Development of Efficient Fermentation Process at Bioreactor Level by Taguchi's Orthogonal Array Methodology for Enhanced Dextransucrase Production from <i>Weissella confusa</i> Cab3

Abstract

The influence of medium ingredients on extracellular dextransucrase production by a new bacterial strain Weissella confusa Cab3 (Genbank Accession Number JX649223) was evaluated using fractional factorial design of Taguchi's orthogonal array. Four metabolism influencing factors viz. sucrose, yeast extract, K 2 HPO 4 and Tween80 were selected to optimize dextransucrase production by W. confusa Cab3 using fractional factorial design of Taguchi methodology. Based on the influence of interaction components of fermentation, least significant factors of individual level have higher interaction severity index and vice versa for enzyme production from Weissella confusa Cab3. Sucrose and yeast extract were found to be the most significant factors which positively influenced the dextransucrase production. The optimized medium composition consisted of sucrose-5%; yeast extract-2%; K 2 HPO 4 -1.0%; Tween80-0.5, based on Taguchi orthogonal array method. The optimized composition gave an experimental value of dextransucrase activity of 17.9 U/ml at shake flask level which corresponded well with the predicted value of 17.54 U/ml by the model. The optimized medium by Taguchi method gave significant (3 fold) enhancement of dextransucrase activity as compared to unoptimised enzyme activity of 6.0 U/ml. The dextransucrase production was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml).

Oxygen transfer rate modulates the dextransucrase production by Acetobacter tropicalis

“…Landon [28] studied effect of stirring on dextransucrase production for Leuconostoc mesenteroides NRRL B512 (F) and suggested some limitations in difussion through cell membrane in static culture. Recently, dextransucrase production by a new bacterial strain Weissella confusa Cab3 was scaled up in lab scale bioreactor resulting in further enhancement of enzyme activity (22.0 U/ml) than shake flask level of 17.54 U/ml [29].The dextransucrase activities in excess of 21.9 U/ ml have also been obtained by culturing L. mesenteroides NRRL B512(F) under non-aerated fed-batch fermentation conditions [30]. However, Santos et al, [20] found that aeration does not have an important effect in fermentation by L. mesenteroides NRRL B512(F).…”