Photo: Iftach Yacoby
Yacoby led the study with the Arizona State University’s school of Molecular Sciences professor Kevin Redding. The study was funded jointly by the United States-Israel Binational Foundation (BSF) and National Science Foundation (NSF), and its findings were published in April in the scientific journal Energy & Environmental Science of the Royal Society of Chemistry in the United Kingdom.
At the heart of the research is the understanding that plants have particularly efficient capacities when it comes to electricity generation. “Anything green that is not dollars, but rather leaves, grass, and seaweed for example, contains solar panels that are completely identical to the panels the entire country is now building,” Yacoby explained. “They know how to take in solar radiation and make electrons flow out of it. That’s the essence of photosynthesis. Most people think of oxygen and food production, but the most basic phase of photosynthesis is the same as silicon panels in the Negev and on rooftops—taking in sunlight and generating electric current.”
The main difficulty faced by the scientists was to find the electrical current in plants and use it for other purposes. “At home, an electric current can be wired to many devices. Just plug the device into a power outlet. But when you want to do it in plants, it’s about the order of nanometers. We have no idea where to plug the plugs. That’s what we did in this study. In plant cells, we found they can be used as a socket for anything, at just a nanometer size. We have an enzyme, which is equivalent to a biological machine that can produce hydrogen. We took this enzyme, put it together so that it sits in the socket in the plant cell, which was previously only hypothetical. When he started to produce hydrogen, we proved that we had a socket for everything, though nanotermically-sized. Now we can take any plant or kelp and engineer it so that their electrical outlet can be used for production purposes,” Yacoby explained.
“If you attach an enzyme that produces hydrogen you get hydrogen, it’s the cleanest fuel that can be. There are already electric cars and bicycles with a range of 150 km that travel on hydrogen. There are many types of enzymes in nature that produce valuable substances, such as ammonia needed for the fertilizer industry and today is still produced by a very toxic and harmful method that consumes a lot of energy. We can provide a plant-based alternative for the production of materials that are made in chemical manufacturing facilities. It’s an electric platform inside a living plant cell.
“In every green colored plant is a substance called chlorophyll. This substance is the basis of the plant’s biological photovoltaic cells. We took one of these cells, incubated it, and planted a strategic hydrogenation point—the enzyme that produces hydrogen—and then we dipped it into the micro-green algae. The insertion was performed using a technology known as a cannon. It is a tiny, high-pressure helium cannon that shoots gold nanoparticles coated with DNA, a technology that has already been on the market for 20 years.”
“It was important for us to know that we hit a point that would allow for almost 100% electron supply. This slow growth has been proven, because if there was a fast growth it means that there is an electron leak and processes that we are not interested in. This is how we realized that this is a strategic site— that if you stick to some enzyme you get exclusivity on the electric current,” Yacoby said.
Despite the promising results of the study, Yacoby stressed that more work and considerable time is needed to make this into commercial development. “In order for the process to be economical, a production pace needs to be justified,” he explains. “We are not there right now. We need an improvement of between 5-10 fold to reach an economic justification for a pilot process. I believe we may be able to achieve this in the next 10 to 15 years.”
The next step is to start taking enzymes that produce other substances and try to achieve similar results, he said. “The enzyme I most dream of is one that can produce ammonia. Ammonia is the basis of the modern agricultural revolution, through which agricultural fertilizers are produced. But it is a very environmentally problematic process, the whole process can damage the ecosystem, as nitrates released into the atmosphere can produce acid rain,” Yacoby explained.
“If we can get plants to produce ammonia on their own, we don’t need to produce fertilizer at all. We can give up nitrogen fertilizer and allow plants to use nitrogen in the air without fertilizer,” he said.
“There are endless possibilities, and I’m sure this research will blow the minds of many other scientists. It will be very interesting to see what people will do with it.”
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To read more about the same research: Scientists rewire photosynthesis to fuel our future