AKTIVITAS KITINASE, LESITINASE, DAN HEMOLISIN ISOLAT DARI BAKTERI IKAN NILA (Oreochromis niloticus Lin.) YANG DIKULTUR DALAM KERAMBA JARING APUNG WADUK JATILUHUR, PURWAKARTA

Aeromonas hydrophila Lin. is one of opportunistic aquatic pathogen bacteria where its pathogenic behavior is influenced by chitinase, lechitinase, and toxin haemolycine, and causes high mortality in nile tilapia culture. The purpose of the research was to observe the activities of two A. hydrophila’s enzymes i.e.: chitinase and lechitinase, and one extracelullar toxin, haemolycine, isolated from 30 nile tilapias cultured in floating net cage at Jatiluhur using quantitative plate assay technique. A. hydrophila was positive virulent marked with transparent zone of lechitinase of 7.9 mm, haemolycin of 6.6 mm, and chitinase of 8.0 mm compared to Enterobacter sp., Pseudomonas sp., and Vibrio sp. Therefore, A. hydrophila is determined as highly pathogenic bacterium and virulent for nile tilapia.