Isolasi Bakteri Asam Laktat dari Usus Ikan Kerapu Macan (Epinephelus fuscoguttatus) dan Potensinya Sebagai Antivibrio - Nursyirwani Nursyirwani; W. Asmara; A.E.T.H. Wahyuni; Triyanto Triyanto (Marine Science Department Diponegoro University, 2011)
Tujuan penelitian ini adalah untuk mengisolasi dan menguji potensi antibakterial bakteri asam laktat dari ikan Kerapu Macan (Epinephelus fuscoguttatus) terhadap bakteri patogen Vibrio alginolyticus. Bakteri tersebut diisolasi dari usus ikan dengan metode sebarulas pada media agar MRS dan GYP+CaCO3. Koloni yang tumbuh diidentifikasi berdasarkan karakter morfologi, biokimia dan fisiologi. Aktivitas antibacterial terhadap V. alginolyticus diuji dengan metode difusi kertas cakram pada media Zobell 2216E lapis ganda, diameter zona jernih disekitar kertas cakram diukur dengan kaliper. Pada medium agar GYP+CaCO3 didapatkan 21 isolat yang menampakkan zona jernih disekitar koloninya. Dari karakteristik morfologi, biokimia dan fisiologi dari isolat-isolat tersebut semua isolat dapat dikategorikan kedalam genus Lactobacillus. Tetapi, dari uji aktivitas antivibrio hanya 20 isolat menunjukkan zona hambat yang berkisar dari 14,0-21,5 mm, dimana tiga isolat menunjukkan aktivitas tertinggi, yaitu berturut-turut isolat KSBU 12C, KSBU 13D dan KSBU 5Da.Kata kunci: Isolasi, bakteri asam laktat, antivibrio, Kerapu Macan The objectives of this research were to isolate and examine antibacterial potency of lactic acid bacteria from Tiger Grouper (Epinephelus fuscoguttatus) against pathogen, Vibrio alginolyticus. The bacteria were isolated from the fish intestine by spread plate method on MRS and GYP+CaCO3 agar media. The grown colonies were identified based on morphological, biochemical and physiological characters. Antibacterial activity against V. alginolyticus was examined by the paper disc diffusion method on Zobell 2216E double layer agar, and clear zone diameter around the paper disc was measured by using caliper. Twenty one isolates with clear zone around the colonies were obtained from the GYP+CaCO3 agar. Morphological, biochemical and physiological characteristics of the colonies and cells indicated that all isolates might be categorized into Lactobacillus. However, there were only twenty isolates showed inhibition zones from 14.0-21.5 mm in antivibrio activity test, of which the highest activity was indicated by three isolates namely KSBU12C, KSBU 13D and KSBU 5Da, respectively. Key words: Isolation, lactic acid bacteria, antivibrio, Tiger grouper.