Figure 5 The effect of temperature downshift on HP cell metabolism in bioreactors. (●, black) constant culture (■, red) temperature downshift culture. (a) Glucose concentration. (b) Lactate concentration. (c) NH4+ concentration. (d) Significance analysis of lactate concentration on day 8, day 10, and day 12. Samples were taken at 12-h intervals and experimental values represent three biological replicates ± SD. Two-tailed Student’s t-test was performed using GraphPad Prism 8.0 ((*) p < 0.05, (**) p < 0.01, (***) p < 0.001 and (****) p < 0.0001).