Comparative investigation of fine bubble and macrobubble aeration on gas utility and biotransformation productivity

Benjamin Thomas, Daniel Ohde, Simon Matthes, Claudia Engelmann, Paul Bubenheim, Koichi Terasaka, Michael Schlüter, Andreas Liese

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)


The sufficient provision of oxygen is mandatory for enzymatic oxidations in aqueous solution, however, in process optimization this still is a bottleneck that cannot be overcome with the established methods of macrobubble aeration. Providing higher mass transfer performance through microbubble aerators, inefficient aeration can be overcome or improved. Investigating the mass transport performance in a model protein solution, the microbubble aeration results in higher kLa values related to the applied airstream in comparison with macrobubble aeration. Comparing the aerators at identical kLa of 160 and 60 1/h, the microbubble aeration is resulting in 25 and 44 times enhanced gas utility compared with aeration with macrobubbles. To prove the feasibility of microbubbles in biocatalysis, the productivity of a glucose oxidase catalyzed biotransformation is compared with macrobubble aeration as well as the gas-saving potential. In contrast to the expectation that the same productivities are achieved at identically applied kLa, microbubble aeration increased the gluconic acid productivity by 32% and resulted in 41.6 times higher oxygen utilization. The observed advantages of microbubble aeration are based on the large volume-specific interfacial area combined with a prolonged residence time, which results in a high mass transfer performance, less enzyme deactivation by foam formation, and reduced gas consumption. This makes microbubble aerators favorable for application in biocatalysis.

Original languageEnglish
Pages (from-to)130-141
Number of pages12
JournalBiotechnology and bioengineering
Issue number1
Publication statusPublished - 2021 Jan


  • aeration technology
  • gas utilization
  • glucose oxidase
  • microbubbles
  • multiphase reaction

ASJC Scopus subject areas

  • Biotechnology
  • Bioengineering
  • Applied Microbiology and Biotechnology


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