Dmytrik Emmanuel C. Estilo, Nino P. Natividad, Mark Francis T. Rivera (February 2002)
Philippine Science High School Western Visayas Campus – Department of Science and Technology (DOST-PSHS WVC), Brgy. Bito-on, Jaro, Iloilo City 5000, Philippines
ABSTRACT
Using the Static Group Comparison Design, this study aimed to evaluate the antibacterial effect of coconut (Cocos nucifera) oil upon the gram-positive Staphylococcus aureus and Bacillus subtilis, and gram-negative Escherichia coli and Pseudomonas aeruginosa, and compare it with that of commercial antibiotics. It was hypothesized that there exists no significant difference in the zones of inhibition in the growth of these microorganisms when treated with the coconut oil and commercial antibiotics. The test bacteria were cultivated in the Petri plates and treated with coconut oil and commercial antibiotics previously absorbed by Whatman paper discs. The zones of inhibition around each Whatman disc were then observed. Results were subjected to different statistical data analyses, using the mean and standard deviation, as descriptive statistical tools, and the One-Way Analysis of Variance, set at 0.05 alpha level of significance and the Scheffe test, as inferential statistical tools.
Results showed that coconut oil had the greatest zone of inhibition on Bacillus subtilis with the mean as compared to Tetracycline, with a mean zone of inhibition of 6.8333 mm. It had the least zone of inhibition of 0.6667 mm, as compared to Erythromycin, with a mean zone of inhibition of 10.333 mm. As with Escherichia coli, coconut oil showed little antibacterial potential, with a mean zone of inhibition of 0.6333 mm, as compared to Piperacillin tazobactan, with a mean zone of inhibition of 8.600 mm. As with treating Pseudomonas aeruginosa, coconut oil still showed little antibacterial potential, with a mean zone of inhibition of 1.000 mm, against Azlocillin, with a mean zone of inhibition of 9.8333 mm.