ArticlePDF Available

Antimicrobial Activity of the Extract of Garlic and Onions


Abstract and Figures

This study investigated the pathogenicity of two fungi (A. niger and P .digitatum) and two bacteria (S. aureus and E. carotovora) on onion bulbs. The inoculated areas of the onion bulbs showed changes in their colour and the tissues macerated then an offensive smell developed. The three onion bulbs responded similarly. The nonautoclaved red onion extracts reduced radial growth of both fungi more than the autoclaved onesThe results on the radial growth indicated that the onion extracts were highly effective at the higher concentration (0.01, 0.1 and 1.0) compared to the lower concentration (0.001) and the control (0.00). Garlic extract at the higher concentration completely inhibited radial growth of both fungi.The yellow onion extract caused a reduction of mycelial dry weight of A. niger to about 60.46, 31.09, 23.04 and 5.95% at the concentrations 1.0, 0.1, 0.01 and 0.001, respectively. The white onion extract gave a reduction of about 38.77, 34.55, 20.73 and 4.41% at the Abdel-Rahim A. M., Abdel-Malik O. A. Idris & Sulieman A. E. 52 concentrations 1.0, 0.1, 0.01 and 0.001, respectively. The red onion extract caused a reduction of about 23.22, 16.51, 14.98 and 0.38% at the concentration 1.0, 0.1, 0.01 and 0.00.1, respectively. Garlic extract at the higher concentration (1.0) reduced 89.06% of mycelial dry weight of A. niger and 38.58, 2.88 and 2.11% at the concentrations 0.1, 0.01 and 0.001, respectively. While, onion extracts promote mycelial growth of the fungus P. digitatum garlic extract at the higher concentration reduced 93.29% of mycelial dry weight of that fungus and 25.93, 2.78 and 0.47% at the other concentrations (0.1, 0.01 and 0.001, respectively). The three onion extracts showed no effect on the spore germination of A. niger, while, 2.0% of the spores of P. digitatum were germinated at the higher concentration of the yellow onion extracts. Garlic extracts completely inhibited spore germination of both fungi at the higher concentration (1.0). The three onion extracts as well as the lower concentrations (0.1, 0.01 and 0.001) of the garlic extract have no effect on both bacteria. Although, the inhibition zone of S. aureus at the lower concentration (0.1) of the garlic extract was 0.5 cm, the higher concentration (1.0) of it completely inhibited bacteria.
Content may be subject to copyright.
A preview of the PDF is not available
Full-text available
The present study aimed at reviewing Sudanese medicinal plants screened for antifungal activity. A total of 85 plant species belonging to 48 families (42 dicotyledonous and 6 monocotyledonous) were reported to have antifungal activity against some fungal species. The family Fabaceae was reported to be the most screened family, while Acacia nilotica from the same family and subfamily Mimosoideae was reported to be the most screened species. On the other hand, a total of 20 fungal species belonging to 10 genera and 6 families were reported to be used in studies for antifungal activities from Sudanese plants, with the two genera Aspergillus and Candida being the most tested genera. Four methods for testing antifungal activities of Sudanese plants were used, with the cup-plate diffusion method being the most applied method (75.18%). It is hoped that this review will define the current situation of research for antifungal activities of Sudanese plants.
This study was carried out to determine the inhibitory effect of garlic juice against Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Salmonella typhimurium, Shigella flexneri. Staphylococcus aureus, Streptococcus mutans, Virio. parahaemolyticus which are food pathogenic bacteria and Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus plantarum, Lactococcus. lactis, Leuconostoc mesenteroides which are lactic acid bacteria. An aqueous extract of garlic was bacteriocidal against Gram-positive and Gram-negative bacteria in all concentrations (0.1∼2.5(w/v)%) tested in this experiment. Especially 0.5(w/v)% garlic juice inactivated completely E. coli, S. typhimurium, S. flexineri, V. parahaemolyticus and 1.0(w/v)% garlic juice perfectly reduced P. aeruginosa, S. mutans. Generally, the experiment result indicate that garlic juice restrains the growth of the pathogenic bacteria better than the lactic acid bacteria. Therefore, garlic has potential for the preservation of processed foods.
Prosopis juliflora-Blätter werden im Boden viel schwerer abgebaut als jene von Lupinus albus. Wasserextrakte aus Prosopis-Blättern hemmten im Gegensatz zu denen aus Lupinus-Blättern das Wachstum bestimmter Stammkulturen von Bakterien und Pilze, einschließlich Candida albicans. Diese Hemmung erwies sich als bakterizid gegen Staphylococcus aureus und als bakteriostatisch gegenüber Gram negativen Bakterien. Die Extrakte von Prosopis, nicht die von Lupinus, reduzierten auf Nährmedien die Keimzahlen von Bodenbakterien und Pilzen, sowie von cellulolytischen und symbiontisch fixierenden Bakterien. Diese Ergebnisse wurden im Zusammenhang mit der Beobachtung, daß Prosopis-Blätter enthaltende Böden für die Landwirtschaft wenig geeignet sind, diskutiert.
There is a renewed interest in the antimicrobial properties of spices. In vitro activities of several ground spices, their water and alcohol extracts, and their essential oils have been demonstrated in culture media. Studies in the last decade confirm growth inhibition of gram positive and gram negative food borne bacteria, yeast and mold by garlic, onion, cinnamon, cloves, thyme, sage and other spices. Effects in foods are limited to observations in pickles, bread, rice, and meat products. In general, higher spice levels are required to effect inhibition in foods than in culture media. Fat, protein, and water contents in foods affect microbial resistance as does salt content. Very few studies report on the effect of spices on spores, and on microbial inhibition in conjunction with preservatives and food processes. Of the recognized antimicrobial components in spices, the majority are phenol compounds with a molecular weight of 150 to 160 containing a hydroxyl group. Eugenol, carvacrol and thymol have been identified as the major antimicrobial compounds in cloves, cinnamon, sage and oregano.