Following the initial evaluation of eight species of microalgae and cyanobacteria, three of the most promising strains were selected based on their biostimulant properties and nutrient content. These strains are Chlorella sp., Chlorella vulgaris, and a mixed microalgal culture.
The selected cultures were re-cultured under autotrophic conditions in optimal synthetic culture media, while an experimental design was applied to investigate the effect of critical culture parameters. Specifically, the effects of temperature, light intensity, and photoperiod were studied through alternating light and dark cycles, with the aim of maximizing biomass production and growth rate.
The results of the experiments are being used to determine the optimal operating conditions to be applied on a larger scale, as well as for the design and operational optimization of the project’s open photobioreactor.
At the same time, tests are continuing to assess the effect of the biomass produced on plant growth, with the aim of investigating how different cultivation conditions affect the biostimulant properties of microalgae.
Figure 5: Cultivation of the 3 most promising microalgal species under different combinations of light intensity, photoperiod and temperature as optimization factors.