Antibacterial Effectiveness of Purple Yam (Dioscorea alata L) Sap Extract in Inhibiting the Growth of Staphylococcus aureus & Escherichia coli

Purple yam sap extracts have secondary metabolite components which can be utilized as an antibacterial property. Secondary metabolite compounds found from the result of the preliminary study include saponins, tannins, flavonoids, phenols, alkaloids, and triterpenoids. The aim of this study was to analyze the antibacterial activity of sap extracts towards the growth of Staphylococcus aureus and Escherichia coli bacteria. The maceration method of 96% ethanol as a solvent was used to obtain purple yam sap extracts with a 48-hour maceration time. The effectiveness of bacterial inhibition zones based on the minimum inhibitory concentration (MIC) was carried out by testing eight concentrations of 0.01%, 0.02%, 0.04%, 0.06%, 0.08%, 0.15%, 0.20%, and 0.25% with tetracycline as a positive control and dimethyl sulfoxide (DMSO) as a negative control. The results showed that the minimum inhibition of purple yam sap extracts with the 0.01% concentration inhibited the growth of gram-positive Staphylococcus aureus bacteria with a medium category of inhibition zone of 8.62 mm. On the other hand, gram-negative Escherichia coli bacteria form a minimum inhibition zone of 9.30 mm. The maximum extract concentration in inhibiting the growth of Staphylococcus aureus and Escherichia coli bacteria was 0.25% (21.77 mm,13.35 mm), which was categorized as the strongest inhibition zone for bacterial growth. Accordingly, purple yam sap extracts macerated with 96% ethanol during the 48hour period with 0.01% extract concentration were effective in inhibiting the growth of gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli).