Optimization of Chaetoceros calcitrans (Paulsen) Takano 1968 Biomass Production via Fed‐Batch Culture Mode

This study investigated the effectiveness of adopting a fed‐batch culture mode with intermittent feeding of culture media to enhance the biomass production of Chaetoceros calcitrans . Three experimental runs were undertaken, each comprising four cycles. The nutritional composition of the C. calcitrans biomass produced was evaluated. The experiment yielded a consistent production of C. calcitrans dry biomass, with outputs of 257.01, 251.88, and 252.41 g obtained in a cultivation period of 28 days per cycle. The initial inoculum concentrations for each run were high, measuring 4.2 × 10 7 , 4.2 × 10 7 , and 4.4 × 10 7 cells mL −1 , respectively. A consistent increase in cell density and dry biomass was observed across all cycles. The cell density at the harvesting point was between 7.3 × 10 7 and 1.10 × 10 8 cells mL −1 . The nutritional analysis of the C. calcitrans biomass revealed that protein comprised the largest proportion of the total biomass at 41.8 ± 0.7%, followed by carbohydrates at 27.2 ± 0.1% and lipids at 11.3 ± 0.6%. The biomass contained a total of 17 amino acids, comprising 43.2% essential amino acids and 56.7% non‐essential amino acids, with the highest concentration observed for glutamic acid (17.6 ± 0.1%). The fatty acid composition of C. calcitrans was recorded with predominant polyunsaturated fatty acids (PUFAs) (44.6 ± 0.2%). The results suggest a possible cost‐saving mechanism, as the culture mode adopted yielded higher microalgal biomass production while retaining a good range of nutritional profiles of C. calcitrans biomass.