Functional Characterization and Antagonistic Activity of Lactic Acid Bacteria Isolates from the Caecum of Broiler Chickens against Staphylococcus aureus

Abstrak

The use of Antibiotic Growth Promoters (AGP) in poultry farms increases the risk of antibiotic resistance so alternatives such as probiotics are needed. This study aims to determine the functional characterization and antagonistic activity of Lactic Acid Bacteria (LAB) from broiler chicken caecum against Staphylococcus aureus. The test included an antagonistic test using the agar well diffusion method, acid tolerance at pH 1.5, 2,5, and 3,5, amylolytic, proteolytic, and hemolytic activity. The results showed that LAB had antagonistic activity against S. aureus with an average inhibition zone diameter of 3.87 mm in the weak category. The LAB isolate showed good survival under acidic conditions with a survival rate of 97.2% at pH 3.5, 94.5% at pH 2.5, and 91.4% at pH 1.5. The amylolytic test showed a negative result, while the proteolytic test was positive and the hemolysis test showed a type of γ-hemolysis, which indicates non-hemolysis. It was concluded that LAB of broiler caecum origin has antagonistic activity against S. aureus and is likely to be a potential probiotic candidate. Further research is recommended to conduct genotype-based molecular identification as well as more comprehensive testing of other probiotic characteristics.