The qualities of lactobacilli in the gastrointestinal (GI) tract of broiler chickens were screened for probiotic applications. The GI content of twelve broiler chickens, of three different ages, were collected and cultured in MRS agar. In order to determine their species, different colonies were separated and subjected to sequencing of the 16s ribosomal DNA fragment. An auto-aggregation test was performed for 39 isolated lactobacilli bacteria. Eight species were selected due to their convenient aggregation. Some specific test for probitics were performed such as resistance to low pH, resistance to bile extract, ability to produce H2o2 production, cell surface hydrophobicity and adhesion activities on crop epithelial cells. Some bacteria showed suitable results in some tests while in other tests unsatisfactory results were produced. Therefore, after studying all aspects of the probiotic traits, L.crispatus caeca10 was selected, since this species showed acceptable results in all criteria. Because of the experiments were conducted in an in vitro condition, it was suggested that L.crispatus caeca10 be evaluated in an in vivo condition.

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