Actinomycetes isolates used in this research were obtained from previous studies [20 , 21 ] that isolated from different regions in Indonesia. That previous studies stated that a soil dilution technique using Starch Casein Agar (SCA) was performed for the isolation of Actinomycetes. Pretreatment by heated at 50 °C for 1 h was done for all the sediment samples. Different dilutions (10− 2, 10− 3, and 10− 4) of the marine, river, and paddy field sediment suspensions were shaken under room temperature at 200 rpm for 1 min, then 100 μL of each suspension were spread onto SCA medium and incubated at 28 °C for 7 days. Isolates from that previous studies were grown onto Yeast Malt Extract Agar (YMEA) (Oxoid) and incubated at 28 °C for approximately 7 days. Indicator bacteria C. violaceum wild type was cultivated onto Luria-Bertani Agar (LA) (Oxoid) and incubated at 28 °C for 2 days. Food spoilage bacteria B. cereus ATCC 10876, B. subtilis ATCC 6633 were streaked onto LA and incubated at 37 °C 24 h, meanwhile S. putrefaciens ATCC 8071 was streaked onto Tryptone Soya Agar (TSA) (Oxoid) and incubated at 28 °C 24 h. All the bacteria used in this research came from Atma Jaya’s culture collection.
Free full text: Click here
