Chitosan of Shrimp Shell as a Natural Antibiotic Candidate for Bacteria Vibrio harveyi and Vibrio alginolyticus Causes Vibriosis in Tiger Shrimp (Penaeus monodon)

This research was conducted with the aim to determine the potential of chitosan derived from shrimp shells as a candidate for natural antibiotics in Vibrio harveyi and Vibrio alginolyticus. Shrimp shells are extracted into chitin through the process of deproteination, demineralization and depigmentation, then the chitin obtained is transformed into chitosan through a deacetylation process. The chitosan produced was then measured in the form of water content, ash content, and the degree of deacetylation and then compared with the chitosan quality standard issued by the protan laboratory. The chitosan produced in this study fulfilled the chitosan quality standard that is the water content of 10.77%, ash content of 1.0839%, and the degree of deacetylation of 70.04%. Furthermore, the chitosan was applied in the inhibitory test of Vibrio harveyi and Vibrio alginolyticus using agar diffusion method with chitosan concentration of 1.00%, 0.75%, 0.50%, 0.25% and control acetat acid 2%. It was concluded that shrimp shells chitosan has a minimum inhibitory concentration on Vibrio harveyi and Vibrio alginolyticus bacteria at a concentration level of 0.25% each of 1.2000 mm and 2.8000 mm