A scalable bubble‐free membrane aerator for biosurfactant production

Abstract

The bioeconomy is a paramount pillar in the mitigation of greenhouse gas emissions and climate change. Still, the industrialization of bioprocesses is limited by economical and technical obstacles. The synthesis of biosurfactants as advanced substitutes for crude‐oil‐based surfactants is often restrained by excessive foaming. We present the synergistic combination of simulations and experiments towards a reactor design of a submerged membrane module for the efficient bubble‐free aeration of bioreactors. A digital twin of the combined bioreactor and membrane aeration module was created and the membrane arrangement was optimized in computational fluid dynamics studies with respect to fluid mixing. The optimized design was prototyped and tested in whole‐cell biocatalysis to produce rhamnolipid biosurfactants from sugars. Without any foam formation, the new design enables a considerable higher space–time yield compared to previous studies with membrane modules. The design approach of this study is of generic nature beyond rhamnolipid production.

Environmental Impacts of Biosurfactant Production Based on Substrates from the Sugar Industry

“…Essential data for the modeled foreground processes were determined by laboratory tests and larger experimental setups. The underlying data and knowledge are much more advanced for RLs than for MELs due to previous RL-focused work by project partners. ,− In addition to project data, background processes like electricity supply or production of auxiliary materials were taken from the established and frequently used ecoinvent 3.7 database and GaBi professional database. , Furthermore, the literature (e.g., Spörri et al, Knoll), statistical data (e.g., animal feed from sugar beet), and own calculations (e.g., tank design) were used. − Data for the substrates’ supply were taken from an existing LCA on sugar beet production and processing since MOL and SBP are coproducts of the sugar industry . In conclusion, fermentation and the downstream are based on primary data, while the data used in the upstream (substrate supply, storage, and preparation) are secondary data.…”

“…The seed fermentation tanks include aeration modules, which were developed within the project Bio 2 . 49 In the following "fermentation" stage, in addition to the tank (operation volume 5000 L), a centrifuge (separation of solid and liquid phases) and pumps (e.g., substrate, water) are considered. Moreover, an aeration module is also included.…”

“…After seed fermentation, the produced inoculum for the main fermentation process is then pumped to the subsequent stage. The seed fermentation tanks include aeration modules, which were developed within the project Bio 2 …”

Novel multiphase loop reactor with improved aeration enables foam-free rhamnolipid production by Pseudomonas putida

“…The gas flow is controlled by two thermal mass flow controllers 5 connected via a 4-20 mA controller linked to the BioFlo110 control units. An online analytical device 6 measures oxygen and carbon dioxide concentrations in the exhaust gas. All equipment potentially contaminated by organisms is autoclavable.…”

“…All equipment potentially contaminated by organisms is autoclavable. 1 Eppendorf SE (Hamburg, Germany) 2 VisiFerm by Hamilton Company (Bonaduz, Switzerland) 3 phferm by Hamilton Company (Bonaduz, Switzerland) 4 Masterflex L/S Variable-Speed Drive by Cole-Parmer GmbH (Wertheim, Germany) 5 EL Flow Select F-201CV-20K-AGD-00-V by Bronkhorst Deutschland Nord GmbH (Kamen, Germany) 6 BlueVary, BlueSens GmbH (Herten, Germany) Fig. 3 Schematic illustration of the MPLR setup.…”