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The aim of this research was to study the ability of bacteriocin (amylocin) produced by Indonesian isolate of Lactic Acid Bacteria (LAB) (Lactobacillus amylovorus US 121) and its combination with nisin in pasteurized milk. The total bacteria was measured by plate count method. The antimicrobial activity of amylosin at 64 AU/ml had the same activity with nisin at 625 AU/ml and its combination between amylosin and nisin at 32 AU/ml and 312,5 AU/ml respectively against psychrotrophic, thermoduric bacteria and L. monocytogenes in pasteurized milk. However, combination of amylosin and nisin (32 AU/ml + 312,5 AU/ml) able to reduce S. aureus in pasteurized milk. Amylosin at 64 AU/ml kept the shelf life of pasteurized milk longer until 12 days at 10 o C. The addition of amylosin (the precipitate resulted by ammonium sulfate precipitation at 70% w/v) changed the color of pasteurized milk be brownish white.

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The objectives of this study were to assess the diversity of Newcastle Disease Virus (NDV) isolates; to detect and isolate NDV from poultry; and to identify and characterize NDV by serological and molecular assays. A total of 84 cloacal-oropharynx isolates of poultry was collected from privately owned poultries and poultry markets from 12 districts in Aceh Besar and Banda Aceh. Screening was performed by real time reverse transcriptation-polymerase chain reaction (rRT-PCR) to 15 isolates of poultry. Selected isolates were inoculated in 9-11 days old embryonated specific pathogen free (SPF) eggs and showed positive hemagglutination (HA). Characterization was performed through hemagglutination inhibition (HI) test using Komarov and Hitchner B1 antisera, elution test, RT-PCR and realtime RT-PCR fusion (F). All isolates had a higher affinity to Komarov antisera (titer up to 4 log), indicating virulent strain. This was supported by elution test which showed that 93.66% isolates were virulent and 6 % non-virulent. In conclusion, RT-PCR can detect Matrix gene from 15 isolates (100%), while Fusion gene only detected from 11 isolates (73.3%). rRT-PCR is more capable of detecting antigenic diversity compared to RT-PCR.