Effect of glucose on the cultivation of mammalian cells

Most of the glucose consumed by mammalian cells cultivated in vitro is converted to lactate. The glucose consumption rate appears to be affected by glucose concentration. In a batch cultivation of cells the glucose concentration can be manipulated at a low level by programmed feeding of glucose. In such a culture the specific consumption rate of glucose and the fraction of glucose converted to lactate can be reduced. This reduced conversion rate of glucose to lactate appears to coincide with an increased oxygen uptake rate. A possible consequence of such programmed feeding of glucose is the increased oxidation of glutamine and the concurrent increased production of ammonium. For the cultivation of hybridoma cells high concentrations of ammonium and lactate can be growth inhibitory. It is suggested that the identification of the optimum cultivation conditions is necessary if such a programmed feeding is to be used to increase cell concentration and medium utilization efficiency.