Fig. 2 Time course of overall biomass, glucose and rhamnolipid masses (sum of bioreactor and integral foam fractions) during foam fractionation process.
Fig. 1 Setup for integrated foam fractionation in a bioreactor.
Two strategies of fermentation coupling with foam fractionation were designed.
Comparing foam fractionation parameters of the rhamnolipid process with the surfactin process a high effectiveness of the integrated foam fractionation for rhamnolipid production was demonstrated.
However, fermentations employing foam fractionation still yield higher YP/S values (0.052 g/g).
Aerobic processes applying foam fractionation yield rather similar results for qSurfactin (0.006 g(g∙h)).
Most interesting, the product yields exceeded classical aerobic fermentations, in which foam fractionation was applied.
Foam fractionation is an elegant method for in situ product removal when producing microbial surfactants.
These findings surpass even YP/X values of aerobic fermentations employing foam fractionation (0.192 g/g).
So far no cultivation integrated foam fractionation process for rhamnolipid production has been reported.
Methods were adapted from foam fractionation processes as described in Beuker et al. (2016).
