Spinach and Sunlight, the Ingredients for Converting Carbon Dioxide into Fertilizer

The expression “green technologies” is usually considered a figure of speech. Still, in the case of the new technique developed at the California Institute of Technology, it is literally like that. Mostly because they have relied on spinach to develop a technology project that converts carbon dioxide into organic plant fertilizer. Thus, in one fell swoop, global warming is mitigated, and at the same time, fertilizers are produced in an eco-friendly and sustainable way.

What they have done in this Californian technology center is to create artificial chloroplasts. Chloroplasts, as a quick reminder, are the cellular structures that allow plants and algae to carry out photosynthesis, i.e., the conversion of sunlight into chemical energy. This requires that the chlorophyll molecules inside them absorb light in the first place. The energy is stored in the form of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH), and then a set of enzymes use these chemical compounds to convert carbon dioxide into glucose. One of the main enzymes in this process is known as rubisco. Well, the researchers decided to replace rubisco with much faster enzymes, since the natural process is relatively slow. They used a combination of sixteen enzymes from nine different organisms. The resulting cycle, ten times faster, was named CETCH.

Now all that was left to develop were the artificial chloroplasts. And that’s where they used cells from the spinach leaves to extract their thylakoids. Tilacoids are small sacks that contain chlorophyll and can operate outside the plant as small sunlight processing plants. By pairing the thylakoids with the new CETCH cycle, they finally achieved the goal of the experiment: to produce glycolate, a compound used in fertilizers. Thus, technically it would be possible to create photosynthetic factories capable of producing organic fertilizers only from carbon dioxide and sunlight.  It should be remembered that the production of chemical fertilizers is behind the emission of large quantities of greenhouse gases such as methane.

Plants to produce medicines and other applications

In addition to the production of fertilizers, the new technique opens the door to other strategies. For example, it would be possible to take advantage of this type of photosynthesis to generate chemical compounds for the pharma industry. Or even develop plants that are genetically modified to absorb ten times more carbon dioxide and then be used in the production of biofuels.

It is estimated that by 2050 agricultural production will have to double to cover the food needs of the population, so sustainable initiatives like this Californian center are of vital importance. At the I’MNOVATION Hub we have covered some of the strategies that can contribute to that goal. For example, the use of wastewater to generate nitrogen. Another approach would be the use of genetically modified organisms, such as self-fertilizing cereals developed by the American MIT.  

Source: Science Mag,