Effects of glucose supply on myeloma growth and metabolism in chemostat culture.

The effects of the glucose supply on growth and metabolism of an SP2/0 derived recombinant myeloma cell line were studied in chemostat culture during growth on IMDM medium at a fixed dilution rate of 0.032 h-1. Lowering of the feed medium glucose concentration from 25.0 to 1.4 mmol/L resulted in a decrease of steady-state viable cell concentration from 1.9 x 10(9) to 1.0 x 10(9) L-1, whereas viability remained above 90%. Mass balances indicated that only a minor amount of glucose was utilized via the TCA cycle irrespective of the glucose concentration in the feed medium. The apparent biosynthetic yield of cells from ATP was independent of the ratio between the specific glucose and glutamine consumption rate. It is concluded that the primary role of glucose is the provision of intermediates for anabolic reactions. In addition, glucose may play an indirect catabolic role in the process of glutaminolysis by providing the pyruvate for the transamination of glutamate to alanine and alpha-ketoglutarate. At low glucose concentrations in the feed medium, glutamine is probably the sole energy source for this myeloma in chemostat culture.