Isolation and Identification of Lactic Acid Bacteria from Fee Range Chahua Chickens and Their Probiotic Properties

Purpose In this study, we investigated the probiotic properties of lactic acid bacteria derived from national protected species of the genetic resources of livestock and poultry, Chahua chickens, in order to provide solid base to the potential microbial agent applied in poultry production.

Method Fecal samples of free range Chahua chickens were collected and MRS medium was used to isolate suspected lactic acid bacteria. The strains were subjected to physiological and biochemical tests and 16S rDNA sequence analysis. The probiotic properties of these isolates including resistance to gastrointestinal conditions, antimicrobial activity, susceptibility to antibiotics, and adhesive ability to intestinal epithelial cells were determined.

Results Four strains including CHF4-1, CHF6-2, CHF7-2 and CHF10-2, were isolated. According to the physiological and biochemical identification and 16S rDNA sequence analysis, CHF6-2, CHF10-2, CHF7-2 and CHF4-1 were identified as L. gasseri, L. johnsonii, L. reuteri, and L. salivarius, respectively. Compared with the reference strain L. rhamnosus GG, both L. gasseri CHF6-2 and L. johnsonii CHF10-2 showed greater gastrointestinal tolerance and higher antimicrobial activity. Except being intermediately susceptible to cefotaxime,L. gasseri CHF6-2 was susceptible to the other tested antibiotics. Adhesion ability ofL. gasseriCHF6-2 was the best among these LAB strains with the index of 13.07 ± 0.22.

Conclusion Four LAB strains were isolated from fecal sample of Chahua chickens and L. gasseri CHF6-2 showed the best probiotic properties including good gastrointestinal tolerance, higher antimicrobial activity, antibiotic susceptibility and effective adhesion to intestinal epithelial cells. L. gasseri CHF6-2 has the potential to be a probiotic candidate and further study is needed to determine its application in poultry production.