Metabolism of PER.C6TM cells cultivated under fed-batch conditions at low glucose and glutamine levels

✍ Scribed by Luis Maranga; Charles F. Goochee

• Publisher: John Wiley and Sons
• Year: 2006
• Tongue: English
• Weight: 205 KB
• Volume: 94
• Category: Article
• ISSN: 0006-3592
• DOI: 10.1002/bit.20890

✦ Synopsis

Abstract

This is the first study to examine PER.C6^TM^ cell glucose/energy and glutamine metabolism with fed‐batch cultures at controlled low glutamine, low glucose, and simultaneous low glucose and low glutamine levels. PER.C6^TM^ cell metabolism was investigated in serum‐free suspension bioreactors at two‐liter scale. Control of glucose and/or glutamine concentrations had a significant effect on cellular metabolism leading to an increased efficiency of nutrient utilization, altered byproduct synthesis, while having no effect on cell growth rate. Cultivating cells at a controlled glutamine concentration of 0.25 mM reduced q~Gln~ and q by approximately 30%, q~Ala~ 85%, and q~NEAA~ 50%. The fed‐batch control of glutamine also reduced the overall accumulation of ammonium ion by approximately 50% by minimizing the spontaneous chemical degradation of glutamine. No major impact upon glucose/energy metabolism was observed. Cultivating cells at a glucose concentration of 0.5 mM reduced q~Glc~ about 50% and eliminated lactate accumulation. Cells exhibited a fully oxidative metabolism with Y of approximately 6 mol/mol. However, despite no increase in q~Gln~, an increased ammonium ion accumulation and Y were also observed. Effective control of lactate and ammonium ion accumulation by PER.C6^TM^ cells was achieved using fed‐batch with simultaneously controlled glucose and glutamine. A fully oxidative glucose metabolism and a complete elimination of lactate production were obtained. The q~Gln~ value was again reduced and, despite an increased q compared with batch culture, ammonium ion levels were typically lower than corresponding ones in batch cultures, and the accumulation of non‐essential amino acids (NEAA) was reduced about 50%. In conclusion, this study shows that PER.C6^TM^ cell metabolism can be confined to a state with improved efficiencies of nutrient utilization by cultivating cells in fed‐batch at millimolar controlled levels of glucose and glutamine. In addition, PER.C6^TM^ cells fall into a minority category of mammalian cell lines for which glutamine plays a minor role in energy metabolism. © 2006 Wiley Periodicals, Inc.