Regulation of glucose and glycerol for production of docosahexaenoic acid in Schizochytrium limacinum SR21 with metabolomics analysis
Regulation of glucose and glycerol for production of docosahexaenoic acid in Schizochytrium limacinum SR21 with metabolomics analysis
复制标题
通过代谢组学分析调节裂殖壶菌 SR21 中葡萄糖和甘油生产二十二碳六烯酸
DOI：
10.1016/j.algal.2021.102415
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发表时间：
2021-07-26
影响因子：
5.1
通讯作者：
He, Ning
中科院分区：
文献类型：
--
作者：
Li, Zhipeng;Meng, Tong;He, Ning
二十二碳六烯酸(DHA)是omega-3多不饱和脂肪酸(PUFAs)中的一员，在改善人类健康方面起着至关重要的作用。裂殖酵母SR21被认为是一种潜在的生产DHA的微藻。碳源调节红毛藻的细胞代谢和多不饱和脂肪酸的合成。通过摇瓶和补料分批培养，研究了甘油和葡萄糖对淡色链霉菌SR21的生物量、生长速率和DHA含量的影响。摇瓶培养中，以葡萄糖为唯一碳源时细胞生长速率最高(12.2g/L/天)，以甘油为唯一碳源时细胞中DHA含量达到最大值(46.88%)。分批补料发酵结果表明，与以葡萄糖为唯一碳源相比，甘油的生物量为171g/L，DHA产量为40.7g/L，DHA产量为223.8 mg/L/h。我们结合了两种碳源的优点，开发了一种新的混合碳源(葡萄糖和甘油)的两段补料分批发酵策略。与单一碳源相比，该碳源的DHA产量提高了229.8 mg/L/h。比较代谢组学分析表明，在培养基中添加甘油上调了戊糖磷酸和糖酵解途径。此外，三元酸循环和甲氧戊酸途径也受到抑制。这些结果为提高红毛链霉菌SR21的DHA产量提供了代谢基础。
Docosahexaenoic acid (DHA), a member of omega- 3 polyunsaturated fatty acids (PUFAs), plays an essential effect in the amelioration of human health. Schizochytrium limacinum SR21 is considered as a potential microalgae for DHA production. The carbon source regulates cell metabolism and PUFAs synthesis in S. limacinum. Flask and fed-batch cultivations were conducted to explore the influence of glycerol and glucose on the biomass, growth rate, and DHA content of S. limacinum SR21. In flask cultivation, the highest cell growth rate (12.2 g/L/day) was obtained when glucose was employed as the sole carbon source, whereas the DHA content reached the maximum value (46.88%) in the medium with glycerol as the sole carbon source. Fed-batch fermentation showed that glycerol had comparable biomass 171 g/L, higher DHA yield (40.7 g/L), and higher DHA production rate (223.8 mg/L/h) compared with glucose as the sole carbon source. We combined the advantages of the two carbon sources and developed a new two-stage fed-batch fermentation strategy using mixed carbon sources (glucose and glycerol). This strategy showed an increase in DHA production rate (229.8 mg/L/h) in comparison with the sole carbon sources. Comparative metabolomics analysis indicated that glycerol added in the medium up-regulated the pentose phosphate and glycolysis pathways. Moreover, tricarboxylic acid cycle and mevalonate pathway were dampened. These outcomes provide metabolic basis for enhancing DHA production rate by S. limacinum SR21.