ISOLASI DAN SELEKSI BAKTERI ASAM LAKTAT PENGHASIL SENYAWA ANTIMIKROBA DARI LELE DUMBO (Clarias gariepinus) TERHADAP Aeromonas hydrophila, Edwardsiella ictaluri DAN Staphylococcus aureus

Oleh :
Slamet Mardiyanto Rahayu - M0402044 -

Isolasi dan Seleksi Bakteri Asam Laktat Penghasil Senyawa Antimikroba dari Lele Dumbo (Clarias gariepinus) terhadap Aeromonas hydrophila, Edwardsiella ictaluri, dan Staphylococcus aureus Isolation and Selection of Lactic Acid Bacteria Producing Antimicrobial Substance from King Catfish (Clarias gariepinus) against Aeromonas hydrophila, Edwardsiella ictaluri, and Staphylococcus aureus Slamet Mardiyanto Rahayu1 , Ratna Setyaningsih2 , Yantyati Widyastuti 3 Jurusan Biologi. Fakultas MIPA. Universitas Sebelas Maret Surakarta Puslit Bioteknologi LIPI-Cibinong, Bogor Lactic acid bacteria can be found in a lot of habitats such as fermented food or drink, fruits and gastrointestinal of humans or animals. Lactic acid bacteria play an important role in the inhibition of pathogenic microorganism so they can be used for increasing the health of humans or animals. The aims of the research were (1) to get lactic acid bacteria isolates from gastrointestinal of king catfish (C.gariepinus), (2) to get lactic acid bacteria isolates that produced antimicrobial substance against A.hydrophila, E.ictaluri, and S.aureus, and (3) to identify the potencial isolates of lactic acid bacteria wich produced antimicrobial substance against A.hydrophila, E.ictaluri, and S.aureus. The experiment was carried out by collecting the samples of king catfish (C.gariepinus) from region of Depok and Parung, Bogor. Isolation of lactic acid bacteria were carried of using MRS medium containing 0.5% CaCO3. Lactic acid bacteria isolates then identified based on Gram reaction, catalase test, and cell motility test. Selection of lactic acid bacteria isolates produced antimicrobial substance against A.hydrophila, E.ictaluri, and S.aureus was carried out well-agar diffusion method. Selection of lactic acid bacteria isolates included against activity of culture, acid supernatant, and neutral supernatant. Identification for lactic acid bacteria potencial isolates was carried out followed the procedure of Gram reaction, biochemical test, and physiological test. As the results, 83 isolates of lactic acid bacteria was collected. Seven isolates, DUB2B4, DUK3B14, DUB2B6, DUB1B8, DUK3B13, PUB1B, and PUB1B3, were selected as potencial isolates. Two isolates, DUB2B4 and DUK3B14 were selected as top potencial isolates which showed the wide antimicrobial spectrum. The best activity of culture, acid supernatant, and neutral supernatant isolate DUB2B4 against A.hydrophila were 6.358 x 103 mm2 /ml; 3.972 x 103 mm2 /ml; and 3.454 x 103 mm2 /ml respectively. The best activity of culture, and acid supernatant isolate DUK3B14 against A.hydrophila were 5.714 x 103 mm2 /ml; and 2.967 x 103 mm2 /ml respectively. The best activity of neutral supernatant isolate DUK3B14 against E.ictaluri was 2.512 x 103 mm2 /ml. Primary identification shows that isolate DUB2B4 was Lactobacillus sp. and isolate DUK3B14 was Enterococcus sp.