Antibacterial of Limonene Against Gram Negative and Positive Bacteria

Foodborne disease outbreaks are prevalent worldwide, affecting human health which requires using medical products to heal. However, most medical contain nano-silver antimicrobial agents can kill bacteria and fungi, however and harms human organs based on several articles. Alternatively, limonene is a natural extract from citrus fruits and can be used as an antibacterial agent to combat these diseases. Its bio-material properties make it safe for skin contact and environmentally friendly, making it a promising candidate for addressing foodborne illnesses. This study investigates the susceptibility of limonene to the Gram-negative bacteria, Escherichia coli, and the Gram-positive bacteria, Bacillus Subtilis, by applying the minimum inhibitory concentration (MIC) method and disc diffusion method. The result of exterior ring diameter of inhibition stated mean value and standard deviation of Bacillus Subtilis at 1.133 ± 0.3682 is higher than Escherichia coli at1.067 ± 0.2055 indicated limonene is effectiveness against Bacillus Subtilis. Though the comparison limonene and nanoparticle silver has stated limonene is preferable antibacterial resistance due to the limonene produced 10 % higher than nanoparticle in comparison on the initial diameter inhibition zone against Escherichia coli through disc assay. The MIC method was applied to Bacillus Subtilis by diluting limonene with LB broth consecutively in each falcon tube and measuring optical density (OD) before and after incubation. As a result, only one petri dish has lower colonies at an optical density of 0.809 decreased from 0.834 which indicates that the minimum concentration dosage was 1 % (v/v). Therefore, these results indicate that limonene is bacteriostatic against Bacillus Subtilis in MIC.