Chemical composition and antimicrobial activity of essential oils of two wild olive subspecies Olea europaea L.var. sylvestris and the endemic olive Olea europaea subsp. lapperinie from Algeria

Abstract

Two wild olive subspecies are fixed in this research: Olea europaea L.var. sylvestris and Olea europaea subsp. laperrinei despite its ecological value, the chemical composition of subsp. laperrinei oil remains unknown. The samples were harvested from the different geographical area. Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-flame-ionization detection (GC-FID) analysis of Olea europaea L. var. sylvestris allowed the identification of 29 compounds oil with Nonanal (11.82%), theaspiranea A (9.81%), 3-hexen-1-ol,benzoate(9.31%) as a major constituents, while in the subspecies of the Saharan region 31 compounds were separated, where α-pinene (16%), β-Ocimene (12.82%), dl-Limonene (8.20%) were the main components. The results of the disc diffusion method showed that the two volatile oils have efficient antibacterial activity but, subsp. laperrinei essential oil has a higher range of inhibition, in which P. aeruginosa and B. subtilis showed an extreme sensitivity, while the K. pneumoniae bacterium shows a great resistance to the two essential oils.