EFFECTS OF DIFFERENT LIGHT SPECTRUMS ON GROWTH AND PROTEIN CONTENT OF Chaetoceros calcitrans

Microalgae have recently received much attention as a new biomass source for protein, lipid, fatty acids and natural pigments. This makes microalgae a potentially rich source of chemical products with applications in the feed, food, nutritional and pharmaceutical industries. The growth and biochemical composition of microalgae are known to be greatly influenced by light. Limited availability of natural light (e.g. sunlight) due to diurnal cycles and seasonal variations impedes the viability of their production. Artificial lights such as fluorescent lamps are commonly used as a substitute to overcome light limitations. However, some of these light sources have high energy consumption. Therefore, energy-saving alternatives such as light emitting diodes (LEDs), with specific spectrums are encouraged to be integrated into culture systems to achieve faster growths and high quality biomass at a reduced operational cost. Chaetoceros calcitrans is widely used as a live feed for shrimp larvae. The growth and protein content of this commercially important species cultivated under 3 different light spectrums - blue, red LED, and compact fluorescent lamp (CFL; control) were evaluated in this study.

The highest specific growth rate (SGR) for C. calcitrans was blue and red LED treatments, which were significantly higher from the rest of the treatments (p<0.05). The highest protein content was obtained in blue LED treatment (p<0.05) (Table 1). These results indicate that blue and red LED promotes the growth of C. calcitrans. However, the protein content of the species was only higher when cultivated under blue LED.