Ournal of Pplied Cience and Nvironmental Anagement

The aim of this research is to comparatively study the phytochemical and antimicrobial properties of Bryophyllum pinnatum and Citrus aurantifolia leaf extracts and their synergy. Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa, Aspergillus niger, Mucor mucedo, Penicillium notatum and Candida albicans, were used as test organisms and the antimicrobial activity of the extracts was determined by the agar-well diffusion method. Synergistic antibacterial activity ranged from 0.0 ± 0.0 to 2.4 ± 0.6, 11.3 ± 0.9 to 23.5 ± 1.1, 16.7 ± 0.3 to 27.3 ± 0.6 and 8.7 ± 0.9 to 22.7 ± 0.9, for aqueous, ethanol, methanol and acetone extracts respectively. Extracts of C. aurantifolia were more effective against the test organisms than B. pinnatum extracts, except the aqueous extract. Synergistic antifungal activity of the aqueous extract was 0.0 ± 0.0 mm for all the test fungi, the synergistic antifungal activity ranged from 8.7 ± 0.6 mm to 14.0 ± 0.9 mm, 10.0 ± 0.9 mm to 21.7 ± 0.6 mm and 0.0 ± 0.0 mm to 20.0 ± 0.6 mm for the ethanol, methanol and acetone extract respectively. Larger zones of inhibition were observed in the methanol extract of the synergy than the other extracting solvents. The synergy gave higher zones of inhibition neither B. pinnatum extract nor C. aurantifolia extract could give. It was also observed that the extracts compared well with the standard antimicrobial agents used as positive control. The phytochemical analysis of the extract revealed the presence of phytochemical constituents which conferred antimicrobial property on the plants. From the foregoing, the methanol extract of the synergy is considered the most effective in the treatment of infections caused by the test organisms. © JASEM http://dx.doi.org/10.4314/jasem.v19i4.7