RESUMEN
Lactic acid bacteria are characterized as gram-positive, usually non-motile, non-sporulating bacteria that produce lactic acid as a major or sole product of their fermentative metabolism. In this study, the presence of lactobacilli were investigated in the intestines of beluga [Huso huso] and Persian sturgeon [Acipenser persicus], inhabiting Caspian sea. The obtained data showed that various species of lactobacilli populations were found at high levels in the intestines of fishes. Total number of lactobacilli was about 10[5.3] and 10[6.4] cfu/g of intestinal content for beluga and Persian sturgeon, respectively. Physiological and biochemical characteristics of 84 strains isolated from intestines of beluga and Persian sturgeon revealed that these strains can be categorized into 2 metabolic groups; facultative and obligate heterofermentatives. The most common presumptive lactobacilli species were Lactobacillus sakei and Lactobacillus plantarum. The current study is the first report on the isolation of lactobacilli from the intestine of beluga and Persian sturgeon