Boosting extracellular dextransucrase production by Weissella confusa by combining a statistical and randomized mutational approach during upstream fermentation processing

Abstract

Statistical approaches have been established for optimizing fermentation practices and because of encouraging outcomes of these methods, several industries are harmonising in using them for maximum productivity of biological metabolites. Statistical methods are feasible and reliable in performing experiments and analysing results as compared to conventional bioprocessing methodologies. Similarly, strain improvement is also a significant strategy. In the current study, combinatorial approach that involves combining of classical mutagenesis and statistical optimization is attempted to scale-up productivity levels of dextransucrase. Enzyme productivity increased 2.56-fold as compared to wild-type. Plackett-Burman design revealed fermentation temperature, sucrose and peptone concentrations as significant factors. Response surface methodology further enhanced enzyme yield from 29.2 DSU ml−1 to 96.9 DSU ml−1. Overall results revealed remarkable improvement in dextransucrase yield (8.5-fold) depicting significance of currently designed combinatorial approaches. Dextran was produced after this statistically proven approach and based on its structural features its diversified applications are suggested.

Keywords

• Combinatorial approach
• dextransucrase
• mutation
• response surface methodology
• Weissella confusa