Impact of light quality on a native Louisiana / sp. co-culture.

Light effect on cultures of microalgae has been studied mainly on single species cultures. Cyanobacteria have photosynthetic pigments that can capture photons of wavelengths not available to chlorophylls. A native Louisiana microalgae () and cyanobacteria ( sp.) co-culture was used to study the effects of light quality (blue-467 nm, green-522 nm, red-640 nm and white-narrow peak at 450 nm and a broad range with a peak at 550 nm) at two irradiance levels (80 and 400 μmol m s) on the growth, species composition, biomass productivity, lipid content and chlorophyll-a production. The co-culture shifted from a microalgae dominant culture to a cyanobacteria culture at 80 μmol m s. The highest growth for the cyanobacteria was observed at 80 μmol μmol m s and for the microalgae at 400 μmol m s. Red light at 400 μmol m s had the highest growth rate (0.41 d), biomass (913 mg L) and biomass productivity (95 mg L d). Lipid content was similar between all light colors. Green light had the highest chlorophyll-a content (1649 μg/L). These results can be used to control the species composition of mixed cultures while maintaining their productivity.