Studi in Vitro Potensi Antibakteri Ekstrak Kasar Daun Ketapang (Terminalia Catappa) terhadap Bakteri Patogen Penyebab Vibriosis pada Budidaya Udang Vaname: In Vitro Antibacterial Activity of Crude Extracts from Ketapang Leaves (Terminalia catappa) Against Pathogenic Bacteria Causing Vibriosis in Vannamei Shrimp Farming - Rangkuti, Rizky Fadilla Agustin; Sanoesi, Ellana; Suprastyani, Heny; Meilinda, Novia Shely; Amanda, Bethrin (Faculty of Fisheries and Marine Science, Brawijaya University, Malang, Indonesia, 2025)
Vibriosis merupakan penyakit yang menginfeksi udang disebabkan oleh bakteri genus Vibrio. Vibrio vulnificus dan Vibrio alginolyticus merupakan spesies bakteri penyebab Vibriosis yang mampu menyebabkan kematian organisme hingga 80% dalam kurun waktu 24-72 jam. Upaya pengobatan menggunakan antibiotik dapat menyebabkan resistensi dalam jangka waktu lama. Alternatif yang dapat digunakan adalah pemanfaatan bahan alami, seperti daun ketapang (T. catappa) yang mengandung senyawa antibakteri, seperti tanin, saponin, fenolik, dan alkaloid. Penelitian ini bertujuan untuk menguji aktivitas antibakteri serta menentukan konsentrasi daya hambat ekstrak kasar daun ketapang terhadap bakteri V. vulnificus dan V. alginolyticus. Pengujian daya hambat ekstrak kasar daun ketapang terhadap bakteri V. vulnificus dan V. alginolyticus dilakukan melalui uji MIC dilanjutkan dengan difusi cakram. Konsentrasi ekstrak kasar daun ketapang yang digunakan pada uji MIC yaitu kontrol negatif (DMSO 10%), kontrol positif (Oxytetracycline 30 µg), A (62,5 ppm), B (125 ppm), C (250 ppm), D (500 ppm), dan E (1000 ppm) inkubasi 24 jam, sedangkan konsentrasi ekstrak kasar daun ketapang yang digunakan pada uji difusi cakram yaitu kontrol, A (500 ppm), B (725 ppm), dan C (1000 ppm), inkubasi 24 dan 48 jam. Parameter utama penelitian ini adalah nilai konsentrasi hambat minimal (MIC) dan diameter zona hambat. Penelitian menunjukkan bahwa ekstrak kasar daun ketapang berpengaruh signifikan terhadap bakteri Vibrio vulnificus dan V. alginolyticus dengan konsentrasi penghambatan minimal (MIC) sebesar 500 ppm. Ekstrak kasar daun ketapang konsentrasi 500 ppm menghasilkan diameter zona hambat terkecil pada bakteri V. alginolyticus sebesar 7,18 ± 0,15 mm dan 8,50 ± 0,50 mm terhadap bakteri Vibrio vulnificus. Diameter zona hambat tertinggi terdapat pada konsentrasi 1000 ppm. Vibriosis is a disease commonly infecting shrimp, caused by bacteria from the genus of Vibrio. Vibrio vulnificus and Vibrio alginolyticus are two of the Vibrio species responsible for Vibriosis, causing mortality rates of up to 80% within 24-72 hours. The treatment of bacterial diseases using antibiotics can lead to long-term resistance. An alternative approach is the use of natural materials, such as ketapang leaves (Terminalia catappa), which contain antibacterial phytocompounds such as tannins, saponins, phenolics, and alkaloids. This study aims to examine the antibacterial activity and determine the minimum inhibitory concentration (MIC) of crude ketapang leaf extract against Vibrio vulnificus and Vibrio alginolyticus. The inhibitory effect of ketapang leaf crude extract on Vibrio vulnificus and Vibrio alginolyticus was tested through Minimum Inhibitory Concentration (MIC) assays followed by disk diffusion tests. The concentrations of ketapang leaf crude extract used in the MIC test included a negative control (10% DMSO), a positive control (30 µg Oxytetracycline), and treatments A (62.5 ppm), B (125 ppm), C (250 ppm), D (500 ppm), and E (1000 ppm) with 24 hours of incubation. For the disk diffusion test, the concentrations included a control, A (500 ppm), B (725 ppm), and C (1000 ppm), with incubation periods of 24 and 48 hours. The main parameters in this study were the MIC value and the diameter of the inhibition zone. The study showed that ketapang leaf crude extract significantly affected Vibrio vulnificus and Vibrio alginolyticus, with a minimum inhibitory concentration (MIC) of 500 ppm. At a concentration of 500 ppm, the crude extract also produced the smallest inhibition zone diameter against V. alginolyticus (7.18 ± 0.15 mm) and V. vulnificus (8.50 ± 0.50 mm). The largest inhibition zone diameter was observed at a concentration of 1000 ppm.