Temperature Dependence of Population Growth in a Green Microalga: Thermodynamic Characteristics of Growth Intensity and the Influence of Cell Concentration

Growth intensity of the green alga, Scenedesmus obliquus, was measured in autotrophic cultures, diluted once daily, between 20 and 30 °C in a light-dark cycle of 16 : 8 h at initial optical densities between 0.02 and 1.2. Arrhenius analyses of the results showed linear relationships be­tween growth intensity and temperature below the temperature optimum. The temperature effects on growth, activation energy, deactivation energy and normalized Q 10 values were signifi­cantly influenced by the amount of available light energy per unit biomass. The temperature dependence of nutrient-limited growth was not considered.