Production of Exopolysacchardies by Probiotic Bacteria in the Presence of Bile Acids

الملخص

Introduction: Exopolysaccharides (EPS) are compounds that contain one or two types of monosaccharide. They are synthesized by some strains of bacteria during fermentation stage; they contribute to the improvement of health by improving the Rheological properties of fermented dairy products. Objective: This study aimed to determine the ability of some bacteria to produce EPS in different Medias. Methods: In this study, three strains of bacteria (Bifidobacterium bifidus actiregulari, lactobacillus delbrueckii subsp.bulgaricu and Streptococcus thermophilus were examined to evaluate their ability to grow and produce Exopolysaccharides in the presence of bile acids (Na-cholic and Na-dexoycholic Acid (50:50%)) in different concentrations. Results: All tested bacterial strains were grown in the low and moderate concentrations of bile acids, while its growth was particularly inhibited with the presence of high concentration of bile acids. The results also show that all of the experiment strains produced different quantities of exopolysaccharides in different media cultures. The production of exopolysaccharides was ranged from 100 to 560 mg/l, and it was associated with bacterial growth. Conclusion: Bacterial strains in this study have high ability to produce EPS in the presence of bile acids.