As an important substance in daily life, sugar is also a key raw material for industrial bio-manufacturing. Although sugar can be seen everywhere, it is not easy to achieve efficient and precise artificial sugar production.
The traditional “CO₂-biomass resources-sugar” processing process is limited by the energy conversion efficiency of plant photosynthesis; at the same time, due to land degradation and shortage, ecosystem degradation, extreme weather and natural disasters caused by global warming, it depends on sugar The production method of biomass resources faces issues such as raw material supply security and risks.
In order to solve this series of challenges, it is imminent to transform from the traditional sugar production process to the non-sugar biomass resource manufacturing mode.
Recently, the artificial conversion of CO₂ de novo precise sugar synthesis technology developed by Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences has made new progress, which can efficiently realize the de novo and precise artificial synthesis of various hexose sugars, and solve the problem of controllable three-dimensional structure of sugar molecules , which provides a new idea for using CO2 to create sugar products with diverse structures and functions to get rid of the natural synthesis route.
Image source: CCTV news client
This research result is an important breakthrough on the basis of the previous CO2 artificial starch synthesis. At present, the research paper has been published in the Science Bulletin journal under the title of “De novo artificial synthesis of hexoses from carbon dioxide”.
Hexose is a monosaccharide containing 6 carbon atoms, also known as six-carbon sugar, which is widely distributed in nature. The more common ones in life include glucose, fructose, galactose, etc. closely related.
In this research on “artificial sugar production”, the Tianjin Institute of Industrial Biotechnology of the Chinese Academy of Sciences and the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences jointly designed and constructed a system based on enzymatic reactions such as carbon condensation, isomerization, and dephosphorization. The non-natural conversion pathway – the “chemical-enzyme coupling” artificial biosynthesis system, engineered to modify the catalytic properties of enzyme protein molecules, realized the precise control of the synthesis of hexoses with different structures and functions.
Design of artificial hexose synthesis route
Image source: Functional Sugars and Natural Active Substances Research Group, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences
The researchers prepared high-concentration CO₂ and other raw materials in a certain proportion in the reaction solution. Under the action of chemical and enzyme catalysts, four hexose sugars, glucose, allulose, tagatose, and mannose, were finally obtained. The whole set of experiments The reaction time is about 17 hours. Compared with the traditional method of obtaining sugar by planting sugarcane and other crops, the time scale has been spanned from “year” to “hour”; in addition, the efficiency of sugar synthesis is higher than the known results. More than 10 times, reaching 0.67 grams per liter per hour, the carbon fixation synthesis efficiency of glucose reaches 59.8 nanomoles of carbon per milligram of catalyst per minute.
Compared with natural photosynthesis, the sugar synthesis of this “chemical-enzyme coupling” artificial biosynthesis system is more efficient and precise, and the synthesis steps are also simpler. It can precisely control the synthesis of hexose sugars with different structures and functions, and more The most important thing is that the carbon conversion rate of this “chemical-enzyme coupling” artificial biosynthesis system is higher than that of natural plant photosynthesis, and it is also higher than the traditional chemical sugar production and the electrochemical-biological coupling artificial sugar production method , which is the highest level of carbon conversion efficiency in the current artificial sugar route.
Artificial conversion of carbon dioxide to synthesize hexose
Photo source: Photo by Xinhua News Agency reporter Sun Fanyue
“This scientific research achievement is equivalent to constructing a synthetic route that does not exist in nature. It does not depend on land or planting. Its synthetic route is shorter, its synthesis efficiency is higher, and it requires less energy. It can also precisely control the structure of the product.” type, improve the selectivity of the product and reduce the cost of separation in the later stage.” Yang Jiangang, an associate researcher at the Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, said.
In general, this study establishes a method for the synthesis of hexose from carbon-one compounds such as CO2, methanol, and formaldehyde, and realizes the artificial synthesis of hexose with high conversion efficiency and precise and controllable configuration. The conversion of material raw materials to form a variety of artificial sugar products provides a possibility.
In the future, the researchers plan to further expand this “chemical-enzyme coupling” synthesis system to produce sugar molecules that are scarce or even non-existent in nature, such as oligosaccharides, glycosides or sugar alcohols, and use them as raw materials for food and medicine and bio-manufacturing and other fields.