Enhanced docosahexaenoic acid production by reinforcing acetyl-CoA and NADPH supply in Schizochytrium sp. HX-308
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Docosahexaenoic acid (DHA) production in Schizochytrium sp. HX-308 was evaluated by detecting enzymatic activities of ATP:citrate lyase (EC 188.8.131.52), malic enzyme (EC 184.108.40.206) and glucose-6-phosphate dehydrogenase (EC 220.127.116.11) at different fermentation stages. According to the analysis, a regulation strategy was proposed which reinforced acetyl-CoA and NADPH supply at a specific fermentation stage. DHA content of total fatty acids was increased from 35 to 60% by the addition of 4 g/L malic acid at the rapid lipid accumulation stage. Total lipid content also showed an apparent increase of 35% and reached 19 g/L when 40 mL ethanol/L was added at the late lipid accumulation stage.
KeywordsDHA Acetyl-CoA NADPH Schizochytrium sp.
This work was financed by the National Natural Science Foundation of China (No. 20606018), the Ministry of Science and Technology of China (National Basic Research Program of China (No. 2007CB707805)) and Scientific Research Project for Post-graduate in Jiangsu Province of China (No. CX07s_032z). We also thank Prof. Walt Johnson for his language assistance with this paper.
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