Influence of oxygen concentration on the metabolism of Penicillium chrysogenum

Abstract In large‐scale bioreactors, there is often insufficient mixing and as a consequence, cells experience uneven substrate and oxygen levels that influence product formation. In this study, the influence of dissolved oxygen (DO) gradients on the primary and secondary metabolism of a high produc...

Full description

Bibliographic Details
Main Authors: Agnes Janoska, Jelle J. Verheijen, Wenjung Tang, Queenie Lee, Baukje Sikkema, Walter M. van Gulik
Format: Article
Language:English
Published: Wiley-VCH 2023-01-01
Series:Engineering in Life Sciences
Subjects:
Online Access:https://doi.org/10.1002/elsc.202100139
Description
Summary:Abstract In large‐scale bioreactors, there is often insufficient mixing and as a consequence, cells experience uneven substrate and oxygen levels that influence product formation. In this study, the influence of dissolved oxygen (DO) gradients on the primary and secondary metabolism of a high producing industrial strain of Penicillium chrysogenum was investigated. Within a wide range of DO concentrations, obtained under chemostat conditions, we observed different responses from P. chrysogenum: (i) no influence on growth or penicillin production (>0.025 mmol L−1); (ii) reduced penicillin production, but no growth limitation (0.013–0.025 mmol L−1); and (iii) growth and penicillin production limitations (<0.013 mmol L−1). In addition, scale down experiments were performed by oscillating the DO concentration in the bioreactor. We found that during DO oscillation, the penicillin production rate decreased below the value observed when a constant DO equal to the average oscillating DO value was used. To understand and predict the influence of oxygen levels on primary metabolism and penicillin production, we developed a black box model that was linked to a detailed kinetic model of the penicillin pathway. The model simulations represented the experimental data during the step experiments; however, during the oscillation experiments the predictions deviated, indicating the involvement of the central metabolism in penicillin production.
ISSN:1618-0240
1618-2863