APLIKASI BAKTERIOFAG FREEZE-DRIED SEBAGAI AGEN PREVENTIF WHITE FECES DISEASE PADA UDANG VANAME (Litopenaeus vannamei) DALAM MENEKAN MORTALITAS

White Feces Disease is one of the diseases that attack shrimp ponds in Indonesia. The disease causes the growth of whiteleg shrimp to be inhibited until death occurs. Prevention efforts are the use of antibiotics that can cause pathogen resistance and reduce microbial activity. The latest alternative is using phages or bacteriophages to overcome the problem of pathogenic bacterial infections that cause WFD, the use of which is more profitable than antibiotics and herbs. However, as free virions, phages are sensitive to various environmental factors. Therefore, a method is needed that can increase the resistance of the right phage, namely the freeze drying method. The purpose of this study was to determine that phages can be preserved and can be a product that has the potential to overcome WFD but does not significantly affect shrimp growth. Whiteleg shrimp were obtained from BAPL Situbondo with a size of 6-8 grams as many as 500. This research method uses a Completely Randomized Design (CRD) design consisting of 5 treatments and 4 replications. The parameters observed were isolation, purification and propagation of bacteriophages, stability tests, in Vivo tests including Growth rate tests and FCR tests. Data analysis using the ANOVA test. The results of the study showed that bacteriophages can infect Vibrio alginolyticus bacteria, as shown by the appearance of plaque on double-layer agar, a decrease in the number of Vibrio alginolyticus bacterial colonies