Assessment of phosphorescent paint effects on microalgae cultivation

Light is the most important factor involved in the growth of photosynthetic organisms, and low efficiency of artificial light systems imposes higher cultivation costs. Phosphorescent paints can emit light for a few hours, and so may be appropriate to accumulate scattered light. In this study, the effects of blue and green phosphorescent paints on growth rate, biomass production and chlorophyll content of three different microalgae, Scenedesmus dimorphus, Chlamydomonas reinhardtii and Chlorella vulgaris were investigated. These strains were cultivated in broth medium in three glass bowls. Half of the first two bowls was stained with blue or green phosphorescent paints (B and G treatment), while the third one was unstained and used as the control (C treatment). All measured parameters were higher in B. The results indicate that partial staining of culturing bowls by blue phosphorescent paint can be an economic approach to increase light efficiency in cultivating microalgae.