Abstract
We investigated the effect on growth and photosynthesis of Meristotheca papulosa (Montagne) J. Agardh using four different light emitting diodes (LEDs) and a fluorescent light. The relative growth rates under green LEDs was obtained high values, but that under blue LEDs and red LEDs were obtained low value. Under a blue LEDs condition, the thallus color changed to red more during the culture. The gross photosynthetic rate under green LEDs was showed the highest value within all light sources, whereas that under a red LEDs condition was showed low value. Thus, it was clarified that the growth and photosynthesis of M. papulosa were promoted by using green LEDs, and were inhibited by using red LEDs. For M. papulosa, green LEDs promoting growth and blue LEDs changing the color of thalli to red will be used effectively to produce more valuable products in the future.
