Optimization of the algal species Chlorella miniata growth: Mathematical modelling and evaluation of temperature and light intensity effects

Abstract

Growth of Chlorella miniata , a green microalga was investigated during this study under various temperature and light intensity values with the purpose of determining growth rate changes of the microalgae with cultivation parameters, experiments were carried out using airlift photobioreactors with a study volume of 6 L. Culturing conditions were between 66 and 385 μmol photon m −2 s −1 and between 14 and 30 °C for light intensity and ambient temperature, respectively. Acquired data were then used to test various mathematical models for coherency with experimental results. Aiba Model for light intensity and Skewed Normal Distribution Model for temperature parameters performed superior compared to the rest of the mathematical models used during the study. Utilizing both mathematical models a novel model was deduced to express effects of both light intensity and temperature parameters in combination on algal growth. Then the developed model was used to calculate the optimum growth condition of the species. The proposed mathematical model showed good coherency with experimental data and an average relative error of 1.97% for both temperature and light intensity effects on algal growth. The theoretical optimum temperature and light intensity for the maximum specific growth rate were calculated to be 22.43 °C and 291.5 μmol photon m −2 s −1 respectively. • The theoretical optimum temperature for growth was calculated to be 22.43 °C. • The theoretical optimum light intensity for growth was calculated to be 291.5 μmol photon m −2 s −1 . • Aiba model was selected for describing light intensity growth relationship. • Skewed Normal Distribution Model was selected for temperature growth relationship.