Immobilization of Bifidobacterium breve by Entrapment in Alginate Beads Survival against Environmental Stress

초록

Bifidobacteria have shown to play an important beneficial roles on the human host. However, they are sensitive to acidic pH, oxygen and thus would not be expected to survive in the stomach and acidified dairy products such as yoghurt. In this study, Bifidobacterium breve cells were entrapped in beads of calcium alginate, using both two phase(water/oil) technique. The entrapped cells were evaluated for their ability to survive under acidic condition and hydrogen peroxide. In addition, various parameters of the entrapment processes were investigated. Three process parameters were selected for testing; sodium alginate concentration, bead size and retreatment. The best survivability was obtained with beads 3.30mm of diameter made at 4% alginate. Especially, the number of viable cells in the retreatmented beads was 100 fold higher than non-entrapped cells in calcium alginate beads lost only 46.55% of viability after 5 hours, 4℃ storage period with hydrogen peroxide(1,000 ppm), These experimental data demonstrate that immobilization of B. breve by entrapment in alginate beads promotes survival aginst environmental stresses such as the acidic condition and hydrogen peroxide.