Effect of Fertilizer Treatment on the Antimicrobial Activity of the Leaves of Ocimum gratissimum L. and Gongronema latifolium Benth.

摘要

The effect of fertilizer treatment on the antimicrobial activities of the leaves of Ocimum gratissimum (L.) and Gongronema latifolium (Benth) was investigated. Cultivated O. gratissimum and G. latifolium were applied with NPK (15:15:15) fertilizer at100, 200, 300, 400 and 500 kg/ha treatment levels in planting buckets derived using the furrow slice method two months after seedling emergence. No fertilizer treatment served as control. Leaves were harvested one month after treatment. The ethanolic extracts of the harvested leaves were used to determine the sensitivity of the extracts on Klebsiella pneumoniae, Escherichia coli, Staphylococcus aurues, Pseudomonas aeruginosa, Salmonella typhi, Streptococcus faecalis, Candida albicans and Aspergillus niger. The result obtained showed that the antimicrobial activities of the leaves of O. gratissimum and G. latifolium was significantly (P < 0.05) increased by fertilizer treatment. The inhibition zone increased with increase in the level of fertilizer treatment. The ethanolic extracts of both plants whether treated or not had no antimicrobial effect on A. niger. This research revealed that fertilizer treatment might have increased the phytochemical content of the leaves of the plants which in turn enhanced their antimicrobial potential. These phytochemicals are known to exhibit physiological activities against bacteria and other microorganisms.