Design and characterization of a one-compartment scale-down system for simulating dissolved oxygen tension gradients

✍ Scribed by Antonio De León-Rodríguez; Enrique Galindo; Octavio T. Ramírez

• Publisher: Wiley (John Wiley & Sons)
• Year: 2010
• Tongue: English
• Weight: 292 KB
• Volume: 85
• Category: Article
• ISSN: 0268-2575
• DOI: 10.1002/jctb.2384

✦ Synopsis

Abstract

BACKGROUND: A laboratory scale one‐compartment scale‐down system (1‐CSDS), used to generate dissolved oxygen tension (DOT) gradients was designed and characterized. The system consists of a 1.5‐L stirred‐tank bioreactor coupled to an automatic DOT controller that changes the oxygen partial pressure in the inlet gas through a feedback proportional–integral–derivative algorithm, while maintaining the hydrodynamic conditions constant. Oscillatory control of DOT was achieved by employing time‐dependent square wave or sinusoidal setpoints.

RESULTS: The 1‐CSDS can be modeled as a first‐order dynamic system, but showing a permanent lag between the system response and the setpoint. The 1‐CSDS had a faster response rate for generating oscillating DOT when a square wave setpoint was used rather than a sinusoidal setpoint. The 1‐CSDS generated symmetric DOT oscillations at periods above of 100 s.

CONCLUSION: The 1‐CSDS is suited to investigate the responses of microorganisms and cells, of biotechnological importance, to oscillatory DOT conditions. It was found that the response of the 1‐CSDS was limited by the k~L~a. Copyright © 2010 Society of Chemical Industry