Characterization of a membrane‐separated and a membrane‐less electrobioreactor for bioelectrochemical syntheses

Abstract

Bioelectrochemical systems (BESs) have the potential to contribute to the energy revolution driven by the new bio-economy. Until recently, simple reactor designs with minimal process analytics have been used. In recent years, assemblies to host electrodes in bioreactors have been developed resulting in so-called "electrobioreactors." Bioreactors are scalable, well-mixed, controlled, and therefore widely used in biotechnology and adding an electrode extends the possibilities to investigate bioelectrochemical production processes in a standard system. In this work, two assemblies enabling a separated and non-separated electrochemical operation, respectively, are designed and extensively characterized. Electrochemical losses over the electrolyte and the membrane were comparable to H-cells, the bioelectrochemical standard reaction system. An effect of the electrochemical measurements on pH measurements was observed if the potential is outside the range of -1,000 to +600 mV versus Ag/AgCl. Electrobiotechnological characterization of the two assemblies was done using Shewanella oneidensis as an electroactive model organism. Current production over time was improved by a separation of anodic and cathodic chamber by a Nafion® membrane. The developed electrobioreactor was used for a scale-up of the anaerobic bioelectrochemical production of organic acids and lysine from glucose using an engineered Corynebacterium glutamicum. Comparison to a small-scale custom-made electrobioreactor indicates that anodic electro-fermentation of lysine and organic acids might not be limited by the BES setup but by the biocatalysis of the cells.

Same but different–Scale up and numbering up in electrobiotechnology and photobiotechnology

“…This has been shown for the production of para‐hydroxybenzoate in a single chamber reactor with up to 2.5 L working volume , for current production in a single chamber system with 2.5 L , for current production in a two chamber electro‐stirred tank reactor with up to two liter and for the production of organic acids in a two chamber reactor with up to 2 l . It has also been shown that CFD (Computational Fluid Dynamics) studies for the “upgraded” bioreactors reveal the mixing conditions within the reactor, so it might be possible to use the knowledge gained from CFD simulations for the scale up of the systems . Recently, developed a single‐chamber BES with a rode‐shaped “All‐in‐One” electrolysis electrode which can be easily inserted into typical bioreactors (e.g.…”

“…On the contrary, it is necessary to also maintain the flow regime within the cell, giving reason for the use of rational scale up methods . Rational scale up in electrobiotechnology to a larger scale has not been shown so far, but several suggestions for scale up parameters have been made, including the calculation of dimensionless numbers, geometrical similarity, model‐based approaches such as computational fluid dynamics and electrode surface area .…”

Current to Clean Water – Electrochemical Solutions for Groundwater, Water, and Wastewater Treatment

“…Microbial fuel cells are still in the spotlight of academic research; however, a rising number of publications is dealing with the industrial implementation such as scale‐up approaches of electrochemical bioreactors or the implementation of MFCs into WWTPs , . It can be stated, that MFCs are an emerging and economical technology that combines wastewater treatment and current generation.…”

Microbial electrosynthesis: anode- and cathode-driven bioproduction of chemicals and biofuels

“…add electrochemical control to the system while at the same time being able to use the existing infrastructure of the commercial bioreactor allowing a define controlled fermentation process (Figure 11). 154 The assembly was made of PEEK and designed and manufactured to host the working and Identical fittings were used to contact the working and counter electrode by integration of a glass cylinder (d=6 mm) with a platinum wire (d=0.5 mm, manufactured from Fischer Labortechnik GmbH, Frankfurt am Main, Germany) melted into the glass cylinder. The scaled-up reactor was operated and inoculated in the same manner as described above in the experiments using 350 mL custom-made electrobioreactors.…”

“…Sulfuric acid (5 mM) was used as mobile phase with a flow rate of 0.6 mL min -1 at 60 °C over a total run time of 30 min. Quantification was done using a calibration curve with external standards in the range of 0 to 200 mM lactate, succinate and acetate, respectively 154. Lysine and alanine were analyzed on an equivalent HPLC system equipped with a Kinetex® 2.6 µm XB-C18 100 Å 30x2.1 mm column (Phenomenex, Aschaffenburg, Germany) and coupled to a triplequadrupole mass spectrometer (LCMS-8040, Shimadzu Deutschland GmbH, Duisburg, Germany) with an electrospray ionization source (Shimadzu Deutschland GmbH, Duisburg, Germany).…”