Optimizing fermentation conditions for fructosyltransferase enzyme production by Lactobacillus plantarum

Enzymatic production of fructooligosaccharides (FOS) from sucrose using β-D fructosyltransferase is commonly employed in commercial scale. FOS are low calorie sweetners with prebiotic property widely used as functional food material. In the present study, a strain of Lactobacillus plantarum (LABF 16) was found to produce bioactive oligosugars such as kestose and nystose exhibiting fructosyltransferase (FTase) enzyme activity. Further maximization of FTase production by the particular isolate was also attempted. The fermentation parameters viz., pH, temperature and sucrose concentration, which was found to influence the fructosyltransferase yield, were optimized by response surface methodology. The optimized conditions for the FTase production were pH 6.33, temperature of 32°C, sucrose concentration of 20.74 g/l, which resulted in an enzymatic activity of 129.62 U/ml/min.  Key words: Fructooligosaccharides, Lactobacillus, response surface methodology.