon and orange show antimicrobial activity against Gram-positive bacteria. The aim of this research was to determine the antibacterial effect of lemon (Citrus limon L. Burm.) and orange (Citrus sinensis L. Osbeck) EOs against S. scabies. Orange and lemon EOs were purchased in local market and were analyzed by gas chromatography coupled with mass spectrometry. Two bacterial strains of S. scabies were tested: M1, which was obtained by isolation from infected tubers harvested in Córdoba (Argentina), and M2, obtained from the Universidad de la República, Uruguay. Broad microdilution assay with resazurin (redox indicator)was carried out to determine de minimum inhibitory concentration (MIC). Additionaly the minimum bactericidal concentration (MBC) was determined. Lemon EO result mainly composed by limonene (48.38%), α-Citral (18.85%) and β-citral (16.29%), follow by traces of β-linalool (1.69%). Orange EO presented Limonene (96.74%), followed by traces of myrcene (1.78%), 1R-α-pinene (0.66%) and sabinene (0.40%). Lemon EO was more effective against S. scabiei, showing the lowest MIC and MBC for both strains (MIC on M1 and M2 =0.1575 g/L; MBC on M1 =0.1575 g/L and M2 =0.1772 g/L). The antibacterial effectiveness of lemon EO could be attributed to the high concentration of α-citral and β-citral, and the presence of β-linalool, previously reported for their antimicrobial effects. The presence of limonene could explain, in part, the strong antibacterial activity of lemon EO, and also could be responsible for orange EO antibacterial effectiveness (MIC on M1 =0.3513 g/L, M2 =0.3864 g/L; MBC on M1 =0.4215 g/L and M2 =1.2290 g/L). The results indicate that lemon and orange EOs are a promising alternative in PCS control.