Screening of Bifidobacterium strains with High Yield of γ-Aminobutyric Acid and Its Improvement in Depressive Cell

In order to screen out strains which have depressing effect,parameters including bile salt hydrolase activity,antibiotic resistance,stress resistance and adhesion in 94 Bifidobacterium strains were used as basic indicators for probiotic evaluation;high-yield gamma-aminobutyric acid(GABA)content was as a screening indicator for potential antidepressant strains. Additionally,the in vitro depressive cell model test was used to study the improvement effect of strains on the depression cell model,and then evaluate the potential of the strain to improve depression. The results showed that 13 Bifidobacterium strains had higher BSH activity. However,13 Bifidobacterium strains did not have antibiotic resistance other than species-specific tolerance. The acid-resistant and bile-resistant salt experiments proved that Bifidobacterium ZT3,84 and 95 had high resistance against various stress;Moreover,the adhesion results showed that Bifidobacterium 91,92,95 and 98 had strong adhesion ability,with the value of 19.34,33.77,23.23 and 20.46 CFU/Cell,respectively. The results of GABA test of 13 Bifidobacterium strains showed that the yield of GABA of Bifidobacterium 98 and 95 had the ability at high dose. The results of the depressive cell model test showed that high,medium and low doses of GABA-producing Bifidobacterium 98 all had the ability to alleviate CORT-induced cell damage,while Bifidobacterium 95 was dose-dependent to alleviate cell damage. Given that Bifidobacterium 98,95 has a safe antibiotic tolerance range,high acid,bile salt tolerance and adhesion,as well as high ability to produce GABA and alleviate cell model damage,the stain can be promising for improving in depressive symptoms.