Issue 19/2021 - Breakthrough in CO2 synthetic starch technology

Recently, the Tianjin Institute of Industrial Biotechnology of the Chinese Academy of Sciences (hereinafter referred to as "Tianjin Institute of Workers") has made a breakthrough in starch synthesis, realizing the de novo synthesis of carbon dioxide to starch for the first time in the world, and the relevant results were published
in Science on September 24.

At present, starch is mainly produced by corn and other crops through natural photosynthesis to fix carbon dioxide, synthesis and accumulation involve about 60 steps of metabolic reactions and complex physiological regulation, and the theoretical energy conversion efficiency is only about
2%.

The research team used a similar "building block" method to design a new pathway of unnatural carbon dioxide fixation and artificial synthesis of starch from scratch with 11 steps of the main reaction, and realized the total synthesis
from carbon dioxide to starch molecules for the first time in the laboratory.

Tianjin Institute of Technology and Chemistry, together with Dalian Institute of Chemical Physics, Chinese Academy of Sciences, uses chemical catalysts to reduce high concentrations of carbon dioxide to carbon-one compounds under the action of high-density hydrogen energy, and then designs and constructs a new carbon-polymerization enzyme, polymerizes carbon-one compounds into carbon-three compounds according to the principle of chemical glycan reaction, and finally polymerizes carbon-three compounds into carbon-six compounds through biological pathway optimization, and then further synthesizes linear chain and amylopectin
.

Preliminary laboratory tests have shown that synthetic starch is about 8.
5 times
more efficient than starch produced in traditional agriculture.
According to the current technical parameters, under the condition of sufficient energy supply, the annual starch output of a bioreactor of 1 cubic meter is theoretically equivalent to the average annual starch yield
of corn planted on 5 acres of land.

The relevant results make it possible to transform the traditional agricultural planting mode of starch production to the industrial workshop production mode, and provide a new technical route
for the synthesis of complex molecules from carbon dioxide raw materials.
If the cost of the system process can be reduced to be economically feasible compared to agricultural cultivation in the future, it will be possible to save more than 90% of arable land and fresh water resources, while reducing the environmental impact
of pesticides and fertilizers.

The Chinese Academy of Sciences said that the achievement is still in the laboratory stage, there is still a long way to go from practical application, and the follow-up needs to achieve a breakthrough
from the concept of "0 to 1" to "1 to 10" and "10 to 100" as soon as possible.
The Chinese Academy of Sciences will integrate relevant scientific and technological forces and continue to support the in-depth advancement
of this research.