The Effectiveness of the Candle Bush (Cassia alata L.) Leaf Extract in Preventing the Growth of Disease-Causing Gram-Negative Bacteria in Aquaculture

Et Al., Maryani

doi:10.21608/ejabf.2025.446708

The Effectiveness of the Candle Bush (Cassia alata L.) Leaf Extract in Preventing the Growth of Disease-Causing Gram-Negative Bacteria in Aquaculture

Author

Maryani et al.

10.21608/ejabf.2025.446708

Abstract

This study aimed to evaluate the antibacterial potential of candle bush (Cassia alata L.) leaf extract against Aeromonas hydrophila, Enterobacter aerogenes, and Edwardsiella tarda in vitro, and determine which species was most effectively inhibited. The experiment followed a split-plot design, with main plots consisting of bacterial species: A. hydrophila (A1), E. aerogenes (A2), and E. tarda (A3), and subplots comprising treatments of distilled water (K1) as the negative control, ethanol (K2) as the solvent control, and tetracycline (K3) as the positive control. The tested treatments included 50% (P1) and 100% (P2) concentrations of C. alata leaf extract, each with three replications. The results indicated that C. alata leaf extract was effective in inhibiting the growth of A. hydrophila and E. tarda. For A. hydrophila, the mean inhibition zone diameters were 9mm at 100% concentration and 7.7 mm at 50%, both categorized as moderate inhibition. For E. tarda, the inhibition zones measured 11mm at 100% (strong inhibition) and 7.3mm at 50% (moderate inhibition). In contrast, the extract did not inhibit the growth of E. aerogenes at either concentration. Among the tested bacteria, Edwardsiella tarda was the most effectively inhibited by C. alata leaf extract.

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