CHIBI, Asma2024-07-292024-07-292024https://dspace.univ-annaba.dz//handle/123456789/3604This work firstly focuses on the study of the fungal process associated with stored wheat grains (3 varieties treated and 5 untreated with a fungicide) and plants. Mycological analysis revealed a diverse fungal flora, including mycotoxic species. 80 strains were detected; including 53 identified belonging to 18 genera Fusarium, Alternaria, Aspergillus, Penicillium,... In this context, this document presents the results on the evaluation of the biological activities of certain plant resources from Eastern Numidia and their exploitation in the conservation of wheat Triticum durum Defs. 4 EOs and 8 botanical extracts from 8 cultivated plants from Algeria (Cupressus sempervirens, Salvia rosmarinus, Eucalyptus polybractea, Lantana camara, Morus alba, Rubus ulmifolius, Dittrichia viscosa et Thuja orientalis) in comparison with sodium bicarbonate and two fungicides. The chemical analysis of EOs by GC/MS/MS made it possible to identify 65 compounds for C. sempervirens and L. camara, as well as 45 compounds for S.rosmarinus and E. polybractea. The results of the antibacterial activity of these EOs against six pathogenic bacteria as Pseudomonas aeruginosa ATCC27853, Staphylococus aureus ATCC25923, cherichia coli ATCC25922, Salmonella sp., S. aureus, P. aeruginosa and one yeast Candida albicans presented great antimicrobial activities against most of them at minimum inhibitory concentration (MIC) values ranging from 0.91 to 8.7 mg/mL.Furthermore, the investigation of insecticidal activity against a model of stored wheat pest, Tribolium castaneum, by fumigation and repellent tests demonstrated the dependence of the effectiveness of these activities on the concentration and the exposure time. It should be noted that unlike the activity of plant extracts, fumigation of EOs gave better results since the highest concentration tested gave 100% insecticidal activity. The botanical extracts used appear to be a romising, effective, economical and ecological alternative for the biological treatment of fungi and insects, with remarkable antibacterial power.enThesis