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Industrial production of microalgae through photosynthesis, carbon dioxide and water scale, directly into high-energy-density oil molecules.Fatty acid triglyceride carbon chain saturation, it is determined that the algae oil is suitable for biodiesel , Or is suitable as a nutritional product.So saturation is one of the most critical factors determining the quality, use and economic value of algal oil.However, is it possible to rationally design algal oil saturation based on industrial microalgae chassis cells? International cooperation team including the University of Maryland, Peking University, Institute of Hydrobiology, Chinese Academy of Sciences led by the single cell center of Qingdao Institute of Bioenergy and Process Research, Chinese Academy of Sciences, through elucidating and regulating a series of endogenous type II The division and cooperation mechanism of diacylglycerol acyltransferase (DGAT2) has demonstrated that algal oil saturation of industrial microalgae can be custom engineered to push the microalgae cell factory into 'Designer Oil' Era This work was published online at Molecular Plant on October 27th.
Nannochloropsis is a commercial microalga that can be cultivated on a large scale outdoors all over the world and has outstanding advantages such as fast growth, strong ability of carbon dioxide tolerance, strong accumulation of fat and freshwater of seawater, etc. Therefore, it has become One of the main research methods and representatives of bio-energy in the field of bioenergy at home and abroad is one of algae species, which contains both saturated fatty acids (SFA), monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) High content of algae oil suitable as a high quality liquid fuel to serve the energy market; and if PUFA (such as EPA, etc.) content is high, algae oil is more suitable as a human health care products, serving the nutrition and food markets.Therefore, Man-made regulation or even rational design of SFA, MUFA, PUFA ratios in the same chassis cells enables highly controlled and flexible switching of algal oil quality, use, and value. This cellular plant characterizes the need to adapt to changing bioenergy market needs , To minimize the cost of product production and switching is of great significance, and at the same time in harsh extreme environments (such as Mars, etc.) to build based on the oxidation Carbon 'single carbon photosynthesis polygeneration model', flexible and controllable synthesis of human survival essential energy, materials and food has a special strategic value.
Previously, single-cell centers and others found that up to 11 DGAT2 genes were encoded in the marine M. paraspora genome and their final step in catalysing the synthesis of triglycerides was also a critical step. And often only 1 or 2 DGAT2 in higher plants Why does Marine Beauveria bassiana have more than the number of DGAT2 family members known to all species? To answer these questions, researchers, through the expression and functional analysis in yeast, DGAT2A, DGAT2D and DGAT2C have TAG synthase activity, and the three DGAT2 family members prefer to saturate , Monounsaturated and polyunsaturated fatty acyl CoA substrate.On the basis of this, the researchers put forward a further step forward in the liposynthesis mechanism model compared with the previous work (Li, et al, Plant Cell, 2014) DGAT2A, DGAT2D and DGAT2C from three different ancestors formed different but complementary substrate preferences in the long-term co-evolution process, and in the TAG synthesis pipeline Engaged in sophisticated function division and space-time collaboration.
Surprisingly, the relative abundance of DGAT2A, DGAT2D and DGAT2C transcripts is positively correlated with the ratio of SFA, MUFA and PUFA on TAGs, suggesting an elegant and concise algal oil saturation control mechanism.Using this, Further, by rationally controlling the relative abundance of the transcripts between DGAT2A, DGAT2D and DGAT2C, the rational design of the specific gravity of SFA, MUFA and PUFA in algae oil was achieved, resulting in the production of a 'tailored' .This twentieth strains of Pseudotubus aeruginosa TAG products, SFA, MUFA and PUFA specific gravity changes were 1.3 times, 3.7 times and 11.2 times, indicating that in a single industrial microalgae chassis, algae oil as a The use and value of fuel or nutraceuticals have good controllability and plasticity.
This work was completed by Xu Jian from Qingdao Energy Institute, Li Yantao from the University of Maryland and Liu Jin from Peking University, and got the help of researchers such as Hu Qiang and Hu Hanhua from the Institute of Hydrobiology. Yi-Ying Lee, from University of Maryland and Lui Yau-To. This paper and its previous work have been approved by the National Outstanding Youth Fund, 863 Synthetic Biology Program of the Ministry of Science and Technology, the Carbonaceous Gas Biology Manufacturing Project of the Chinese Academy of Sciences, Shandong Natural Science Youth Fund and American Natural Science Foundation support.
