Antibacterial and Phytochemical Properties of Clove Extracts on Vegetable Spoilage Bacteria

The present study was carried out to analyze the antibacterial and phytochemical properties of clove extracts on vegetable spoilage bacteria. The study seeks to determine its potential use as bio-preservative. The bacteria used for this study were isolated from infected leaves of bitter leaf, pumpkin and cocoyam using spread plate technique. Phytochemical analysis was carried out with aqueous and methanol extracts. Bacterial isolates from the leaves included Bacillus spp., Micrococcus spp., Staphylococcus spp. and Actinomyces spp. The pumpkin leaf had the highest average number of bacterial colonies of 2.5 x 102 while cocoyam leaf had the least with 7.0 x 101.Actinomycetes sp2 had the highest zone of inhibition of 22.0 mm while Staphylococcus sp2 had the least zone of inhibition of 13.00 mm all at 500mg/ml. For aqueous extracts, Bacillus sp.3, Staphylococcus sp.1 had the highest zone of inhibition of 16.00 mm respectively while the least zones were observed in Staphylococcus sp.2 and Bacillus sp.3 at concentration of 250 mg/ml and 125 mg/ml respectively. Bacillus sp.1, Bacillus sp.2, Micrococcus sp. and Actinomyces sp.1 has Minimum Inhibition Concentration (MIC) of 125 mg/ml while Staphylococcus sp.1 and Staphylococcus sp.2 has 250mg/ml respectively for methanol extract. For aqueous extract, Bacillus sp.2, Micrococcus sp. and Actinomyces sp.1 has MIC of 250mg/ml, respectively and Staphylococcus sp.1 and Staphylococcus sp.2 has MIC of 500 mg/ml. The Minimum Bactericidal Concentration (MBC) for the methanol extracts was 125 mg/ml for Actinomyces sp.1 while Bacillus sp.2, Bacillus sp.3, Micrococcus sp. and Actinomyces sp.2 were 250 mg/ml respectively while Bacillus sp1, Bacillus sp2, Micrococcus sp., Staphylococcus sp.2 and Actinomyces sp.1 all has MBC of 500mg/ml, respectively on the aqueous extracts. The phytochemical analysis of the aqueous and methanol extracts of clove shows that saponins, tannins, amino acids, proteins, reducing sugar, glycosides, alkaloids, anthraquinone and phenols are present though in varying amounts. This study therefore recommends clove extract as an alternative source for bio-preservation in food and allied products.