In September last year, Chinese scientists made major breakthroughs in the field of synthetic biology, and for the first time in the world, the laboratory achieved carbon dioxide to starch from scratch.
So, in addition to synthetic starch, can carbon dioxide be synthesized? A few days ago, the latest research by the Nagawa Research Group of the University of Electronic Science and Technology, the Shenzhen Advanced Technology Research Institute of the Chinese Academy of Sciences, and Zeng Jie’s research group of China University of Science and Technology showed that the carbon dioxide composite the carbon dioxide was composed of the combination of biological synthesis through electrical catalytic combination of biological synthesis. High -concentration, further use of microorganisms to synthesize glucose and fatty acids.
On April 28th, Beijing time, the results were published in the form of a cover article in the international journal "Nature · Catalytic". "The work provides new technologies for artificial and semi -artificial synthesis ‘food’.
Li Can, an academician of the Chinese Academy of Sciences and director of the Catalytic Professional Committee of the Chinese Chemistry Association.
Carbon dioxide is transformed into carbon monoxide first, and then how to synthesize carbon dioxide how to synthesize glucose and fatty acids? "First of all, we need to convert carbon dioxide into ‘ingredients’ for microorganisms to be used for microbial fermentation.
"Zeng Jie said that clean and efficient electrocatalytic technology can work under normal temperature and normal pressure, which is an ideal choice to achieve this process.
As for what kind of "raw materials" to be transformed, the researchers target acetic acid. Because acetic acid is not only the main ingredient of vinegar, but also an excellent biological synthetic carbon source, which can be converted into other biomass such as glucose. "Direct electrolytic carbon dioxide can get acetic acid, but the efficiency is not high, so we decided to get two steps in two steps -first efficiently get carbon monoxide, and then from carbon monoxide to acetic acid.
"Zeng Jie said. At present, the electrical synthesis efficiency of carbon dioxide to acetic acid (that is, the efficiency of acetic acid Faraday) and purity are not satisfactory.
In this regard, scientific researchers have found that carbon monoxide can be synthetic synthetic synthetic synthetic synthetic synthetic synthetic acetate Faradid efficiency of carbon monoxide can reach 52%. "In actual production, increasing the current can increase power, but it may reduce the efficiency of Faraday." Xia Chuan said that it is like extending the daily working hours from 8 hours to 12 hours. Although the time is longer, the work efficiency will decline. "Therefore, when we raised the maximum bias density to 321mA/CM2 (mia/square centimeters), the efficiency of acetic acid Faraday remained at 46%, and it could better maintain the balance between high current and high Faraday efficiency.
"However, the acetic acid produced by conventional electrical catalytic devices is mixed with a lot of electrolyte salt and cannot be used directly for biological fermentation. Therefore, in order to" feed "microorganisms, we must not only improve the transformation efficiency, ensure the number of" food ", Pure acetic acid containing electrolyte salts to ensure the quality of "food". "We use the new solid electrolyte reaction device to use solid electrolyte instead of the original electrolyte salt solution, which directly obtains pure acetate solution that is not required to further separate.
"Xia Chuan introduced that using this device can surpass the acetic acid acetate solution with a purity of 97%continuously in 140 hours.
After the "feed" of acetic acid was "fed" to the winemaking yeast and generated glucose and fatty acids to get acetic acid, scientific researchers began to try to use the microorganisms of winemaking to synthesize glucose.
"Brewery yeast is mainly used for fermentation of foods such as cheese, steamed buns, wine and other foods, and is often used as a model creature for microbial manufacturing and cell biology.
"Yu Tao said that the process of using wine yeast through acetic acid to synthesize glucose is like" jealous ". The wine yeast is constantly" jealous "to synthesize glucose.
However, in this process, the winemaking is also metabolized for some glucose, so the output is not high.
In order to solve this problem, the scientific research team abolished the ability of wine yeast metabolic glucose through three key enzyme elements of metabolic glucose in wine yeast. After knockout, under the condition of the fermentation of the engineering yeast strains in the experiment, the synthetic glucose output reaches/L (gram/liter).
"The use of model biological brewing yeast ‘to synthesize glucose at the level of grade level from scratch, which represents the high production level and development potential of this method." Yu Tao said that in order to further increase the synthetic glucose production, it must not only abolish the winemaking wine The ability of yeast metabolism to strengthen its ability to accumulate glucose itself.
As a result, scientific researchers knocked on two enzyme elements with metabolic glucose capacity, and inserted glucose phosphue enzyme components from Panbin and E. coli.
Yu Tao said that these two enzymes can convert the phosphate molecules in other pathways in the yeast into glucose, which enhanced the ability of yeast to accumulate glucose. The glucose output of the planting yeast strains after the reconstruction reached/L, and the output increased by 30%. In the process of using acetic acid preparation, researchers have strengthened the ability of yeast cells to generate fatty acids through similar gene editing technology. The production of yeast strains on the modified fatty acids reaches/L (mg/liter).
The new catalytic method helps Deng Zixin, the director of the China Academy of Sciences of the Chinese Academy of Sciences and the director of the National Key Laboratory of the Microbiology of Shanghai Jiaotong University, and believes that this research work has opened up a new work of electrochemical combination of living cells to prepare grain products such as glucose products Strategy provides new examples for further developing new -type agriculture and biological manufacturing industries based on power -driven, which is an important direction for carbon dioxide use.
In recent years, with the rapid rise of new energy power generation, carbon dioxide reduction technology has already possessed the potential to compete with traditional chemical technology that relies on fossil energy. Therefore, the efficient process of studying carbon dioxide electricity reducing high value -added chemicals and fuels is considered one of the important research directions to achieve zero carbon emissions by academic circles. At present, it is still a huge challenge how to transform carbon dioxide into long chain -rich long -chain -rich long -chain molecules. Xia Chuan said: "In order to avoid the limitation of the product of carbon dioxide electricity reduction, the carbon dioxide reduction process can be considered coupled with the biological process, and the electrocatalytic products are used as an electronic carrier for the chemical products of the microorganisms to ferment the carbon chain in the subsequent fermentation of the carbon chain. Production and life. "Appropriate electronic carriers are crucial to microorganisms.
Because the gas phase products restored by carbon dioxide are difficult to dissolve in water, and the efficiency of biological utilization is low, the liquid phase product of carbon dioxide reduction is given priority to the electronic carrier of biological fermentation.
However, the liquid product obtained in ordinary electrochemical reactors is a mixture mixed with electrolyte salt, which cannot be directly used for biological fermentation.
The development of solid -state electrolyte reactors effectively solves the problem of separation of carbon dioxide electricity reduction liquid products. It can continuously and stable to provide liquid electronic carrons for microorganism fermentation. The advantage of microorganisms is that the product diversity is very high and can synthesize many compounds that cannot be efficient through artificial production or artificial production.
Zeng Jie said: "Next, we will further study the same match and compatibility of the two platforms of electrocatalytic and biological fermentation." In the future, if you want to synthesize starch, make pigment, produce drugs, etc. Change, replacement of microorganisms used for fermentation can be achieved.