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Regulation of lipid accumulation in Schizochytrium sp. ATCC 20888 in response to different nitrogen sources
Author(s) -
Jiang Xin,
Zhang Jia,
Zhao Jing,
Gao Ziqing,
Zhang Chunzhi,
Chen Ming
Publication year - 2017
Publication title -
european journal of lipid science and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.614
H-Index - 94
eISSN - 1438-9312
pISSN - 1438-7697
DOI - 10.1002/ejlt.201700025
Subject(s) - food science , docosahexaenoic acid , yeast extract , biomass (ecology) , chemistry , fermentation , biochemistry , nitrogen , biology , fatty acid , polyunsaturated fatty acid , ecology , organic chemistry
Regulation of lipid accumulation in Schizochytrium sp. ATCC 20888 in response to different nitrogen sources was investigated in this study. Nitrogen sources had important effects on the cell growth, lipid accumulation, and docosahexaenoic acid (DHA) percentage in total fatty acids (TFAs). Compared with sole organic nitrogen source, the combination of yeast extract and monosodium glutamate (MSG) greatly enhanced the biomass, total lipids, and DHA percentage in TFAs, but inorganic nitrogen source addition decreased the biomass and total lipids. The results showed that lipids began to accumulate rapidly with the depletion of dissolved ammonia in broth, and the time required for nitrogen exhaustion was extended with increasing nitrogen source concentration. Furthermore, the analysis of isocitrate dehydrogenase (ICDH) and malic enzyme (ME) activities during fermentation process provided insight for the revelation of regulation mechanism of lipid accumulation in Schizochytrium sp. ATCC 20888 in response to nitrogen exhaustion in broth. Practical applications: DHA, an essential nutrient for human health, is widely used in infant formula and functional foods. DHA production by Schizochytrium sp. has recently received extensive attention as the commercial source of DHA to substitute marine fish oil. Nitrogen sources in the cultivation of Schizochytrium sp. have important effects on the cell growth, lipid accumulation, and DHA percentage in TFAs. This study provides valuable guidance for nitrogen source selection for efficient DHA‐rich lipids production by Schizochytrium sp. The combination of yeast extract and MSG enhances the biomass, lipid yield, and DHA percentage in TFAs, but inorganic nitrogen source addition decreases the biomass and lipid yield. The results in this study have important significance in understanding lipid accumulation regulation in Schizochytrium sp. in response to nitrogen sources and providing guidance for DHA‐rich lipid production enhancement.