Electronic Theses and Dissertation

Aeromonas hydrophila merupakan bakteri patogen Gram-negatif yang sering menyebabkan penyakit Motile Aeromonas Septicemia (MAS) pada ikan air tawar dan berpotensi menimbulkan kerugian besar dalam bidang perikanan. Penggunaan antibiotik sintetis secara berlebihan dapat menyebabkan resistensi antimikroba dan pencemaran lingkungan, sehingga diperlukan alternatif antibakteri alami yang ramah lingkungan. Penelitian ini bertujuan untuk mengidentifikasi kandungan senyawa bioaktif serta menguji aktivitas antibakteri ekstrak etanol daun mangrove Rhizophora mucronata terhadap bakteri Aeromonas hydrophila. Ekstraksi dilakukan menggunakan metode maserasi dengan pelarut etanol, kemudian dilakukan uji fitokimia untuk mendeteksi kandungan metabolit sekunder. Uji aktivitas antibakteri dilakukan menggunakan metode difusi cakram dengan variasi konsentrasi ekstrak sebesar 10%, 25%, 50%, 75%, dan 100%, serta menggunakan tetrasiklin sebagai kontrol positif dan etanol sebagai kontrol negatif. Hasil uji fitokimia menunjukkan bahwa ekstrak etanol daun R. mucronata mengandung senyawa alkaloid, flavonoid, triterpenoid, steroid, saponin, dan fenolik. Hasil uji antibakteri menunjukkan bahwa seluruh konsentrasi ekstrak mampu menghambat pertumbuhan A. hydrophila dengan diameter zona hambat berkisar antara 11,29–13,89 mm dan termasuk dalam kategori daya hambat kuat. Diameter zona hambat tertinggi diperoleh pada konsentrasi 100%. Berdasarkan hasil penelitian, dapat disimpulkan bahwa ekstrak etanol daun mangrove R. mucronata berpotensi sebagai sumber antibakteri alami terhadap Aeromonas hydrophila.

Kata kunci: Rhizophora mucronata, Antibakteri, Aeromonas hydrophila, Senyawa Bioaktif, Maserasi.

Aeromonas hydrophila is a Gram-negative pathogenic bacterium that commonly causes Motile Aeromonas Septicemia (MAS) in freshwater fish and leads to significant losses in aquaculture. Excessive use of synthetic antibiotics may result in antimicrobial resistance and environmental pollution, highlighting the need for environmentally friendly natural antibacterial alternatives. This study aimed to identify bioactive compounds and evaluate the antibacterial activity of ethanol extract from mangrove leaves Rhizophora mucronata against Aeromonas hydrophila. Extraction was performed using the maceration method with ethanol as the solvent, followed by phytochemical screening to detect secondary metabolites. Antibacterial activity was assessed using the disc diffusion method with extract concentrations of 10%, 25%, 50%, 75%, and 100%, while tetracycline and ethanol were used as positive and negative controls, respectively. Phytochemical analysis revealed the presence of alkaloids, flavonoids, triterpenoids, steroids, saponins, and phenolic compounds in the ethanol extract of R. mucronata leaves. The antibacterial assay demonstrated that all extract concentrations inhibited the growth of A. hydrophila, with inhibition zone diameters ranging from 11.29 to 13.89 mm, categorized as strong inhibitory activity. The highest inhibition zone was observed at the 100% extract concentration. These results indicate that ethanol extract of R. mucronata leaves has strong potential as a natural antibacterial agent against A. hydrophila. Keywords: Rhizophora mucronata, Antibacterial Activity, Aeromonas hydrophila, Bioactive Compounds, Maceration.