Role of dissolved oxygen availability on lactobionic acid production from whey by Pseudomonas taetrolens

Abstract: The influence of dissolved oxygen availability on cell growth and lactobionic acid production from whey by Pseudomonas taetrolens has been investigated for the first time. Results from pH-shift bioreactor cultivations have shown that high agitation rate schemes stimulated cell growth, increased pH-shift values and the oxygen uptake rate by cells, whereas lactobionic acid production was negatively affected. Conversely, higher aeration rates than 1.5Lpm neither stimulated cell growth nor lactobionic acid production (22% lower for an aeration rate of 2Lpm). Overall insights into bioprocess performance enabled the implementation of 350rpm as the optimal agitation strategy during cultivation, which increased lactobionic productivity 1.2-fold (0.58–0.7g/Lh) compared to that achieved at 1000rpm. Oxygen supply has been shown to be a key bioprocess parameter for enhanced overall efficiency of the system, representing essential information for the implementation of lactobionic acid production at a large scale. [Copyright &y& Elsevier]