Synergistic bactericidal effect of Cymbopogon citratus (lemongrass) and Zingiber officinale (Ginger) on selected gram positive and gram negative bacteria

Date of Completion


Document Type

Capstone Project

Degree Name

Grade 12


Bactericidal, Synergistic Effect, Zone of inhibition, Bacteria, Cymbopogon, Ginger


Cymbopogon citratus (Lemongrass) and Zingeber officinale (Ginger) are used as common herbal medicines because of their potential antimicrobial activity against various microbial pathogens. This study assessed the individual and synergistic bactericidal effect of the two extract in low concentrations. The lemongrass leaves and ginger rhizomes were air dried for 3-5 days. Then the dried plant samples were powdered and macerated in absolute ethanol and subjected to a rotary evaporator to obtain its ethanolic crude extract. Kirby Bauer disc diffusion technique was adopted in testing the effectiveness of the extracts. It was tested alongside commercially accessible antibiotics, penicillin and amoxicillin, as the positive controlled groups. The results showed no zone of inhibition in the extracts with low concentrations compared to the antibiotics that yielded significant measurements. The findings showed that commercially available antibiotics were superior compared to the set concentrations of extracts of lemongrass and ginger. The use of high concentrations of extracts, as well as different type of gram-positive and gram-negative bacteria are recommended in future studies in order to further test the effectivity of the aforementioned plant samples.

First Advisor

Dennis Yu Perona

This document is currently not available here.