Antibiotic Susceptibility Profiles and Potential of Lactic Acid Bacteria from Dadih as Antimicrobial Producers and Dangke Whey Fermenters

We aimed to explore the potential of lactic acid bacteria (LAB) indigenous Dadih (Indonesian traditional fermented buffalo milk) as antimicrobial producers and to see their ability as Dangke whey fermenters. Nine isolates belonging to Lactobacillus plantarum (designed as LP007, LP021, and LP050), Lacticaseibacillus paracasei (LC028, LC039, and LC040), and Levilactobacillus brevis (LB025, LB042, and LB055) were used in this study. Antagonistic activity was performed to evaluate the antimicrobial activity in inhibiting Escherichia coli, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus from ATCC strain and field resistant strains. The susceptibility test was conducted to evaluate the LAB sensitivity profile to sixteen antimicrobials. Furthermore, the potential of L. plantarum, L. paracasei, and L. brevis was observed to see their ability as Dangke whey fermenters (a byproduct from Indonesian traditional cheese). The results showed that LAB isolates are generally greater in inhibiting Gram-negative than Gram-positive bacteria. Particularly, L. plantarum showed strong activity against ATCC strains and intermediate-strong level to antibiotic field-resistant strains. Nevertheless, all strains showed the ability to produce antimicrobial products. Our results also showed that L. plantarum LP007 revealed the lowest resistance profile as a potential probiotic. In addition, L. plantarum, L. paracasei, and L. brevis could ferment Dangke whey at 37°C in 24-48 h incubation. In conclusion, studied LAB isolates showed ability as antimicrobial producers, and this study presents the variety of LAB species that can be used as Dangke whey starters.