Fermentation of pullulan using an oscillatory baffled fermenter

The oscillatory baffled reactor offers enhanced and uniform mixing at very low shear rates compared to conventional mixing devices. This is advantageous for biochemical and biomedical applications where shear sensitive cultures are involved. The work in this paper explores the way in which Aureobasidium pullulans, which produces the versatile biopolymer pullulan, behaves in the low and uniform shear environment of an oscillatory baffled fermenter (OBF), and compares its growth rate and pattern to those in traditional fermenters. A series of pullulan fermentation experiments were performed in the OBF with a particular emphasis placed on the influence of aeration on pullulan and biomass production. The results show that at the optimal volumetric airflow rate of 1 vvm (volume of air per volume of liquid per min) the performance of the OBF is significantly better than the traditional stirred tank fermenter. © 2005 Institution of Chemical Engineers.