The effect of high temperature and salt on the metabolic heat rate of Chlorella cells

The metabolic heat rate of plants is an integral indicator of the state of the organism. The metabolic heat rate reflects changes in all the anabolic and catabolic processes in plant cells between optimal and extreme conditions. The present studies determined the effects of extreme temperatures (45 degrees C) and high NaCl concentrations (450 mM) on the rate of heat evolution by Chlorella cells. At first, the rate of heat production increases as compared with the control; thereafter it decreases to a steady-state value which is lower than that of the the control. The decrease in metabolic rate may be connected with changes in metabolic processes associated with adaptation of the organism to stress condition. (C) 1998 Elsevier Science B.V.