Antibacterial activities of essential oils and their constituents against growth of Xanthomonas species

In a preliminary evaluation essential oils from Pimpinella anesum, Artemisia annua, Cymbopogon martini, Mentha piperita, Apium graveolens and pure constituents such as limonene, oc-terpineol, p-cymene, eugenol and linalool were investigated against growth of phytopathogenic bacteria Xanthomonas species. Essential oil from Apium graveolens and pure constituents, such as, eugenol and a-terpineol showed maximum inhibition of growth of Xanthomonas citri under in vitro i.e. 84, 86 and 84%, respectively. Besides these, Cymbopogon martini and p-cymene could also inhibited the growth of X. citri up to 81 and 53%, respectively. While in case of Xanthomonas campestris, Apium graveolens and eugenol showed 88 and 72% growth inhibition, respectively. The study suggested that the tested extracts, especially from A graveolens, and pure constituents-eugenol and a-terpineol, had potential to act as natural inhibitors for the growth of Xanthomonas species.