Bioreactor with addition tube

1. A bioreactor comprising:

a vessel defining an inner volume configured to contain liquid contents;

an agitation means;

at least one addition tube configured to introduce reagents from outside the bioreactor, the at least one addition tube having a first end protruding into the inner volume of the vessel to be in direct contact with the liquid contents of the vessel wherein cultivation takes place and a second end residing outside of the bioreactor, the second end being opposite to the first end and higher than the first end relative to a direction of gravity; and

a check valve having a delivery orifice adjacent the first end of the at least one addition tube, with the delivery orifice configured to be in direct contact with the liquid contents of the vessel wherein cultivation takes place, the check valve comprising an elastomeric closing member covering the delivery orifice, having an opening pressure below or equal to 10 kPa for allowing flow of a fluid in a downward direction along gravity from the second end, through the addition tube and through the delivery orifice into the inner volume of the vessel and blocking flow in the reverse direction,

wherein there is no or minimal stagnant zones outside the check valve,

wherein the check valve and the delivery orifice are arranged to be immersed in the liquid contents wherein cultivation takes place to fill the bioreactor, and

wherein the addition tube is telescopic such that the position of the delivery orifice in the vessel is adjustable.

2. The bioreactor of claim 1 , wherein the opening pressure of said check valve is between 10 Pa and 10 kPa.

3. The bioreactor of claim 1 , wherein the elastomeric closing member is selected from the group consisting of tubes, lips, flaps and split disks.

4. The bioreactor of claim 1 , wherein the vessel comprises a flexible plastic bag.

5. The bioreactor of claim 4 , wherein the flexible plastic bag is arranged to be supported by a rigid support structure during use.

6. The bioreactor of claim 1 , wherein the agitation means comprises an impeller.

7. The bioreactor of claim 4 , wherein the flexible plastic bag is inflatable and the agitation means comprises a movable support platform for the flexible plastic bag.

8. The bioreactor of claim 1 , wherein the addition tube is fluidically connected to a supply vessel containing a liquid solution comprising a pH regulator, a nutrient and/or a growth factor.

9. The bioreactor of claim 1 , wherein the opening pressure of said check valve is between 100 Pa and 10 kPa.

10. A bioreactor comprising,

a vessel defining an inner volume configured to contain liquid contents;

an agitation means;

at least one addition tube configured to introduce reagents from outside the bioreactor, the at least one addition tube having a first end protruding into the inner volume of the vessel to be in direct contact with the liquid contents of the vessel wherein cultivation takes place; and

a check valve having a delivery orifice adjacent the first end of the at least one addition tube, with the delivery orifice configured to be in direct contact with the liquid contents of the vessel wherein cultivation takes place, for allowing flow of a fluid in a downward direction along gravity from the addition tube into the inner volume through the delivery orifice and blocking flow in the reverse direction, such that there is no or minimal stagnant zones outside the check valve,

wherein the addition tube is telescopic such that the position of the delivery orifice in the vessel is adjustable, and

wherein the check valve and the delivery orifice are arranged to be immersed in the liquid contents wherein cultivation takes place to fill the bioreactor.

11. The bioreactor of claim 1 , wherein the at least one addition tube is further configured such that the first end protruding into the inner volume of the vessel is located near a bottom of the vessel.