Screening Probiotic Properties Of Lactic Acid Bacteria In Jiangshui

In this paper,91 strains of Lactobacillus were isolated and purified from the Jiangshui of Shaanxi,Henan and other places.The main results are as follows:91 strains were isolated and divided into:36 strains of Lactobacillus brevis,48 strains of Lactobacillus plantarum and 7 strains of Lactobacillus parabuchneri.G11 can tolerate nitrite less than 400 mg/L and have a high removal rate(>96.44%).Nitrite(500 mg/L)was degraded more than 80%(89.86%)in 24 h.It shows the higher ability of nitrite degradation.The results showed that the inhibition rate of 91 strains:85.71%of strains had more than 80%for E.coli.98.9%of strains had more than 80%for Pseudomonas aeruginosa;25.27%of strains had more than 80%for Staphylococus aureus;72.52%of strains had more than 80%for Bacillus subtilis.Among them,G7 had the highest average inhibition rate(90.29%).The other probiotic functions of 32 strains with strong comprehensive probiotic ability were determined.Acid resistance:62.5%of strains were more than 90%(p H 3.0).Bile salt tolerance:at the concentration of 0.5%bile salt,62.5%strains were more than 1.0×10~6(colony forming unit;CFU)/m L,and the survival rate of G11 was 61.43%.The self aggregation rate of 50%strains was more than 90%,the highest was F6(98.94%),which indicated that these strains had the potential to colonize intestinal tract.The degradation rate of G8 to cholesterol reached30.63%.The degradation rate of the other five strains more than 20%.Among 11 strains can produce?-aminobutyric acid,A12 was the best.And all strains have the ability of producing acid and producing exopolysaccharide.It was found that 18 strains of 32 strains were not hemolytic,including 5 strains with better probiotic function(E12,G6,G8,G11 and H1).In the test of antibiotic resistance,all of the five strains were sensitive to 5 kinds of antibiotics such as erythromycin,and resistant to 4 kinds of antibiotics such as vancomycin.By comprehensive analysis of all probiotics,G11 has the ability of removing nitrite and cholesterol efficiently,bacteriostasis,acid and bile salt resistance.However,G6 and G8 had higher antibacterial activity(>80%)and cholesterol removal rate(21.89%and 30.63%).H1had better ability to remove nitrite(80 mg/L;95.49%)and cholesterol(29.77%).All of these strains have the ability of exopolysaccharide and acid production.They are not hemolytic and sensitive to erythromycin and other antibiotics,showing multiple probiotic functions,and have the potential to be used in food industry.