How to cite:
Dumlao, R., Balete, C. M., Martin, B., & Maines, M. S. (2026). In Vitro Antibacterial Activity of Calamansi Peels and Lemongrass Leaves Ethanol Extracts Against Escherichia coli. Research Journal of Science Innovation, Anthropology, Sustainable Agriculture, and Technology, 1(1), 50–59. https://doi.org/10.5281/zenodo.19910693
In-Text Citations
Narrative: Dumao et al. (2026)
Parenthetical:
(Dumlao et al., 2026)
Rowel S. Dumlao, Chelcy Mae G. Balete, Benajane D. Martin, Midge Seiman F. Maines
https://doi.org/10.5281/zenodo.19910693
Abstract
This study investigated the antibacterial potential of locally abundant plant materials in the Philippines, focusing on calamansi peel (Citrus microcarpa) agro-waste and lemongrass (Cymbopogon citratus) leaves as sustainable alternatives to synthetic antibiotics amid rising antimicrobial resistance. Despite known individual antimicrobial properties, limited evidence exists on their combined effects against Escherichia coli. The study aimed to determine and compare the antibacterial activity of individual and combined ethanol extracts and assess whether their interaction is synergistic or indifferent. A quantitative experimental design was employed using the Kirby–Bauer disk diffusion method. Ethanol extracts of calamansi peels, lemongrass leaves, and their combination were tested against a standardized E. coli culture with positive and negative controls, each in triplicate. Zones of inhibition (mm) were measured and analyzed using mean, standard deviation, one-way ANOVA, and Tukey’s HSD at a 0.05 significance. The results revealed mean zones of inhibition of 17.33 mm for calamansi ethanol extract, 18.00 mm for lemongrass ethanol extract, and 18.33 mm for the combined ethanol extract. Although the combined extract exhibited the highest mean inhibition, statistical analysis indicated no significant difference among the three plant treatments, suggesting an indifferent interaction rather than synergistic effect. The findings highlight the potential of calamansi peels and lemongrass leaves as natural antibacterial agents and support their application in eco-friendly disinfectant formulations. Future studies should determine minimum inhibitory concentrations and conduct phytochemical profiling to strengthen product development.
Keywords: Calamansi, lemongrass, antibacterial activity, Escherichia coli, indifferent interaction
Click dropdown to show references
References
Ali, S. (2024). Comparative efficacy of plant-derived extracts with insecticide against whitefly species. Scientific Reports. https://www.nature.com/articles/s41598-024-84958-0
Andaya, P. (2023). The effectiveness of using selected organic spice and pomelo peel extract as an insecticide. Ascendens Asia Journal of Multidisciplinary Research Abstracts, 5(2). https://ojs.aaresearchindex.com/index.php/AAJMRA/article/view/12512
Bass, C. (2022). The global status of insect resistance to synthetic insecticides. Pest Management Science, 78(2), 389–398. https://doi.org/10.1002/ps.6682
Benelli, G. (2021). Botanical insecticides: Current status and future prospects. Industrial Crops and Products, 175, 113892. https://doi.org/10.1016/j.indcrop.2021.113892
Damalas, C. A. (2020). Farmers’ exposure to pesticides: Toxicity types and ways of prevention. International Journal of Environmental Research and Public Health, 17(7), 2371. https://doi.org/10.3390/ijerph17072371
Dubey, N. (2021). Prospects of botanical pesticides: Field efficacy and challenges. Journal of Plant Diseases and Protection, 128, 421–437. https://doi.org/10.1007/s41348-020-00409-5
Duza, G. (2020). Efficacy of botanical plant extracts against fruit and shoot borer (Leucinodes orbonalis G.) of eggplant (Solanum melongena L.). https://doi.org/10.2139/ssrn.4970253
Giuliano, G. (2024). Insecticidal activity of Allium sativum essential oil-based nanoemulsion against Spodoptera littoralis. Insects, 15(7), 476. https://www.mdpi.com/2075-4450/15/7/476
Habib Siam, M. (2024). Biology and management of eggplant (Solanum melongena L.) shoot and fruit borer: A review. Journal of the Bangladesh Agricultural University, 22(3), 267–276. https://doi.org/10.3329/jbau.v22i3.76396
Hoesain, M. (2023). Investigating the plant metabolite potential as botanical insecticides against Spodoptera litura. Cogent Food & Agriculture. https://doi.org/10.1080/23311932.2023.2229580
Imfeld, G. (2022). Insecticide effects on the abundance of springtails and mites in field mesocosms at an agricultural site. Ecotoxicology. https://pubmed.ncbi.nlm.nih.gov/36319919/
Isman, M. B. (2020). Botanical insecticides in the twenty-first century—Fulfilling their promise? Annual Review of Entomology, 65, 233–249. https://doi.org/10.1146/annurev-ento-011019-025010
Nabutse, D. (2025). Efficacy of selected botanical extracts against Tuta absoluta on tomato. International Journal of Horticultural Science, 31(1), 31–36. https://ojs.lib.unideb.hu/IJHS/article/view/15025
Ngegba, P. (2022). Use of botanical pesticides in agriculture as an alternative to synthetic pesticides. Agriculture, 12(5), 600. https://www.mdpi.com/2077-0472/12/5/600
Oke, O. (2020). Insecticidal and biochemical activity of essential oil from Citrus sinensis peel. Pesticide Biochemistry and Physiology, 168, 104643. https://www.sciencedirect.com/science/article/pii/S0048357520301383
Owen, M. (2023). Reducing pesticide risk through adoption of integrated pest management strategies. Journal of Integrated Pest Management, 14(1), 32. https://doi.org/10.1093/jipm/pmad002
Pavela, R. (2021). Botanical insecticides and their impacts. Industrial Crops and Products, 171, 113892. https://doi.org/10.1016/j.indcrop.2021.113892
Popowski, J. (2024). Glandular trichome rupture in tomato plants as a defense mechanism against insects. arXiv. https://arxiv.org/abs/2412.14507
Regnault-Roger, C. (2022). Essential oils in insect control: Low-risk products in a high-stakes world. Annual Review of Entomology, 57, 405–424. https://doi.org/10.1146/annurev-ento-120710-100554
Sánchez-Bayo, F. (2021). Worldwide decline of the entomofauna: A review of its drivers. Biological Conservation, 257, 109099. https://doi.org/10.1016/j.biocon.2021.109099
Seni, A. (2024). Pesticidal plant extract effect against major lepidopteran insect pests. Frontiers in Insect Science, 4, 1500542. https://www.frontiersin.org/articles/10.3389/finsc.2024.1500542/full
Sitorus, B. (2020). Insecticidal activity of garlic (Allium sativum) extract against insect pests. IOP Conference Series: Earth and Environmental Science, 454(1), 012154. https://doi.org/10.1088/1755-1315/454/1/012154
Sparks, T. (2020). IRAC: Mode of action classification and insecticide resistance management. Pesticide Biochemistry and Physiology, 167, 104587. https://doi.org/10.1016/j.pestbp.2020.104587
Subba, B. (2023). Plant-based organic insecticides. https://www.researchgate.net/publication/373396771
Visakh, N. (2022). Chemical characterization and insecticidal activities of essential oils from citrus peel waste. Food and Bioproducts Processing, 137, 102163. https://www.sciencedirect.com/science/article/pii/S221242922200623X
Vol1-Num1-April2026-Art5-Dumlao.pdf