starch from co2

starch from co2

Creating starch from co2 is not a new process. Plants do it all the time. But Chinese researches now discovered a way to do it much more efficiently in a lab. That would potentially save up to 90% of farm land, water, fertiliser and pesticides, they claim.

Chinese scientists recently reported a new technology for artificial starch synthesis from carbon dioxide (CO2). The results were published in Science on September 24.

The new route makes it possible to shift the mode of starch production from traditional agricultural planting to industrial manufacturing, and opens up a new technical route for synthesizing complex molecules from CO2, reports Eurekalert.

Starch is the major component of grain as well as an important industrial raw material. At present, it is mainly produced by crops such as maize by fixing CO2 through photosynthesis. This process involves about 60 biochemical reactions as well as complex physiological regulation. The theoretical energy conversion efficiency of this process is only about 2%.

A sustainable production of starch and use of CO2 are urgently needed to solve the food crisis and climate change. Designing new ways to replace plant photosynthesis for converting CO2 to starch can contribute to achieve that.

To address this issue, scientists at the Tianjin Institute of Industrial Biotechnology (TIB) of the Chinese Academy of Sciences (CAS) designed a chemoenzymatic system as well as an artificial starch anabolic route consisting of only 11 core reactions to convert CO2 into starch.

The abstract of the research says: “Starches, a storage form of carbohydrates, are a major source of calories in the human diet and a primary feedstock for bioindustry. We report a chemical-biochemical hybrid pathway for starch synthesis from carbon dioxide (CO2) and hydrogen in a cell-free system. The artificial starch anabolic pathway (ASAP), consisting of 11 core reactions, was drafted by computational pathway design, established through modular assembly and substitution, and optimized by protein engineering of three bottleneck-associated enzymes. In a chemoenzymatic system with spatial and temporal segregation, ASAP, driven by hydrogen, converts CO2 to starch at a rate of 22 nanomoles of CO2 per minute per milligram of total catalyst, an ~8.5-fold higher rate than starch synthesis in maize. This approach opens the way toward future chemo-biohybrid starch synthesis from CO2.”

Starch from co2 can be 8.5 times more efficient

The artificial route can produce starch from CO2 with an efficiency 8.5-fold higher than starch biosynthesis in maize, suggesting a big step towards going beyond nature. It provides a new scientific basis for creating biological systems with unprecedented functions.

The research is a first step towards industrial manufacturing of starch from CO2. From the moment the total cost of the process will become comparable with agricultural planting, this technology is expected to save more than 90% of cultivated land and freshwater resources.

In addition, it would help to prevent the negative environmental impact of pesticides and fertilizers, improve human food security and facilitate a carbon-neutral bioeconomy.