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Effect of ammonium ion and extracellular pH on hybridoma cell metabolism and antibody production
Author(s) -
McQueen Anne,
Bailey James E.
Publication year - 1990
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260351102
Subject(s) - laboratory flask , bioreactor , chemistry , extracellular , ammonium , glutamine , yield (engineering) , metabolism , ammonia , intracellular ph , chromatography , biochemistry , nuclear chemistry , amino acid , organic chemistry , materials science , metallurgy
The effects of NH 4 Cl addition on batch hybridoma cell growth at different external pH values (pH e ) were investigated in a bioreactor at constant pH and dissolved oxygen concentration. In agreement with measurements in flasks, changes in pH e over the range 6.8–7.6 had minor effects on growth. Addition of 3 m M NH 4 Cl had little effect on cell growth while 10 m M NH 4 Cl caused a substantial growth inhibition, Measurements of the effects of pH e and NH 4 Cl concentration on cell metabolism gave similar results for cells grown in flasks in an incubator and in the bioreactor. As pH e decreases, the integral cell yield on glucose increases. There is a correlation between the effects of pH e on glycolysis and previous measurements of its effects on intracellular pH (pH i ). Increases in NH 4 Cl concentration were previously determined to decrease pH i and are shown here to decrease the integral cell yield on glucose. At all pH e values in the absence of NH 4 Cl, glutamine is depleted at the time the maximum cell density is reached. Both pH e decreases and NH 4 Cl concentration increases lead to decreases in the integral cell yield on glutamine. Changes in pH e and in the NH 4 Cl concentration that cause growth inhibition have no effect on the specific antibody production rate for cells grown in flasks in an incubator or in the bioreactor. Changes in the NH 4 Cl concentration have no effect on the quality of the antibody produced, to a first level of characterization.