Cost of nutrients is one of the major contributors to the production cost of docosahexaenoic acid (DHA) by thraustochytrids, and this remains the main challenge for economical and sustainable production of DHA. In the present study, cassava pulp (CP) was investigated as an alternative low-cost carbon source for DHA production by Aurantiochytrium limacinum SR21. Cultivation conditions, i.e., salinity level, type of nitrogen source, and concentrations of glucose and nitrogen sources, as well as pH, were optimized for cell growth. CP was enzymatically hydrolyzed, and used as the base medium, supplemented with artificial seawater salts, for DHA production under fed-batch cultivation. A. limacinum grew well at 18 g/L of NaCl (equivalent to 50% salinity level), and initial glucose concentration of 64 g/L, initial yeast extract concentration of 5 g/L, and pH 7.5 were optimum for cell growth. Fed-batch cultivation, with dissolved oxygen (DO) controlled at 10%, using CP-based medium as the carbon source gave a final cell dry mass of 26.3 ± 2.0 g/L, with 15.5 ± 0.1 g/L of lipid. DHA content in the lipid was 37.4 ± 1.5%, equivalent to 5.8 ± 0.3 g/L, and DHA productivity was 960 mg/(L·d). Medium-based economic analysis showed that an economic yield (EY) of this process was 0.86, which was higher than the 0.81 obtained using glucose as the substrate, assuming the same process and conditions. Overall, the results reveal that CP is a highly feasible feedstock for DHA production by A. limacinum SR21.

养分成本是破囊壶菌生产二十二碳六烯酸 (DHA) 成本的主要因素之一，这仍然是经济和可持续生产 DHA 的主要挑战。在本研究中，研究了木薯浆 (CP) 作为 DHA 生产的替代低成本碳源牛角壶菌SR21。培养条件，即盐度水平、氮源的类型、葡萄糖和氮源的浓度，以及 pH 值，都针对细胞生长进行了优化。CP经酶解，作为基础培养基，辅以人工海水盐，在补料分批培养下生产DHA。A. limacinum在 18 g/L NaCl（相当于 50% 盐度水平）下生长良好，初始葡萄糖浓度为 64 g/L，初始酵母提取物浓度为 5 g/L，pH 7.5 是细胞生长的最佳条件。分批补料培养，溶解氧 (DO) 控制在 10%，使用基于 CP 的培养基作为碳源，最终细胞干质量为 26.3 ± 2.0 g/L，脂质为 15.5 ± 0.1 g/L。脂质中DHA含量为37.4±1.5%，相当于5.8±0.3 g/L，DHA产率为960 mg/(L·d)。以中等为基础的经济分析表明，经济收益率 (安永) 为 0.86，高于假设相同工艺和条件下使用葡萄糖作为底物获得的 0.81。总体而言，结果表明，CP 是一种高度可行的 DHA 生产原料。A. limacinumSR21。