---
title: "Philippine Researchers Test Lemongrass and Citronella Essential Oils as Antibiotic Alternatives in Tilapia Aquaculture"
summary: "A project led by the University of the Philippines Visayas and funded by DOST-PCAARRD has found that lemongrass and citronella essential oils show promise as natural, antibiotic-free feed additives for saline-tolerant tilapia, though researchers say further validation is needed before commercial application."
url: "https://feedsoft.ai/articles/philippine-researchers-test-lemongrass-and-citronella-essential-oils-as-antibiotic-alternatives-in-t-14f36838"
publisher: "The Feed Report"
section: "Aquafeed"
author: "The Feed Desk"
datePublished: "2026-10-04T16:27:39.617Z"
dateModified: "2026-10-04T16:27:39.617Z"
sources:
  - title: "Lemongrass and citronella essential oil-based feed additives explored as aquaculture alternatives to antibiotics"
    url: "http://pcaarrd.dost.gov.ph/index.php/quick-information-dispatch-qid-articles/lemongrass-and-citronella-essential-oil-based-feed-additives-explored-as-aquaculture-alternatives-to-antibiotics"
---

# Philippine Researchers Test Lemongrass and Citronella Essential Oils as Antibiotic Alternatives in Tilapia Aquaculture

*A project led by the University of the Philippines Visayas and funded by DOST-PCAARRD has found that lemongrass and citronella essential oils show promise as natural, antibiotic-free feed additives for saline-tolerant tilapia, though researchers say further validation is needed before commercial application.*

Researchers at the University of the Philippines Visayas (UPV) have tested locally sourced lemongrass and citronella essential oils as feed additives for saline-tolerant tilapia (*Oreochromis niloticus*), exploring their potential as natural alternatives to antibiotic growth promoters in aquaculture hatchery and nursery settings, according to a report published 30 September 2026 by the Philippine Council for Agriculture, Aquatic and Natural Resources Research and Development of the Department of Science and Technology (DOST-PCAARRD).

The project, titled "Development of Locally-Available Essential Oil as a Growth-Promoting and Antimicrobial Feed Additive for Saline-Tolerant Tilapia (*Oreochromis niloticus*)," was implemented by UPV and funded by DOST-PCAARRD. It was motivated by ongoing disease and mortality challenges in tilapia farming, with the source noting that "disease outbreaks and poor culture conditions continue to cause mortalities in tilapia farms" and that "the use of antibiotics to control these diseases can also have negative effects on the environment."

The project team screened approximately 15 essential oil products for antibacterial activity against pathogens commonly linked to fish diseases, including *Aeromonas*, *Vibrio*, and *Pseudomonas* species. Three oils demonstrated broad antibacterial activity: citronella (*Cymbopogon winterianus*), calamansi (*Citrofortunella macrocarpa*), and lemongrass (*Cymbopogon citratus*).

The team also investigated encapsulation of the selected oils — a process described in the source as "coating the ingredients into a protective shell." According to the report, calamansi essential oil showed reduced antibacterial activity after encapsulation, a result attributed to the volatility of its major component, D-limonene. By contrast, citronella oil, which is rich in Geraniol, "exhibited antibacterial activity in a wide range of bacterial species — broad spectrum," while lemongrass oil, which contains Citral, "showed an even stronger antibacterial activity."

The lemongrass and citronella essential oils were subsequently tested as feed additives during hatchery and nursery phases at UPV, applied both as a feed premix and as a coating directly on feed. The source reports that citronella essential oil supplementation "shows positive impact on improving the growth performance of the tilapia through the enhancement of metabolic efficiency and modulating the gut microbiota, without disrupting microbial diversity or host immune balance." Lemongrass essential oil was reported to show "potential as a natural and sustainable alternative to antibiotic growth promoters in aquaculture, capable of improving host performance and health through integrated effects on immunity, gut morphology, and micro biome dynamics."

Despite the encouraging results, the researchers cautioned that both oils "need to be further applied to larger sample sizes and subjected to functional analyses and validation, to better confirm the findings, refine application for commercial use, and confirm mechanisms of action and long-term effects." The project also noted that "excessive EO supplementation may exert inhibitory effects, emphasizing the importance of dose optimization."

## Sources

- [Lemongrass and citronella essential oil-based feed additives explored as aquaculture alternatives to antibiotics](http://pcaarrd.dost.gov.ph/index.php/quick-information-dispatch-qid-articles/lemongrass-and-citronella-essential-oil-based-feed-additives-explored-as-aquaculture-alternatives-to-antibiotics)

*Cite as: The Feed Report, "Philippine Researchers Test Lemongrass and Citronella Essential Oils as Antibiotic Alternatives in Tilapia Aquaculture", https://feedsoft.ai/articles/philippine-researchers-test-lemongrass-and-citronella-essential-oils-as-antibiotic-alternatives-in-t-14f36838 (as of 2026-10-04).*