The Effect of Sodium Bicarbonate Concentrations on Growth and Biochemical Composition of Chaetoceros gracilis Schutt

Abstract

The unicellular marine diatom, Chaetoceros gracilis Schutt, has been commonly used as an important live food for crustacean larvae in Thailand. In this study, the effects of sodium bicarbonate concentrations (0.05, 0.50 and 5.00 g L^-1) on growth and biochemical composition of C. gracilis were investigated. C. gracilis was cultured with modified f/2 medium at 25 ± 1°C and continuous illumination (5,000 Lux). C. gracilis cells were harvested only once after the culture period at 60 h to analyze carbohydrates, protein and total lipid contents. The results showed that the accumulation of carbohydrates and total lipid in C. gracilis was highest in 0.05 g L^-1 sodium bicarbonate while cell density was unaffected as it was not different (P>0.05) from that of the control group (no sodium bicarbonate added). These results can be applied for nutritional improvement of this diatom used as live feed for marine animal larviculture.