Prebiotic fructooligosaccharide production from yeast strain ML1.
Fructooligosaccharides (FOS) are non-digestible oligosaccharides, mainly composed of 1-kestose (GF2), nystose (GF3) and 1 F-β-fructofuranosyl nystose (GF4), which are recognized as prebiotics because they can stimulate the bifidobacteria growth in the human colon. The aim of this work was to evaluate the factors affecting the production of fructooligosaccharides using sucrose as the substrate by a yeast strain ML1 isolated from sugarcane juice. The effects of sucrose concentrations (50-150 g/L), yeast extract concentrations (10-30 g/L) and agitation speeds (75-300 rpm) were studied in a 3L fermenter. It was found that sucrose concentration was the most effective parameter. This factor showed a positive influence on FOS yields. The optimized conditions for FOS production were 150 g/L sucrose, 20 g/L yeast extract with the agitation speed of 150 rpm. Under these controlled conditions, the maximum specific growth rate and the FOS concentration were obtained approximately 0.27 h-1 and 65 g/L, respectively.