Valeric and butyric acid supplementation increased qp under mild hypothermia.
Supplementation with 1 mM valeric acid at 31 °C led to the highest productivity.
Valeric acid was less cytotoxic than butyric acid.
Percentage of cells in G0 + G1 phase was higher at 31 °C, mainly with valeric acid.
The proliferation state of cells [S/(G0 + G1) ratio] inversely correlated with qp.