摘要:
A cell culture reactor can have one or more gasification modules in which tubular membrane hoses surround rigid inner tubes which extend above the membranes to communicate with gas inlets or outlets. The tube is anchored in a closure member at the lower end of the membrane.
摘要:
Stem cells or other organ-function cells are cultivated in a fluidized bed system on macroporous glass carrier bodies treated with a structure protein such as gelatin and an extracellular matrix protein such as fibronectin, and coated with a stroma cell layer. Glass carriers coated with gelatin are added to a fluidized bed reactor, and a culture medium containing an extracellular matrix protein is added to bind the protein to the gelatin. Stromal cells are then added and the cells are cultured to immobilize the cells on the carriers containing the bound protein. Immature organ-function cells are added to the reactor, and while generating a fluidized bed of the carriers in the culture medium, the culture medium is recirculated from and to the reactor in a recirculation loop. Bubble-free aeration of the culture medium is effected to cultivate the immature organ-function cells on the carriers to obtain both mature differentiated organ-function cells and progenitor organ-function cells. Mature differentiated organ-function cells which are released from the carriers are harvested from the reactor while retaining the progenitor organ-function cells which adhere to the carriers to provide an equilibrium between the harvested mature differentiated organ-function cells, the progenitor cells and the immature cells added to the reactor. Growth and regulatory factors for cultivating organ-function cells can be produced by culturing immobilized stromal cells in the reactor in the absence of the organ-function cells.
摘要:
A process for the removal of ammonium from aqueous liquids, especially from fermentation broths, is disclosed. The process uses a cation exchanger membrane which separates a liquid on a donor side that is to be depleted of NH.sub.4.sup.+ from a solution on an acceptor side whose pH is higher than on the donor side. Because of the equilibriumNH.sub.4.sup.+ .revreaction.NH.sub.3 +H+there is on the acceptor side increased formation of NH.sub.3. This is continuously removed, in particular by reducing the pressure and/or passing through inert gas, or by selective transport through another microporous membrane into an acid protonation solution, so that a NH.sub.4.sup.+ concentration gradient is maintained across the membrane. A similar content, apart from the ammonium concentration, of concomitant cations on the donor and acceptor side and/or a high ratio of the solution volumes on the donor side and the acceptor side ensures that the solution on the donor side to be depleted of NH.sub.4.sup.+, does not lose concomitant ions. A suitable apparatus comprises a flow section which can be coupled into a bypass and has a cation exchanger limiting membrane which is simultaneously a limiting wall of an acceptor chamber. The acceptor chamber may contain devices for pH control and NH.sub.3 removal or these may be contained in a flow section.