Study of the chemical composition of the essential oil derived from Thymus lancéolatus desf, an endemic aromatic plant native from Algeria and evaluation of its efficacy against Paenibacillus larvae and Ascosphaera Apis, two diseases affecting the ho

The essential oil and hydrolate of Thymus lancéolatus desf, an endemic aromatic plant native to the mountains of northwestern Algeria, were tested in vitro for their antimicrobial activity against the bacteria Paenibacillus larvae, the causative agent of American foulbrood, and the fungi Ascosphaera apis, the responsible agent of chalkbrood disease in honeybees, Apis mellifera. The oil was extracted from various aerial parts of the plant using steam distillation. It shows high efficacy against both diseases, while its hydrolat demonstrates high efficacy against A.apis alone. The lethal doses (LD100) of the fungi were estimated at 0.034% and 25.30% for the essential oil and the hydrolat, respectively. The estimated concentration of the DL100 bacteria was 17.37 ul/Disc of EO. The hydrolate had no effect on P. larvae. This exceptional double efficacy of T.lancéolatus desf EO has been attributed to its particular active compound, Durenol, which constitutes 34.8% of the oil and the high quantities of its precursors (γ-Terpinene (16.71%) and Sylvestrene (15.17%) contribute to its effectiveness. Also, the abcence of acetate compound further enhances its efficacy. EO of Thyme was proven to be the most effective essential oil in vitro against P. larvae and A. apis, making it an excellent natural alternative to antibiotics.