Nigella sativa. Known by the common name "black cumin" is a medicinal plant from the Ranunculaceae family. Widely used in traditional medicine and as a food condiment in the Arab world. Basing on the seeds of this plant. The Nigella Sativa extract prevented bacterial growth; yet their efficiency remains different. The effect of Nigella sativa extract, on Streptococcus faecalis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa by the method of aromatogramme, shows that these bacteria are inhibited. The extract of Nigella generated a zone of inhibition of 30, 25, 20, and 10mm respectively, Streptococcus faecalis, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli. Evaluation of antioxidant power, which was conducted using the method of trapping the free radical DPPH (1,1-diphenyl-2-picrylhydrazyl), said the methanol extract showed an antioxidant activity (IC50 = 12 256 mg / ml), higher than that recorded in the ascorbic acid (IC50 = 0.097 mg / ml).

Salvadora Persica is a plant known for its medicinal properties whose variety of pharmacological activities have been reported by many studies. Volatile extracts of Salvadora persica are obtained either by hydrodistilation or by using a Soxhlet apparatus from crushed roots by using hexane as solvent. The obtained result by hexane extraction 2.5% has given better results than the one got by steam distillation 0.05%. Thus, the extracts obtained have been analyzed by coupling (GC-MS). The following products are among the many products identified: The Eugenol, the Asarone the Borneol the Carvacrol, vanillin, the Cuminal, Camphor, Acetamide the n-benzyl, the benzyl Isocianate and the oily acids Oleic and palmitic that represents the majority of the products extracted.
The essential oil of action Persica - on Streptococcus faecalis, Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa by the method aromatogram- shows that these bacteria are inhibited. Therefore, essential oil Miswak generated a zone of inhibition of 40, 25 and 15mm respectively on Streptococcus faecalis, Escherichia coli and Staphylococcus aureus. Meanwhile, it did not influence Pseudomonas aeruginosa.
The antimicrobial activity of the essential oils has been evaluated by determining the minimum inhibitory concentration (MIC). Comparing the antibacterial effect with antibiotics, it was observed that the Miswak has a noticeable antibacterial power. It may, then, be an excellent oral hygiene agent.

In this study, the behavior of Xanthomonas fragariae, angular leaf spot of strawberry agent, was followed in the AB medium, enriched with nitrogen, phosphorus or with potassium, and in the soil of the Mamora forest with 14% to 28% of humidity in function of these fertilizer elements. The obtained results have shown that Na2HPO4 and NH4Cl, used, 0.01 and 0.05 mol/L, respectively as a phosphorus and nitrogen source, have a significant effect on the survival of Xanthomonas fragariae. By contrast, KCl, used as a source of Potassium, has no significant effect on the number of culturable cells.
The three sources used NPK, 14% and 28% showed a great influence on the number of culturable cells of Xanthomonas fragariae, either increasing or decreasing. Potassium, at 28 to 14% of humidity, inhibited the rate growth of Xanthomonas, while the phosphorus and nitrogen stimulated its growth, greater than 28% of humidity than 14%. Similarly the bacterial growth was not affected during the incorporation of NPK at different concentrations in the soil of Mamora.