DOI: 10.36347/sajb.2020.v08i09.006

Pages: 301-308

Lactic acid bacteria (LAB) are mostly explored for probiotic activities. These organisms improve the organoleptic characteristics of food, inhibit microbial activities, and consequently prevent possible diseases. The aim of this study, therefore, is to investigate organisms with possible inhibitory action against pathogenic bacteria. Besides, Papuan red fruits obtained from Sorong (West Papuan) and Timika (Papuan) were estimated to contain LAB, hence samples were selected and isolated using de Man Rogosa Sharpe selective medium equipped with 1% CaCO3. The organisms were then analyzed based on acid sensitivity (pH 2, 3, and 4) and bile tolerance (0.3%; 0.5% and 1%). The antibacterial activity was evaluated using well diffusion method on the Muller Hilton Agar medium against pathogenic bacteria Staphylococcus aureus ATCC 25923, Salmonella typhi BPE 122.4 CCA, and Salmonella typhi NCTC 786. The identity of LAB isolates was confirmed based on the API 50CHL test, and a total of 25 isolates were successfully selected. These were characterized based on the cellular properties of rod-shaped, Gram-positive, homofermentative, non-motile, catalase-negative, as well as the capacity to grow at 10ºC and 45ºC. Furthermore, five of the isolates (strains S1B1, S2B1, S1T2, S2T4, and S1T1) were identified as Lactobacillus plantarum, with the ability to survive at pH 2 and in 1% bile salts. The antibacterial activity of the S2T4 strain was strong against S. aureus ATCC 25923, S. typhi BPE 122.4 CCA, and S. typhi NCTC 786. Besides, LAB S2B1 significantly restrained the growth of Salmonella typhi BPE 122.4 CCA, while LAB S1T1 inhibited S. aureus ATCC 25923. Therefore, it is possible to further explore Lactobacillus plantarum strains S2T4, S2B1, and S1T1 for the inherent health and nutritional values.