Showing papers by "Adam Harvey published in 2009"

The Production of Polyhydroxyalkanoates using an Oscillatory Baffled Bioreactor

Abstract: Oscillatory baffled reactors (OBRs) are a form of plug flow reactor that can be used for long reactions, as the plug flow is not dependent on achievement of a certain velocity in the reactor leading to much more compact designs. One class of long reactions is that of bioreactions/fermentations. Since one major advantage of the OBR is its highly uniform, controllable mixing, which can be used to enhance gas-to-liquid mass transfer, it should be suitable for biological reactions. Continuous fermentation is a second advantage, as it should minimise substrate and product inhibition. Lower, more uniform shear rates than in a stirred tank reactor would be an additional advantage for processing shear-sensitive cells. Previous research has shown that the OBR can provide higher biomass concentrations and greater gasliquid mass transfer than conventional fermenters. In this work, the production of polyhydroxyalkanoates (PHA) by Pseudomonas putida was investigated. The parameters investigated here were agitation, aeration rate and temperature. Additionally, various media were investigated to determine the effect on yield. It was demonstrated that PHA can be produced in the OBR. The optimum fermentation temperature and agitation rate for PHA production in this parameter space were determined. It was also demonstrated that using an OBR can lead to higher OD and dry cell weight than a conventional stirred tank reactor.