Effect of cultivation conditions on the yield and proportion of exopolysaccharide fractions produced by Bifidobacterium

Abstract:

[Objective] Exopolysaccharides produced by Bifidobacterium animalis RH were fractionated into two peaks by anion exchange chromatography, named as EPSa and EPSb. The aim of the study was to obtain the optimal conditions for high yield of total EPS, especially EPSb. [Methods] In this paper, the effects of medium types, nitrogen source, carbon source, carbon concentration, initial medium pH, cultivation temperature and cultivation time on the yield and proportion of EPSa and EPSb were evaluated. [Results] The highest yield and favorable proportion were obtained in PTYG broth medium (pH 7.0) containing 5% sucrose when B. animalis RH was anaerobically cultivated at 35 °C for 60 h. [Conclusion] Under these conditions, the yield of EPSa and EPSb were 0.982±0.003 g/L and 0.312±0.001 g/L, respectively.