EP3740557A1

EP3740557A1 - Electric bioreactor and parts thereof for sterile microbial electrosyntheses for multiple and single use

Info

Publication number: EP3740557A1
Application number: EP18701701.7A
Authority: EP
Inventors: Steffi Hunger; Falk Harnisch; Carla Gimkiewicz; Vitalij JEGOROW; Luis Filipe Morgado Rosa; Beate Strehlitz
Original assignee: Helmholtz Zentrum fuer Umweltforschung GmbH UFZ
Current assignee: Helmholtz Zentrum fuer Umweltforschung GmbH UFZ
Priority date: 2018-01-18
Filing date: 2018-01-18
Publication date: 2020-11-25
Also published as: WO2019141365A1

Abstract

The aim of the invention is to provide an electric bioreactor (10) for carrying out a sterile microbial electrosynthesis and/or parts thereof. This aim is achieved, according to the invention, by an insert (15) having a through opening (24) provided through a membrane (25) and an electric bioreactor (10), which has a bioreactor vessel (12) open to one side and the insert (15) which can be introduced reversibly into the bioreactor vessel (12). A first reaction chamber (27) and, between the insert (15) and the inner wall of the bioreactor vessel (12), a second reaction chamber (28) are formed in the insert (15), and the bioreactor vessel (12) and the insert (15) are suitable to be sterilised. The invention further relates to a kit comprising an electric bioreactor and/or parts thereof and to uses of the insert and of the electric bioreactor (10).

Description

Electrobioreactor and its parts for sterile microbial electrosynthesis for reusable and

One-time use

The present invention relates to an insert for a bioreactor vessel for forming an electrobioreactor for performing a sterile microbial electrosynthesis, an electrobioreactor with the aforementioned use, a kit comprising an electrobioreactor or its parts, a use of the aforementioned insert and the electro bioreactor.

Bioelectrosynthesis or electrobiosynthesis is divided into enzymatic electrosynthesis and microbial electrosynthesis. The aim of microbial electrosynthesis is the linking of microbial synthesis power with the flow of electrical current. In this case, both electrical current can be converted in the case of oxidation processes to anodes and also in the case of reductions at the cathode, and thus can be used as reactant. In both cases, microbial conversion is associated with the flow of electrical current. The coupling is preferably carried out directly via extracellular electron transfer or indirectly via an abiotic electrochemical reaction for substrate or product conversion of microbial syntheses.

The extracellular electron transfer (EET) can be mediated by direct electrode contact (direct EET = DEET) or by soluble molecules (mediated EET = MEET). The DEET can take place by means of membrane-bound redox molecules or via pili, which act like nanowires (nanowires). The MEET may be via natural (endogenous) or process-added (exogenous) mediators. Furthermore, microorganisms which are of course capable of EET or have been developed microbiologically or molecularly for it can be used.

The microbial electrosynthesis in comparison to classical electrochemical synthesis has numerous advantages such as potentially higher selectivities, yields, etc., but there are also advantages over enzymatic electrosyntheses, since in most cases only max. Two electrons can be transferred per reaction step and the catalyst is not self-regenerating, but this may be the case in microbial electrosynthesis. In sterile microbial electrosynthesis, the following processes may be included:

i) Electrobiotechnological investigations, control and use

of microbial pure cultures,

ii) Specific bioelectrochemical control of the cultivation of

Microorganisms and product formation with microorganisms, incl. The electrochemical fermentation control and

iii) Specific Electrochemical Substrate and / or Product Conversion

during the cultivation of microorganisms

Reactors which are suitable for carrying out the microbial electrosynthesis are disclosed, for example, in the publications US 2013/0256149 A1, WO 201 1/062485 A2, WO 2010/117864 A1 and WO 00/03447 DE 10 2013 224 673 A1.

In many branches of the biotechnology industry, sterilizable bioreactors and sterile disposable bioreactors, i. E. Reactors that are delivered in a sterile package and ready for immediate use are the drug of choice for research and development as well as for production. Sterile bioreactors are well established for numerous applications in slightly different designs, for example with regard to the geometry of the bioreactor vessel.

It is an object of the invention to provide an electrobioreactor for performing a sterile microbial electrosynthesis or its parts.

This object is achieved by an insert for a bioreactor vessel, an electrobioreactor, a kit for forming an electrobioreactor and uses of the insert and the electrobioreactor having the features of the independent claims. Advantageous embodiments of the invention are the subject of the dependent claims.

According to the invention, an insert for a bioreactor vessel for forming an electrobioreactor for carrying out a sterile microbial electrosynthesis is provided. This insert has a top, a bottom and a wall between the top and bottom running on. The top of the insert is designed open and the wall is provided with at least one passage opening. The at least one passage opening is closed by a preferably ion-selective membrane. In addition, the insert according to the invention is suitable to be sterilized.

In the context of this application, the term bioreactor is used if it is not equipped for microbial electrobiosynthesis. If the insert according to the invention is introduced into the bioreactor, this electrobioreactor is called.

This insert, as will be described below, can be introduced into a bioreactor or into the bioreactor vessel of a bioreactor in order to subdivide the reaction chamber into two reaction chambers connected through the membrane and thus to provide an electrobioreactor with separation of anode chamber and cathode chamber.

Since microbial electrobiosyntheses are preferably carried out under sterile conditions, the insert according to the invention can be sterilized, i. H. The insert consists of sterilizable materials such as glass, ceramics or plastics, preferably plastics.

The sterilization can either be done by a user himself or the insert can be sterilized in a sterile package purchased, the use is suitable for re-sterilization or single use.

The membrane is an ion-conducting, preferably an ion-selective membrane. The membrane is preferably an ion exchange membrane, preferably based on functionalized and cross-linked hydrocarbons. For example, a Nafion membrane or a ceramic membrane can be used.

Composite materials of ion exchange membranes and other plastics such as polyesters, polypropylenes and polyetheretherketone, (functionalized) ceramic materials and materials based on (functionalized) glasses and composite materials thereof can also be used according to the invention.

The membrane is preferably formed by casting, welding (eg gas welding, extrusion welding, heating element welding, RF welding, ultrasonic welding), gluing with adhesives based on acrylics, epoxies and the like or mechanical joining technologies (screwing, pressing, "snap") in the through hole of the For use with glass or ceramic inserts the membrane is already introduced or etched into the material directly during production. Crucial in the production process is that the resulting use is sterilizable.

The material selection for the insert and its embodiments will be described otherwise below in connection with the electro bioreactor according to the invention.

The size and the number of at least one passage opening and thus the membrane (s) is chosen such that the internal resistance is minimized. Therefore, the ratio of the size of the electrodes used for the synthesis, which are respectively arranged in the two reaction chambers of the electrobioreactor, to the size and the number of the passage opening or the membrane (s) is expediently in the range from 1: 100 to 100: 1.

In addition, depending on the type of connection between the membrane (s) and the insert, the through hole (s) may consist of one or more small through holes with round or polygonal shapes which may be evenly or irregularly distributed around the circumference of the insert.

In a preferred variant, the insert is cylindrically shaped, since this allows an optimal mixing of the media in the reaction chambers in the electrobioreactor.

Particularly preferably, the insert has a cover with which the opening of the insert or the open top can be closed. The cover has at least one passage opening, which is preferably suitable and configured for receiving an electrode and a reference electrode. Other ports may be provided for various purposes, as described below.

The guided during use of the insert through the through hole electrode protrudes into the insert into it. Other devices guided by the lid, such as a reference electrode, protrude into the reaction chamber formed by the insert. In the simplest case, the passage opening is guided through the lid like a through-hole. However, it can also be provided a shoulder in the through hole, which can serve as a support for a corresponding counterpart of an electrode.

In addition, at least one sealing element, for example an annular seal, can be provided in the at least one passage opening on or in the passage opening for the electrode in order to prevent influences from outside the electrobioreactor during the synthesis and to better ensure the sterility for the microbial bioelectrosynthesis.

In the region of the upper side of the insert, a flange is preferably provided, on which the lid rests, it being possible for a seal to be arranged between the lid and the insert.

According to a particularly preferred embodiment of the insert, this is combined with a cover for a bioreactor or a bioreactor vessel. Thus, the insert may be arranged in a passage opening of the lid, wherein the insert and the lid are separate components or may be integrally formed. When closing the electro bioreactor with the lid, the insert projects into the electro bioreactor.

Preferably, means are provided to fix the insert in the passage opening of the cover for the Bioreaktorgefäß.

Between the cover for the bioreactor vessel and the lid of the insert, a sealing element, for example an annular seal, is preferably provided.

According to a preferred embodiment, the cover for the electrobioreactor is formed integrally with the insert.

As already stated, the insert according to the invention can be made up as a sterile (once) product, which can also be used several times after renewed sterilization.

Preferably, therefore, the insert according to the invention in the above-described embodiments can be arranged sterile in a sterile packaging on the inside. According to an embodiment of the invention, the insert can also be designed to be open on the underside, wherein it must then be dimensioned in such a way that it rests on the bottom of the bioreactor vessel and is preferably sealed and fixed by suitable means.

Otherwise, the insert is preferably designed to be closed on the bottom side and, after introduction into the bioreactor vessel, is spaced from its bottom in order to receive suitable stirring means, such as magnetic stirrers, in the intermediate space.

According to the invention, an electrobioreactor for carrying out a sterile microbial electrosynthesis is also provided, which has a bioreactor vessel open to one side (upper side) which has a previously described insert with lid and optionally a lid for closing the opening of the bioreactor vessel.

The insert is reversibly insertable into the bioreactor vessel and open to the same side as the bioreactor vessel, the insert being spaced from the interior wall of the bioreactor vessel, thereby forming a reaction chamber between the insert and the wall of the bioreactor vessel. Another reaction chamber is in use. The bioreactor vessel is also suitable to be sterilized.

Furthermore, the insert has in the wall facing the inner wall of the reactor vessel a through-opening closed with a membrane, wherein the bioreactor vessel, the lid of the bioreactor vessel, the insert and / or the lid of the insert are suitable for being sterilized. Furthermore, reference is made to the above statements on the use.

Above in relation to the electrobioreactor is here defined as a standing surface of the insert or a Bioreaktorgefäßes in which the insert is arranged, opposite.

All internals of the electrobioreactor which come into contact with reactants should preferably be designed sterilizable. The electrobioreactor and at least one, preferably all of the parts described above are made of an electrochemically inert material, which is also preferably autoclavable / steam sterilizable.

In the case of disposable use, in particular of the insert and of the lid or lids, it is advantageously possible to use cheaper plastics (for example polylactic acid) which are not autoclavable but gamma-sterilizable.

Autoclavable plastics, glass, or ceramics are used for the reusable parts of the insert. Corresponding plastics are known to the person skilled in the art.

As already stated, the cover of the bioreactor vessel and the lid of the insert for connecting the anode and cathode have suitable through openings, preferably with corresponding seals, wherein the through openings are configured to receive the electrodes in such a way that the anode / cathode is located in the insert, and the cathode / anode is located outside the insert in the bioreactor vessel.

Further passages or passage openings in the lid of the bioreactor vessel may be provided for introducing stirrers, probes, electrodes, reference electrodes, measuring probes, gassing or degassing, sampling and the like, wherein the passages or passage openings may be provided with seals.

All passage openings are within the scope of the invention, if they are not used, with a suitable means such as a plug or the like. closed, otherwise no sterile operation is possible.

The lid for the bioreactor vessel preferably has conventional attachment means and seals. For attachment, the bioreactor vessel at the top can also have a flange on which the lid rests and can be fixed by means known to those skilled in the art. Between the flange and the lid can also be arranged a seal.

It is particularly preferred to use the electrobioreactor or the bioreactor vessel and / or the lid of the bioreactor vessel and / or the insert and / or the lid of the insert sterile and in each case or together to arrange in a sterile on the inside packaging.

The invention furthermore relates to a kit for a previously described electrobioreactor, or a previously described bioreactor vessel and also an insert described above, optionally comprising a lid for the bioreactor vessel and / or a lid for use, wherein the components of the kit are sterile and sterile individually or together are packed.

Also claimed in accordance with the invention are the use of the bioreactor vessel, bioreactor vessel, electrobioreactor to perform sterile microbial electrosynthesis, and use of the resulting electrobioreactor to perform sterile microbial electrosynthesis.

The volume of the two reaction chambers of the electrobioreactor according to the invention is particularly preferably in the ratio 1: 1, but also ratios of 10: 1 to 1:10 are preferably used to carry out a sterile microbial electrosynthesis.

When carrying out syntheses with the electro bioreactor according to the invention, the electrodes used are anodes and cathodes as well as reference electrodes. In this case, the anode or cathode is in the outer reaction chamber of the electro bioreactor and the respective other electrode in the inner reaction chamber, ie in use. Both electrodes can each have a plurality of interconnected electronic conductors (electrodes), connected in parallel or in series; include. Electrodes may have the same or different geometries and sizes and be made of the same or different materials. Suitable materials are metals and nonmetals. Suitable non-metals may be, for example, graphite and graphite modifications, eg carbon nanotubes or carbon nanoparticles, as well as all corresponding composite materials. The metals used are, for example, gold, silver, zinc, gallium, copper, nickel, iron, platinum, titanium, etc., and their bi-, trinary and higher alloys. Furthermore, this includes electrode materials based on a functional surface coating of said materials on a substrate, including conductive substrates such as stainless steels or graphites. The electrode specification may comprise all geometric shapes and modifications of said metals and nonmetals, in particular sheets, plates, films, rounds, tubes, sponges, scrims, fabrics, brushes, cylinders.

The reference electrode is preferably located in the outer electrobioreactor chamber, but may also be arranged in the inner chamber or in both chambers. As reference electrodes known in the art products are used.

The microbial electrosynthesis preferably takes place at direct current.

All of the above-described objects and uses of the invention and embodiments thereof are to be advantageously combined. Furthermore, the statements concerning certain objects and uses of the invention and their embodiments always also relate to the other objects and uses of the invention and their embodiments.

The invention will be explained in more detail with reference to drawings. Show it

Figure 1 is a schematic representation of a microbial electrosynthesis on

Example of Cathodic Hydrogenation Utilizing Microbial Extracellular Electron Transfer in the Prior Art;

FIG. 2 shows a perspective view of an electrobioreactor according to the invention with an insert for a bioreactor vessel

FIG. 1 shows by way of example a microbial electrosynthesis according to the prior art. It is a cathodic hydrogenation using microbial extracellular electron transfer. In two mutually separated by a membrane 1 10 reaction chambers 11 1, 112 each have an anode 113 and a cathode 1 14 is arranged, which are connected to a voltage source 115, wherein the cathode 114 is provided with a biofilm 116 of a bioelectrocactively active microorganism. At the cathode 1 14, a substrate X is selectively reduced by taking up electrons from the cathode to the product XH ₂ , while at the anode 1 13 H ₂ 0 to provide H ⁺ and electrons is oxidized, with electrons being delivered to the anode. Through the membrane 1 10, the corresponding ion transfer 117 takes place. The resulting product XH ₂ is removed from the reaction chamber 1 12, while substrate X is fed.

For biotechnologically interesting concepts, especially the chemo-, regio-, and stereospecificity of microbial bioelectrosynthesis is of great value. In this case, the reaction substrate or the biofilm is not used as a growth substrate for the biofilm, but a separate growth substrate provides stable stationary properties of the biofilm. Similarly, anodic concepts, i. for microbial electro-oxidation.

FIG. 2 shows an electrobioreactor 10 according to the invention for carrying out a sterile microbial electrosynthesis. The electrobioreactor 10 has a cylindrical bioreactor vessel 12 open to one side 11 (usually upwards, ie against gravity), a lid 13 for closing the opening 14 of the bioreactor vessel 12 and an insert 15 reversibly insertable into the bioreactor vessel 12 ,

In the illustrated embodiment of the electrobioreactor 10, the insert 15 is cylindrically shaped like the bioreactor vessel 12, but has a smaller diameter. The insert 15 is likewise designed to be open on the upper side 16 and can be attached via a flange 17 into a passage opening 18 with formations corresponding to the flange 17, not shown here, of the lid 13 of the electrobioreactor 10 and thus introduced into the bioreactor vessel 12.

The insert 15 is closed by a cover 19, which has two passage openings 20, wherein an electrode 21 is arranged in at least one passage opening 20. In the other passage opening 20, a second electrode can be arranged depending on the required electrode area. In addition, the lid 19 has four openings 22 for the passage of fasteners, such as screws or the like, with which a fixation on the lid 13 of the electro bioreactor 10 takes place. The fastening means are not shown here. Between the flange 17 of the insert 15 and the lid 19 of the insert 15 not shown seals can be arranged. The insert 15 has in the wall 23 three superimposed arranged through openings 24, which are each closed by a membrane 25.

The lid 13 for closing the opening 14 of the bioreactor vessel 12 is formed such that a flange 26 provided on the bioreactor vessel 12 formed at the opening 14 is gripped and sealed so that the lid 13 is fixed in its fitted state , Again, not shown seals and fasteners may be provided.

In the assembled state of the electrobioreactor 10, two reaction chambers 27, 28 are formed in the bioreactor vessel 12. A first reaction chamber 27 is formed through the interior of the insert 15 and the second reaction chamber 28 through the space between the insert 15 and the inner wall of the bioreactor vessel 12. Both reaction chambers 27, 28 are interconnected by the membrane (s) 25. For mixing, there are two magnetic stirrers 29 in the bioreactor vessel 12, wherein the insert 15 is spaced on the bottom side from the bioreactor vessel 12 so that the magnetic stirrers 29 can be arranged in the given interspace. In addition, if required, a magnetic stirrer, not shown here, can also be located in the insert 15.

In the lid 13 of the Bioreaktorgefäßes 12 also has a through hole 30 is provided, through which an electrode 31 is guided. In a further passage opening 32, a reference electrode 33 is arranged. The electrode 31 and the reference electrode 33 are in the assembled state of the electrobioreactor 10 in the second reaction chamber 28. In addition, a plurality of additional through holes 34 are provided in the lid 13, in the electrodes, probes, gassing or degassing, sampling or the like, not shown can be introduced. All through holes 20, 30, 32, 34 are, if they are not used with a suitable means such as a plug or the like. closed, otherwise no sterile operation is possible. LIST OF REFERENCE NUMBERS

Membrane 110

Reaction chamber 111,112

Anode 113

Cathode 114

Voltage source 115

Biofilm 116 ion transfer 117

Substrate X

Product XH ₂

Electrobioreactor 10

Page 11

Bioreactor vessel 12

Cover 13

Opening 14

Use 15

Top 16

Flange 17

Through opening 18

Lid 19

Through opening 20

Electrode 21

Opening 22

Wall 23

Through hole 24

Membrane 25.

Flange 26

Reaction chambers 27, 28

Magnetic stirrer 29

Through hole 30

Electrode 31 Through opening 32

Reference electrode 33

Through hole 34

Claims

claims

An insert (15) for a bioreactor vessel (12) for forming an electrobioreactor (10) for performing a sterile microbial electrosynthesis, with an upper side (16), a lower side and a wall (23) extending between the upper side (16) and lower side, wherein the top (16) is open, wherein the wall (23) has at least one through hole (24) provided with a membrane (25), and wherein the insert (15) is adapted to be sterilized.

2. insert (15) according to claim 1, characterized in that the insert (15) has a cover (19) for closing the open top (16), wherein the lid (19) has at least one passage opening (20) and at least a through hole (20) is configured to receive an electrode (21) such that the electrode (21) is located in the insert (15). 3. insert (15) according to claim 1 or 2, characterized in that the

Insert (15) is provided with a lid (13) for the Bioreaktorgefäß (12) or is integrated therein, wherein the insert (15) in a through hole (18) of the lid (13) is arranged. 4. insert (15) according to one of claims 1 to 3, characterized in that the at least one passage opening (24) with a membrane (25), preferably an ion-selective membrane (25) is provided.

5. insert (15) according to one of claims 1 to 4, characterized in that the insert (15) consists of an electrochemically inert material.

6. insert (15) according to one of claims 1 to 5, characterized in that the insert (15) and / or the lid (19) and / or the lid (13) for the Bioreaktorgefäß (12) is autoclavable / steam sterilized or are. 7. insert (15) according to any one of claims 1 to 6, wherein the insert (15) and / or the lid (19) and / or the lid (13) for the Bioreaktorgefäß (12) is or are sterile and each or together is arranged in a on the inside sterile packaging or are. 8. Electrobioreactor (10) to perform a sterile microbial

An electrosynthesis comprising a bioreactor vessel (12) open to one side, optionally a lid (13) for closing the opening (14) of the bioreactor vessel (12), and an insert (15) according to any one of claims 1 to 7 inserted in the bioreactor vessel (12) is reversibly insertable and is open to the same side as the Bioreaktorgefäß (12), wherein in the insert (15) has a first

Reaction chamber (27) is formed and the insert (15) from the inner wall of Bioreaktorgefäßes (12) is spaced, whereby a second reaction chamber (28) is formed, and in the inner wall of Bioreaktorgefäßes (12) facing wall (23) at least one provided with a membrane (25) through opening (24) is provided, wherein the

Bioreactor vessel (12), the lid (13) and the insert (15) are suitable to be sterilized.

9. electro bioreactor (10) according to claim 8, characterized in that the cover (13) of the Bioreaktorgefäßes (12) at least one passage opening

(30), wherein a through hole (30) is configured to receive an electrode (31) such that the electrode (31) is located outside of the insert (15) in the bioreactor vessel (12). 10. electro bioreactor (10) according to claim 8 or 9, characterized in that the Bioreaktorgefäß (12) and optionally the lid (13) are autoclavable or steam sterilized.

11. Electrobioreactor (10) according to any one of claims 8 to 10, characterized in that the electro bioreactor (10) consists at least partially of an electrochemically inert material.

12. Electrobioreactor (10) according to any one of claims 8 to 11, wherein the electrobioreactor (10) and / or the insert (15) and / or the lid (13) is sterile and are sterile and each or together in one on the inside Packaging is arranged or are.

A kit comprising an electrobioreactor (10) according to any one of claims 8 to 12, or a bioreactor vessel (12) and / or insert (15) according to any one of claims 1 to 7, and / or a lid (13) for the bioreactor vessel (12) and / or a lid (19) for the insert (15), wherein the components of the kit are sterile and are packaged individually or together sterile.

14. Use of an insert (15) according to any one of claims 1 to 7 for the equipment of a bioreactor for generating an electro bioreactor (10) in order to perform a sterile microbial electrosynthesis with this.

15. Use of an electrobioreactor (10) according to any one of claims 8 to 12 for carrying out a sterile microbial electrosynthesis.