Ocean and Polar Research ISSN:2234-7313(Online) Ocean and Polar Research

Melosira nummuloides (KNU-HAPCC-101), which is a biological resource for fucoxanthin extraction, was separated from single cells, and optimal growth conditions were derived according to temperature, salinity, light intensity, light emitting diode, N:P ratio of culture medium, and dilution ratio of culture medium. These parameters were assessed to ascertain the best culture conditions for the most economical and efficient indoor mass production. The specific growth rate was the highest at 25°C in temperature, but there was no significant difference between 15°C and 20°C. M. nummuloides died at 0 psu in salinity, and the specific growth rate was the highest at 30 psu in respect to salinity. The light intensity was similar in all experimental groups except for 5 µmol photons m^-2 s^-1. The maximum biomass and specific growth rate in the light-emitting diode experiment were revealed at the red wavelength, but the concentration of chlorophyll-a was the lowest at the red wavelength whereas the white wavelength produced the highest chlorophyll-a concentration. In the experiment according to the ratio of nitrogen and phosphorus (N:P) based on the f/2 culture medium, the growth rate was significantly higher in the 15:1 to 50:1 ratio range. The growth rate according to the dilution concentration of the f/2 culture medium was the highest in the f/2 culture medium, but did not show a significant difference from the f/4 culture medium. M. nummuloides can be mass-cultured under conditions of a temperature of 15–25°C, a salinity of 15–35 psu, light intensity of 25–150 µmol photons m^-2 s^-1, and f/4 media concentration level with an N:P ratio 15:1 or more. Based on the data of this study, it is expected that fucoxanthin can be produced in a highly efficient manner through the development of a mass culture system.