Uji Aktivitas Antibakteri Kalsium Oksida (CaO) dari Cangkang Kapah Terhadap Bakteri Vibrio sp.
Abstrak Budidaya udang windu (Penaeus monodon) menghadapi ancaman serius akibat infeksi bakteri Vibrio sp., yang dapat menyebabkan vibriosis dan Acute Hepatopancreatic Necrosis Disease (AHPND) dengan tingkat mortalitas lebih dari 90%. Penggunaan antibiotik sintetis yang tidak terkontrol dapat memicu resistensi bakteri dan meninggalkan residu berbahaya pada produk perikanan, sehingga diperlukan alternatif antibakteri yang efektif dan ramah lingkungan. Penelitian ini bertujuan mengevaluasi efektivitas kalsium oksida (CaO) yang disintesis dari limbah cangkang kerang kapah (Meretrix sp.) sebagai agen antibakteri terhadap Vibrio sp. CaO diperoleh melalui kalsinasi tepung cangkang pada suhu 1000°C dan dikarakterisasi menggunakan spektroskopi FTIR. Pengujian aktivitas antibakteri dilakukan dengan metode difusi cakram menggunakan Rancangan Acak Lengkap (RAL) dengan lima perlakuan yaitu kontrol positif amoksisilin, kontrol negatif etanol, CaO 5%, 10%, dan 15%, masing-masing tiga ulangan. Hasil karakterisasi FTIR mengkonfirmasi terbentuknya CaO yang ditandai munculnya puncak vibrasi ikatan Ca–O pada bilangan gelombang 551,64 cm⁻¹ dan 397,34 cm⁻¹. Hasil pengujian menunjukkan bahwa seluruh konsentrasi CaO mampu menghambat pertumbuhan Vibrio sp., dengan diameter zona hambat tertinggi pada konsentrasi 15% sebesar rata-rata 5,67 mm.Uji One Way ANOVA menunjukkan perbedaan signifikan antar perlakuan (p = 0,006; p 0,05), mengindikasikan bahwa aktivitas antibakteri CaO bersifat semakin tinggi konsentrasi, semakin kuat efeknya. Mekanisme kerja antibakteri melalui, pembentukan Reactive Oxygen Species (ROS), denaturasi protein, dan kerusakan membran sel bakteri. Penelitian ini menyimpulkan bahwa CaO dari cangkang kerang kapah berpotensi dikembangkan sebagai agen antibakteri alami dan ramah lingkungan untuk mendukung budidaya udang yang berkelanjutan. Kata kunci: Akuakultur; Difusi cakram; Meretrix sp.; Vibrio sp.; Zona hambat. Abstract Tiger prawn (Penaeus monodon) aquaculture faces a serious threat from Vibrio sp. bacterial infections, which can cause vibriosis and Acute Hepatopancreatic Necrosis Disease (AHPND), with a mortality rate exceeding 90%. The uncontrolled use of synthetic antibiotics can trigger bacterial resistance and leave harmful residues in fishery products, necessitating the development of effective and environmentally friendly antibacterial alternatives. This study aims to evaluate the effectiveness of calcium oxide (CaO) synthesized from waste shells of the kapah clam (Meretrix sp.) as an antibacterial agent against Vibrio sp. CaO was obtained through calcination of shell powder at 1000°C and characterized using Fourier Transform Infrared (FTIR) spectroscopy. Antibacterial activity testing was conducted using the disc diffusion method with a Completely Randomized Design (CRD), comprising five treatments: a positive control of amoxicillin, a negative control of ethanol, and CaO at concentrations of 5%, 10%, and 15%, each replicated three times. FTIR characterization confirmed the formation of CaO, indicated by the appearance of Ca-O bond vibration peaks at wavenumbers of 551.64 cm¹ and 397.34 cm. The results show that all CaO concentrations were capable of inhibiting the growth of Vibrio sp., with the highest inhibition zone diameter recorded at the 15% concentration, yielding a mean of 5.67 mm. One-Way ANOVA revealed significant differences among treatments (p=0.006; p 0.05), indicating a concentration-dependent antibacterial activity, whereby higher concentrations produced stronger inhibitory effects. The antibacterial mechanism operates through the formation of Reactive Oxygen Species (ROS), protein denaturation, and bacterial cell membrane damage. This study concludes that CaO derived from kapah clam shells has potential for development as a natural and environmentally friendly antibacterial agent to support sustainable prawn aquaculture. Keywords: Aquaculture, Disc Diffusion, Meretrix sp., Vibeto sp., Inhibition Zone.