种子培养基成分对裂殖壶菌发酵产DHA的影响

考察种子培养基中谷氨酸钠质量浓度和NaCl质量浓度（盐度）对Schizochytrium sp. HX-308菌种质量及发酵性能的影响。结果表明：40 g/L谷氨酸钠条件下培养菌种,发酵后DHA质量分数达到（53.25±0.48）%,而其油产量、油脂质量分数和DHA产量分别为（24.9±0.4）g/L、（45.2±0.6）%、（8.6±0.35）g/L; 利用不含谷氨酸钠的种子培养基发酵,其油产量、油脂质量分数和DHA产量分别为（30.1±0.8）g/L、（54.3±0.5）%、（12.1±0.5）g/L,比含40 g/L谷氨酸钠时分别提高了20.88%、20.13%和40.70%,为菌种驯化提供了新的思路和方向。此外,低盐度培养条件有利于菌种生产性能的发挥,6.25 g/L NaCl条件下发酵后油质量分数、DHA产量及DHA质量分数最高,分别为（62.1±0.8）%、（10.0±0.3）g/L、（48.97±0.42）%。

Effects of culture media on docosahexaenoic acid production by Schizochytrium sp.

The effects of monosodium glutamate （MSG） concentration and salinity in seed medium on strain quality and fermentation performance of Schizochytrium sp. HX-308 were investigated. The highest DHA content reached （53.25 ± 0. 48 ） % with 40 g/L MSG in seed medium and its lipid yield, lipid content and docosahexaenoie acid （DHA） yield reached （24.9 ± 0.4 ） g/L, （45.2 ± 0. 6 ） % , （ 8.6 ± 0. 35 ） g/L, respectively. It was interesting that strain cultured in seed medium without MSG could obtain better fermentation performance. Lipid yield, lipid content and DHA yield reached （30. 1 ± 0.8 ） g/L, （54.3 ±0. 5）%, and（12. 1 ±0. 5） g/L, respectively. They were increased by 20. 88% ,20. 13%, and 40.70% than those of 40 g/L MSG, providing new ideas and theoretical basis for future strain acclimatization. In addition, low salinity condition was favorable to exert the productive potentiality of the strain. 6.25 g/L NaCl was the best salinity in the seed medium. Lipid content, DHA yield, and DHA content of Schizochytrium sp. HX-308 after fermentation reached the maximum values of （62. 1 ± 0.8 ） %, （ 10.0 ± 0.3 ） g/L, and （48.97 ± 0.42） %, respectively.