Moses K. Tokan Pengarang Mbing Maria Imakulata Pengarang Gufran Darma Dirawan Pengarang

The purpose of this study was to determine the antibacterial potency of Callyspongia and utilization possibility as a companion in the biological control of ice-ice disease. This study is a factorial experiment consists of 3 factors, namely the kind of bacterial isolates from seaweed suffering of ice-ice disease, kind of solvent and the kind of Callyspongia. Each factor consists of three levels and replicated three times. Callyspongia antibacterial potency testing performed by agar diffusion method. Data in form the inhibition zone diameter. Data were analyzed by multiple ANOVA through SPSS. The results showed that the kind of solvent, kind of bacterial isolates and the kind of Callyspongia, either individually or jointly showed significantly different effects on inhibition zone diameter. Antibacterial of ethanol extract showed the most potent inhibitory effects compared with the methanol extract and diethyl ether extract. While the influence of the type Callyspongia, Callyspongia biru showed strongest inhibition compared with Callyspongia subarmigera and Callyspongia monilata. The results also showed that the three isolates were categorized as susceptible to antibacterial use of Callyspongia antibacterial. Based on these results, Callyspongia can be used as a companion on seaweed farming as a biological control agent of ice-ice disease.