Preliminary study on the effect of anaerobically digested cow dung slurry on the antimicrobial activity of three medicinal plants

Abstract

The study investigated the effect of anaerobically digested cow dung using polyethylene tube digester on the antimicrobial property of Aloe barbadensis, (Aloe vera) Allium sativum (Garlic) and Zingiber officinale (Ginger). The methanol extracts of the three medicinal plants grown on soil augmented with anaerobically digested cow dung slurry exhibited marked antimicrobial activities on Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Asperigillus niger and Trichophyton mentogrophyte isolated from clinical specimens. All the three medicinal plants grown on digested cow dung slurry exhibited greater mean zones of inhibition on all the pathogens than that grown on soil augmented with undigested cow dung and soil not augmented at all. A. sativum (Garlic) raised on digested cow dung slurry exhibited the highest mean zones of inhibitions with spore germination of the fungi totally inhibited when compared with the two other medicinal plants. The results in this study have shown that anaerobically digested cow dung slurry does not only yield pathogen free manure, increased fertilizer and biogas but can improve the antimicrobial activity of medicinal plants.