Investigation of Antagonistic effect of Lactobacillus acidophilus Isolated from the Gastrointestinal Tract of Oscar fish (Astronotus Ocellatus) on Pseudomonas aeruginosa

Document Type : Research Article


Department of Biology and Laboratory Science, Babol Branch, Islamic Azad University, Babol, Iran.


Among bacteria, lactic acid bacteria are the most common type of bacteria that have been introduced as probiotics. These bacteria are effective in treating rotavirus diarrhea, reducing blood sugar, blood pressure, cholesterol, preventing colon and small bowel cancer, liver, intestinal inflammation, infections, acute diarrhea, and the growth and proliferation of harmful bacteria, as well as causes to strengthen the immune system, help digestion and absorption of minerals and vitamins. In this research, samples were taken from 60 Oscar fish. To achieve this goal, lactic acid bacteria were duplicated by specific primer pairs, 16s rDNA gene of Lactobacillus acidophilus bacteria using PCR; and Lactobacillus acidophilus was identified using a specific band , and its antagonistic effect on Pseudomonas aeruginosa was investigated by disk diffusion methods, so that halo diameter equal to 1.4mm was observed at a dose of 50 μl. Then the MIC and MBC of each metabolite were determined. It was found that increasing the dose of Metabolite Lactobacillus acidophilus increases the effect on Pseudomonas aeruginosa.