Optimization of multiple valuable biogenic products using experimental design

Abstract

During the last few decades, biosurfactants (e.g. rhamnolipids) have received much more attention as an alternative to the conventional synthetic surfactants. The production cost of biosurfactant is the main hindrance for its commercialization. The production of multiple valuable products in a single process may contribute in reduction of the production cost. The scope of the current work was to use Plackett Burman design for selection of the most significant factors with highest contributionsfor production of rhamno lipids in parallel with protease using Pseudomonas aeruginosa (PAO1). Nineteen factors have been selected for this study. According to the obtained results, six obvious factors; glucose, casein, peptone, yeast extract, pH and NaCl, had to be added to the production medium and three others; urea, NaNO₃, and (NH₄)₂SO₄, should not. Some of the remaining factors were not significant and the others had contrary effects on rhamnolipids and protease production. The final results showed that, the use of factorial design resulted in 213.27% increase in rhamnolipid productivity and 296.65% increase in protease productivity compared with the original production conditions.