Abstract:The aim to explore the bile salt deconjugation ability of lactic acid bacteria (LAB) strains from traditional fermented dairies in Western China included Qinghai, Gansu, Xinjiang, Tibet and Inner Mongolia, to provide reference for the effective development of microbial resources. The bile salt deconjugation ability of 275 LAB strains isolated from western traditional fermented dairies were determined by HPLC, analysis the different bile salt deconjugation ability among the different species and isolates’ sources, screening excellent strains. At the same time, the ability to produce γ-aminobutyric acid was determined for the selected strains, which provided a reference for the exploration of new resources of lactic acid bacteria and industrial production of gamma-aminobutyric acid. The results showed that, ①83 LAB strains were with bile salt deconjugation ability, and there had differences of isolating rates among different sources and species, Tibetan milk dregs showed a higher positive strain screening rate, strains L. paracasei, L. plantarum, L. breris and L. casei showed higher positive strains screening rate. ②There were significant differences of the bile salt deconjugation ability for GCA, GDCA, GCDCA, TDCA, TCA and TCDCA among all the BSH-positive strains (P<0.05), the deconjugation ability of glycine conjugating bile salt of were higher than taurine conjugating bile salt. ③For the different regions, there were significant differences of 4 bile salt deconjugation index in different areas BSH-positive strains, the dissociation capacity of bile salts from positive strains from Xinjiang and Tibet was significantly higher than that from Qinghai and Inner Mongolia (P<0.05). ④ For the different types of fermented dairies, there were significant differences of 3 bile salt deconjugation index in different dairies BSH-positive strains, the dissociation capacity of total bile salts in the positive strains in milk residue was significantly higher than that in acid horse milk and acid milk (P<0.05). ⑤For the different dominant BSH-positive strains, there were significant differences of 5 bile salt deconjugation index in different dominant strains, the dissociation ability of L. breris and L. plantarum to total bile salts was significantly higher than that of L. paracasei and L. casei (P<0.05). ⑥Analysis of ability of four excellent strains to produce γ-aminobutyric acid: L. breris and L. plantarum have higher γ-aminobutyric acid capacity, while L. paracasei and L. casei do not produce γ-aminobutyric acid. In conclusion, because of different species and isolates’ sources, the bile salt deconjugation ability for LAB stains were different. For the different sources, isolates from Koumiss, Shubat in Xinjiang and milk dreg in Tibet was with the highest bile salt deconjugation ability. For the different dominant strains, L. breris and L. plantarum was with the higher bile salt deconjugation ability, and it has the ability to produce high γ-aminobutyric acid, which can provide a theoretical basis for the development of excellent lactic acid bacteria species.