study of probiotic potential of lactic acid bacteria isolated from the digestive system of Astronotus ocellatus fish

Lactic acid bacteria are the most common types of bacteria that have been introduced as probiotics. The present study was carried out to lactic acid bacteria isolated from the Astronotus ocellatus and to investigate their resistance to bile salts, tolerance to acidic conditions and the ability fermentation of sugars. In this research, 50 fish were sampled and cultured in MRS culture medium in order to achieve this goal. The lactic acid bacteria were isolated by phenotypic methods (Gram staining, biochemical tests). and their probiotic properties were evaluated. Then, furder identification was performed by using a pair of specific primers, the 16s rDNA gene of Lactobacillus acidophilus, Lactobacillus casi, which was amplified using PCR.Using a specific bond, the bacterial species identified as a lactic acid. At the end of study, after staining and PCR testing, 21 samples from L.acidophilus and 18 Lcases of L. casei were identified from 50 samples.