Antimicrobial activity of two natural plants grown in Egyptian environment: Ipomoea carnea and Tamarix nilotica

Document Type : Research articles.

Authors

1 Horticultural Crops Research Department, Food Technology Research Institute, Agriculture Research Center, Giza, Egypt. Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Egypt.

2 Department of Agricultural Microbiology, Faculty of Agriculture, Fayoum University, Egypt.

3 Horticultural Crops Research Department, Food Technology Research Institute, Agriculture Research Center, Giza, Egypt.

Abstract

Plants are the largest biochemical and pharmaceutical stores ever known on our planet. Some medicinal plants have not found wider application and sometimes are referred as "forgotten plants". Antimicrobial activity of Ipomoea carnea and Tamarix nilotica were evaluated by disk diffusion method and broth microdilution method. Extraction was performed by ethanol 50%. Results showed antibacterial activity of Tamarix nilotica extract with inhibition zones; 15, 14 and 19 mm against Bacillus cereus, Listeria monocytogenes and Staphylococcus aureus, respectively. Ipomoea carnea extract revealed a good effect against Staph. aureus with 18 mm inhibition zone and MIC value against Staph. aureus was 8 mg/ml. Gram positive bacteria; B. cereus and L. monocytogenes showed MIC value at 16 mg/ml likewise E. coli was at 16 mg/ml. Pseudomonas aeruginosa and Salmonella typhimurium were inhibited at 64 and 32 mg/ml, respectively. Gram positive strains were also susceptible to Tamarix nilotica extract with MIC values from 8 to 32 mg/ml. Gram negative strains were more resistant as MIC value were at 64 and 128 mg/ml. Bactericidal activity (MLC) at 16 mg/ml for both extracts against Staph. aureus while P. aeruginosa showed MIC at 128 mg/ml with Tamarix nilotica extract. Fungal strains were more resistant to the tested plant extracts whereas Ipomoea carnea extract showed MIC value 16 mg/ml against Penicillium italicum while Aspergillus flavus and Rhizopus stolonifera not inhibited at the highest concentration 128 mg/ml the yeast strains: Saccharomyces cerevisiae and Candida albicans were inhibited at 64 mg/ml. Tamarix nilotica extract showed MIC values ranged from 64 to 128 mg/ml against all tested fungal strains. It is reasonable to assessing their applicability and benefits using modern scientific analysis methods.

Keywords