Using Phycocyanin as Spectral Converter on the Growth Parameters and Lipid Content of the Green Microalga Chlorella sp. in a Double Layer Flat Panel Photobioreactor.

The focus of this research is spectral shifting of light using phycocyanin solution extracted from the blue-green microalga Spirulina platensis in order to increase biomass productivity of the green microalga Chlorella sp. Also, lipid and chlorophyll content of the green alga was investigated. With regard to the shift of the spectrum with the phycocyanin solution, a double layer flat panel photobioreactor and two different spectral shifting strategies were used. In each strategy, the effect of two different concentrations of the solution was investigated. In the first strategy, the light passes through the chamber containing the solution and then enters the microalga culture chamber. In the second strategy, the light first enters the culture chamber and then enters the chamber containing phycocyanin pigment. The results showed that the use of phycocyanin pigment by both strategies increased the biomass productivity (P) and the specific growth rate (µmax) with a significant difference compared to the control system; the increase in P for first strategy was up to about 69%. Moreover, the use of phycocyanin solution with a lower concentration had a greater effect on the increase of total chlorophyll content; however, the solution with a higher concentration was more successful in the production of cell lipid content. Using the phycocyanin solution as spectral converter in a double layer flat panel photobioreactor increased the biomass productivity and chlorophyll content.

Effect of fluorescent dye positioning and concentration on the growth parameters and lipid content of Chlorella sp. in a flat panel photobioreactor.

In this study, two different concentrations of fluorescent dye Rhodamine 6G (R6G) with two different strategies were used in a double layer flat panel photobioreactor (PBR) for investigation of its effect on growth parameters of microalgae Chlorella sp. Results showed that in the first strategy, when the light passed through the dye before reaching the broth, biomass productivity rate (P) and maximum specific growth rate (µmax) relative to control case, were increased up to 60 and 23% respectively. Increasing in these parameters were more, for the low dye concentration. Also, in the second strategy, when the light passed through the microalgae before reaching the dye solution, P and µmax for lower concentration increased about 9 and 15%, respectively. But using high dye concentration growth of the algae was decreased. Furthermore, using R6G caused increase in the lipid and chlorophyll content of the microalgae Chlorella sp.