LDH-C can be differentially expressed during fermentation of CHO cells

Expression of CHO mRNA was measured with special microarrays from the Consortium for Chinese Hamster Ovary (CHO) Cell Genomics led by Prof. Wei-Shou Hu of the University of Minnesota and Prof. Miranda Yap of the Bioprocess Technology Institute of A*STAR, Singapore (http://hugroup.cems.umn.edu/CHO/cho_index.html). Cultivation experiments were performed in small scale 2L stirred tank bioreactors. During fermentation a temperature shift of -3°C was performed. This was accompanied by a reduction of the cell specific lactate production rate. The analysis of transcriptome samples before and after the temperature shift with microarrays showed several changes in the expression of available gene markers. LDH-C expression raised about 2 fold after temperature shift. LDH-A did not change. As LDH-C is known to be a specialized isoenzyme in sperm cells for consuming lactate in a lactate containing milieu, LDH-C could be proposed as a target for genetic engineering, facilitating lactate consumption in the late phase of high cell density cultures and prolonging longevity of CHO production cultures by reducing lactate and base accumulation.