Analysis of functional relationships between the cell quantification variables in the microalgae Chlorella sorokiniana

Abstract

The applications of microalgae are being increasingly explored, as they have a high rate of cell duplication and accumulation of lipids, ranging from 20-50% of their dry weight, reaching up to 80% under appropriate conditions. Their cultivation in artificial conditions has also increased, which has made it important to explore different microalga quantification methods and evaluate its growth kinetics. For algal quantification, it appears that both quantification methods by direct counting in a Neubauer chamber (density) and indirect counting methods such as reading in spectrophotometry (optical density) and dry weight (biomass), are important to validate the results quantification. The objective of this study was to verify the existence of a functional relationship between the variables used to quantify the microalgae Chlorella sorokiniana. For this purpose, linear regression analysis was applied to the variables of cell density, optical density, and dry biomass that were obtained by cultivating the microalgae at different concentrations. Using the equations generated from the regression analysis in Chlorella sorokiniana, it was possible to obtain ​​cell density values between 3 and 3.8 × 106 mL-1 and dry biomass values between 0.1 and 4.3 mg.mL-1 from the optical density values acquired using spectrophotometry with extreme precision, and this method was found to be highly feasible.