Bioreactor Exhaust

• US 20110207170A1
• Filed: 05/01/2011
• Published: 08/25/2011
• Est. Priority Date: 05/01/2011
• Status: Active Grant

• Current Assignee: Adello Biologics, LLC
• Original Assignee: Therapeutic Proteins Inc.
• Inventors: Niazi, Sarfaraz K.
• Granted Patent: US 9,005,959 B2
• Time in Patent Office: Days
• US Class Current: 435/41
• CPC Class Codes: C12M 23/26 flexible flexible containers for laboratory use B01L3/505
• CPC Class Codes: C12M 23/28 disposable or single use
• CPC Class Codes: C12M 29/20 Degassing; Venting; Bubble traps means for collection or storage of gas C12M23/36; gas collection apparatus for laboratory use B01L5/02
• CPC Class Codes: C12M 41/40 of pressure
• CPC Class Codes: Y10T 137/0379 By fluid pressure
• CPC Class Codes: Y10T 137/6416 With heating or cooling of the system

Abstract

An exhaust system suitable for high volume exhaust from flexible disposable bags is described that prevents nutrient media volume loss and prevents cross-contamination without using any filters. The invention described here allows the use of disposable two-dimensional bioreactors for the cultivation of bacterial and other organisms and cells require high aeration.

Claims

1. A bioreactor exhaust assembly comprising:

(a) an exhaust tube with an inner volume and a lower end connected to a bioreactor and an upper end connected to a low pressure relief valve and a plurality of sensors including at least a pressure sensor and a temperature sensor;

(b) a means of cooling the exhaust tube to a temperature below the dew point of a gas in the exhaust tube;

(c) a means of keeping the exhaust tube upright.

2. The bioreactor exhaust assembly according to claim 1, wherein the exhaust tube is made from a polymer or a metal or a combination thereof.

3. The bioreactor exhaust assembly according to claim 1, wherein the exhaust tube is at least one-half inch in diameter.

4. The bioreactor exhaust assembly according to claim 1, wherein the exhaust tube has such length that the inside volume of the exhaust tube is 1% to 50% of a volume of gas exhausted per minute.

5. The bioreactor exhaust assembly according to claim 1, wherein the exhaust tube is flexible.

6. The bioreactor exhaust assembly according to claim 1, wherein the means of keeping the exhaust tube upright comprise attaching the exhaust tube to a vertical surface, holding it up by a hook at a higher elevation or winding it upward around a vertical cylindrical block with an outer surface.

7. The bioreactor exhaust assembly according to claim 6, wherein the vertical cylindrical block is made of a metal, preferably aluminum.

8. The bioreactor exhaust assembly according to claim 7, wherein the cylindrical block has a groove on the outer surface to completely seat the exhaust tube inside the groove.

9. The bioreactor exhaust assembly according to claim 7, wherein the cylindrical block further comprises a temperature sensor to measure the temperature of the cylindrical block.

10. The bioreactor exhaust assembly according to claim 1, wherein the means of cooling the exhaust tube comprise blowing cold air over it, enclosing it in a cold box, by submerging it in a cold liquid.

11. The bioreactor exhaust assembly according to claim 7, wherein the means of cooling the cylindrical block comprise circulating a cold liquid in the cylindrical block.

12. The bioreactor exhaust assembly according to claim 1, wherein the low pressure relief valve is a mechanical or electro-mechanical device.

13. The bioreactor exhaust assembly according to claim 1, wherein the low pressure relief valve provides an instant hermetic seal when closed.

14. The bioreactor exhaust assembly according to claim 1, wherein the pressure sensor is electronically or mechanically connected to the low pressure relief valve to open or close the low pressure relief valve automatically according to conditions programmed in the pressure sensor.

15. The bioreactor exhaust assembly according to claim 1, wherein the low pressure relief valve opens when the pressure in the exhaust tube reaches above a pressure of 0.05-inch (±

10%) water gauge and closes when the pressure in the exhaust tube reaches below a pressure of 0.05-inch (±

10%) water gauge in the exhaust tube.

16. The bioreactor exhaust assembly according to claim 1, wherein the bioreactor exhaust assembly is connected to a two-dimensional soft wall container, a three-dimensional soft-wall container or a three-dimensional hard-walled container.

17. A method of ventilating a bioreactor comprising:

(a) providing a bioreactor exhaust assembly according to claims 1-16;

(b) winding and seating completely the exhaust tube in the groove in the vertical cylindrical block;

(c) attaching the top end of the exhaust tube to the condenser block;

(d) cooling down the cylindrical block to a temperature between 5°

C. and 8°

C. by turning on and recirculating the cooling liquid in the cylindrical block;

(e) attaching the lower end of the exhaust tube to a gas outlet in the bioreactor;

(f) letting the exhaust from the bioreactor enter the exhaust tube;

(g) letting the condensate form in the exhaust tube;

(h) letting the condensate in the exhaust tube flow back in the bioreactor;

(i) measuring the pressure inside the exhaust tube using the pressure sensor attached to the condenser box;

(j) releasing the exhaust gas to atmosphere by opening the low pressure relief valve when the pressure in the exhaust tube reaches a pressure above 0.05-inch (±

10%) water gauge;

(k) closing the low pressure relief valve and stopping the exhaust of gas to atmosphere when the pressure inside the condenser box reaches below 0.05-inch (±

10%) water gauge;

(l) repeating steps (i)-(k) till the end of the bioreaction cycle

38. A method of manufacturing a biological product comprising:

(a) providing a bioreactor exhaust assembly according to claim 1-16 or 18-36;

(b) providing a two dimensional flexible bioreactor bag comprising;

(i) a gas inlet with a top end and a bottom end and an inner volume;

(ii) a sterilizer filter attached to the top end of the gas inlet;

(iii) a sparging filter attached to the bottom end of the gas inlet and disposed in the bioreactor bag;

(iv) a gas outlet;

(v) a nutrient media inlet/outlet;

(vi) a plurality of sensors with at least a temperature sensor;

(c) a bioreactor bag operational platform comprising;

(i) a flat metal plate with a top surface and a bottom surface;

(ii) a vertical support for the flat metal plate with adjustable legs to change the inclination of the flat metal plate;

(iii) a resistance heater attached to the bottom surface of the flat metal plate;

(iv) a flapper attached to one end of the flat metal plate and capable of moving between 10 to 90 degrees;

(d) turning on the resistance heater of the bioreactor operational platform;

(d) placing a bioreactor bag on the top surface of the flat metal plate;

(e) introducing a pre-determined volume of nutrient media inside the bioreactor bag through the media inlet;

(f) allowing sufficient time for the nutrient media to reach a pre-determined temperature;

(g) connecting the gas outlet of the bioreactor assembly to the bioreactor exhaust assembly according to claim 1-16 or 18-36 and operating the bioreactor exhaust assembly;

(h) adding a biological culture to the bioreactor bag through the nutrient media inlet;

(i) turning on the flapper to move it periodically between 90 degree and 10 degree to push against the bioreactor bag to create a wave motion inside the bioreactor bag;

(j) raising one end of the metal plate to a pre-determined angle by adjusting the height of the legs of the vertical support;

(k) start passing gas through the gas inlet and through the sterilizing filter and the sparger rod;

(l) letting the exhaust from the bioreactor bag to enter the bioreactor exhaust assembly and operating the bioreactor exhaust assembly until the end of the bioreaction cycle;

(m) removing the nutrient media and biological culture from the bag at the end of bioreaction cycle and separating the cell mas and treating it further to purify the biological product.

18. A bioreactor exhaust assembly comprising:

(a) an exhaust tube with an inner volume and a lower end connected to a bioreactor and an upper end connected to a condenser box;

(b) a means of cooling the exhaust tube to a temperature below the dew point of a gas in the exhaust tube;

(c) a means of keeping the exhaust tube upright;

(d) a plurality of sensors with at least a pressure sensor and a temperature sensor;

(e) a condenser box with a top and a bottom and an inner volume, a connector to the exhaust tube, a condenser coil, an inlet for cold liquid to cool the condenser coil, an outlet for recirculating the cold liquid in the condenser coil, a pressure sensor, a low pressure relief valve, an exhaust outlet, a plurality of sensors with at least a pressure sensor and a temperature sensor, a bottom drain and a stopcock to operate the drain.

19. The bioreactor exhaust assembly according to claim 18, wherein the exhausts tube is made from a polymer or a metal material or a combination thereof.

20. The bioreactor exhaust assembly according to claim 18, wherein the exhaust tube is at least one-half inch in diameter.

21. The bioreactor exhaust assembly according to claim 18, wherein the exhaust tube is flexible.

22. The bioreactor exhaust assembly according to claim 18, wherein the exhaust tube has such length that the inside volume of the exhaust tube is 1% to 50% of a volume of gas exhausted from the bioreactor per minute.

23. The bioreactor exhaust assembly according to claim 18, wherein the means of keeping the exhaust tube upright comprise attaching the exhaust tube to a vertical surface, holding it up by a hook at a higher elevation or winding it upward around a vertical cylindrical block.

24. The bioreactor exhaust assembly according to claim 23, wherein the vertical cylindrical block is made of a metal, preferably aluminum and has an outer surface.

25. The bioreactor exhaust assembly according to claim 24, wherein the cylindrical block has a groove on the outer surface of the cylinder block to completely seat the exhaust tube inside the groove.

26. The bioreactor exhaust assembly according to claim 24, wherein the cylindrical block further comprises a temperature sensor to measure the temperature of the cylindrical block.

27. The bioreactor exhaust assembly according to claim 18, wherein the means of cooling the exhaust tube comprise blowing cold air over it, enclosing it in a cold box, or by submerging it in a cold liquid.

28. The bioreactor exhaust assembly according to claim 24, wherein the means of cooling the exhaust tube comprise circulating a cold liquid in the cylindrical block.

29. The bioreactor exhaust assembly according to claim 18, wherein the condenser box is kept at a lower height than the upper end of the exhaust tube.

30. The bioreactor exhaust assembly according to claim 18, wherein the condenser coil in the condenser box is kept at a temperature between 5°

C. and 8°

C. by circulating a cold liquid through the condenser coil.

31. The bioreactor exhaust assembly according to claim 18, wherein the condenser box further comprises a plurality of sensors including at least a temperature sensor to measure the temperature inside the condenser box.

32. The bioreactor exhaust assembly according to claim 18, wherein the low pressure relief valve is a mechanical or electro-mechanical device.

33. The bioreactor exhaust assembly according to claim 18, wherein the low pressure relief valve provides an instant hermetic seal when closed.

34. The bioreactor exhaust assembly according to claim 18, wherein the pressure sensor is electronically or mechanically connected to the low pressure relief valve to open or close the low pressure relief valve automatically according to conditions programmed in the pressure sensor.

35. The bioreactor exhaust assembly according to claim 18, wherein the low pressure relief valve opens when the pressure in the condenser box reaches above 0.05-inch (±

10%) water gauge and closes when the pressure in the condenser box reaches below a pressure of 0.05-inch (±

10%) water gauge in the condenser box.

36. The bioreactor exhaust assembly according to claim 18, wherein the bioreactor exhaust assembly is connected to a two-dimensional soft wall container, a three-dimensional soft-wall container or a three-dimensional hard-walled container.

37. A method of ventilating a bioreactor comprising:

(a) providing a bioreactor exhaust assembly according to claims 18-36;

(b) winding and seating the exhaust tube in the groove in the vertical cylindrical block;

(c) attaching the top end of the exhaust tube to the condenser block;

(d) cooling down the cylindrical block to a temperature between 5°

C. and 8°

C. by turning on and recirculating the cooling liquid in the cylindrical block;

(d) cooling down the condenser box to a temperature between 5°

C. and 8°

C. by turning on and recirculating the cooling liquid through the condenser coil;

(e) attaching the lower end of the exhaust tube to a gas outlet in the bioreactor;

(f) letting the exhaust gas from the bioreactor enter the exhaust tube;

(g) letting the first condensate formed in the exhaust tube;

(h) letting the first condensate to flow back in the bioreactor;

(j) letting the second condensate form in the condenser;

(k) letting the second condensate collect at the bottom of the condenser box;

(l) measuring the pressure inside the condenser box using the pressure sensor in the condenser box;

(m) releasing the exhaust gas to atmosphere by opening the low pressure relief valve when the pressure in the condenser reaches a pressure above 0.05-inch (±

10%) water gauge;

(n) closing the low pressure relief valve and stopping the exhaust of gas to atmosphere when the pressure inside the condenser box reaches below 0.05-inch (±

10%) water gauge;

(o) draining the second condensate when it reaches a certain maximum level by opening the stopcock of the drain tube attached to the bottom of the condenser box;

(p) repeating steps (l)-(o) till the end of the bioreaction cycle.