Enhancing DHA Production by Supply FeSO4 and IBA to the Fermentation of Schizochytruim sp.

Abstract:

To enhance DHA production by Schizochytrium sp.AB-610，several promoting factors on growth and DHA synthesis were selected and compared. Fe²⁺ was found with great enhancing effect on the growth of Schizochytrium sp.，and indolebutyric acid（IBA） enhanced both of growth and synthesis of DHA. Based on the above results，supplement of 0.95mM FeSO4 and 6.5 mg/L IBA in 500 mL flask was brought about by the test of Center Composite Design（CCD）. Fermentation parameters and cell morphology in control group were both tested and observed every 12 h during fed-batch cultivation of Schizochytruim sp. AB-610 in 7.5 L fermentor. The fermentation period was divided into 4 phases：adapt phase，balanced growth phase，lipid accumulation phase and lipid turnover phase. Supplement of both FeSO4 and IBA was also scaled up in NBS 7.5 L fermentor. It showed that adding of both promoting factors improved the growth rate and elongated the stage of cell growth obviously，and the final DHA productivity of Schizochytrium sp. increased by 51.22%.