A systematic study on the effects of dynamic environments on microalgae concentration

The usage of calibration curves for the determination of microalgae concentration is common, and it consists of a correlation between the optical density and the number of cells. Although this tool is very useful for determining the concentration of microalgae, it requires the generation of a new calibration curve when the environmental conditions (e.g., temperature, light, etc.) change, since the size of microalgae may vary from one condition to another. We propose a novel methodology to determine the number of microalgae in a solution, emphasizing a correlation with optical density and the size distribution of cells. Considering that microalgal physiology is affected by environmental conditions, the proposed procedure allows for the calculation of the concentration of microalgae in changing ambient conditions without requiring the preparation of additional calibration curves. © 2019 Elsevier B.V.