<![CDATA[Protein ekstraseluler (ECP) bakteri memiliki kemampuan imunogenik dan dapat meningkatkan sistem imun tubuh inang. Komponen ECP diantaranya flagellin, protease dan metalloprotease mampu berdifusi pada sel inang untuk mengaktifkan respon imun. Tujuan penelitian adalah untuk mengetahui produksi protein ekstraseluler E. tarda dengan presipitasi ethanol pada konsentrasi berbeda sebagai potensi protein imunogenik secara in vitro. Metode penelitian yaitu kultur bakteri E. tarda, preparasi protein ekstraseluler, presipitasi protein, konsentrasi protein ditentukan denganspektrofotometer dan SDS-PAGE, uji in vitro protein ECP E. tarda, dan uji nilai RPS. Hasil protein ekstraseluler yang diperoleh dengan presipitasi ethanol tertinggi pada konsentrasi 90% sebanyak 5,69 mg/ml dan terendah pada konsentrasi 80% sebanyak 4,81 mg/ml. Hasil karakterisasi protein dengan SDS-SDSPAGE antara 30-60 kDa. Hasil uji in vitro vaksin E. tarda (presipitasi ethanol 100%) baik dari uji viabilitas maupun sterilitas menunjukkan tidak terdapat koloni yang tumbuh. Hasil nilai RPS pada ikan nila (Oreochromis niloticus) mencapai 100% dengan masa pemelihaaraan 9 hari pasca imunisasi. ECP bacteria have immunogenic abilities and can increase the host's immune system. ECP components which are flagellin, protease, metalloprotease can diffuse to host cell for the activation immune response. The study aimed to determine the production of extracellular protein E. tarda with ethanol precipitation at different concentrations as a potential immunogenic protein by in vitro test. The research methods were E. tarda bacterial culture, extracellular protein preparation, protein precipitation, protein concentration determined by spectrophotometer and SDS-PAGE, in vitro ECP E. tarda protein test, and RPS value test. The results of extracellular protein obtained by the highest ethanol precipitation at a concentration of 90% as much as 5.69 mg/ml and the lowest at 80% concentration as much as 4.81 mg/ml. The results of the characterization of proteins with SDS-SDS-PAGE between 30-60 kDa. The results of the in vitro test of E. tarda vaccine (100% ethanol precipitation) from both the viability and sterility tests showed that there were no growing colonies. The results of the RPS in tilapia (Oreochromis niloticus) reach 100% with a maintenance period of 9 days after immunization.]]>
