Could the answer to global food insecurity and the climate crisis be found in a microscopic organism? Algae, often overlooked and underappreciated, are emerging as a powerful resource in the quest for sustainable solutions. Researchers have discovered a way to harness algae’s ability to store starch, offering a potential breakthrough for both food production and environmental protection.
The overlooked power of starch
Starch plays a central role in our lives. It provides most of the calories consumed globally and is found in everything from bread and rice to pasta and potatoes. But starch isn’t just about food. It also forms the base of many products used in industry, including fuels, cosmetics, animal feed, adhesives and pharmaceuticals (Figure1).
Currently, this vital resource is sourced primarily from crops like corn and wheat. However, as land becomes more scarce and environmental pressures mount, the competition between food and industrial use continues to grow. There is an urgent need for alternative sources of starch that don’t rely on arable land or freshwater.
Starch also plays a role in food storage and preservation. It helps to maintain the texture and shelf life of many processed foods. Its widespread use makes it a critical ingredient in the global food economy. This makes the need for scalable and sustainable starch sources even more urgent, especially as global demand increases.
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Why algae may be the answer
Algae are microscopic organisms that carry out photosynthesis, just like plants (Figure 2). But unlike traditional crops, algae can grow rapidly in water, even in non-arable environments. They do not require fertile soil, and they can be cultivated in controlled conditions.
What makes algae particularly promising is their ability to store excess energy in the form of starch. Many algae can accumulate significant amounts of starch within their cells. And because they grow quickly and don’t compete with food crops, they represent an efficient and eco-friendly alternative.
Some algae species also thrive in brackish or wastewater environments, allowing for cultivation without drawing from freshwater supplies. This characteristic gives them a significant edge in sustainability compared to conventional crops that rely on irrigation.
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The discovery of a molecular switch
Researchers led by Dr Sousuke Imamura have uncovered the molecular mechanism that controls starch storage in algae. The key lies in a protein called TOR, which stands for “Target of Rapamycin.” This protein is found in many organisms and plays a role in how cells respond to nutrients.
In algae, TOR acts as a kind of switch. When it is active, starch production is halted. But when TOR is turned off, starch begins to build up quickly. In laboratory experiments, blocking TOR in the alga Cyanidioschyzon merolae caused a tenfold increase in stored starch. Similar results were observed in another species, Chlamydomonas reinhardtii. This discovery offers a way to trigger starch accumulation at will, making it easier to manage and optimise production.
Inside the algae: What changes?
The team looked closely at how TOR influences the algae’s internal processes. They found that it affects two important proteins: GLG1 and GWD. GLG1 is involved in starch synthesis, while GWD is involved in starch degradation.
When TOR is inactive, GLG1 becomes more active and GWD less active. This means the algae produce more starch while breaking down less of it (Figure 3). The researchers discovered that this shift depends on changes to just one amino acid in each protein. These small adjustments act like on-off switches, telling the cell when to build up starch.
This level of control demonstrates how even the tiniest molecular changes can lead to large-scale biological effects. By manipulating this single point of regulation, scientists have identified a powerful tool for reprogramming cellular behaviour.
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Implications for other plants
This mechanism isn’t unique to algae. The same proteins TOR, GLG1 and GWD are also found in land plants. That means the molecular switch discovered in algae could also work in crops like rice, wheat or maize.
If scientists can apply this knowledge to traditional crops, it could lead to higher starch yields and better resource efficiency. This has huge implications for agriculture, especially in areas facing land or water shortages. This could also benefit farmers in regions where conventional fertilisers and irrigation systems are too costly or unavailable. By enhancing the internal regulation of starch production, crops could become more productive under stress conditions.
From food to fuel: The uses of algae-based starch
Starch produced by algae could serve a wide range of purposes. It can be used in food, of course, but also in bioplastics, animal feed and renewable fuels like bioethanol. These uses are especially attractive because algae do not require the same inputs as traditional crops.
Algae also absorb carbon dioxide during photosynthesis. That makes them useful for reducing greenhouse gases, especially if grown on a large scale. In this way, algae offer a double benefit: a new source of essential resources and a way to help manage emissions.
As industries look for greener alternatives to petrochemical products, algae-based starch could meet demand for sustainable materials. It is biodegradable, renewable and can be produced with relatively low environmental impact.
Towards commercial applications
Dr Imamura’s research group is now planning to boost starch production even further. By enhancing GLG1 and suppressing GWD, they hope to make algae more efficient at storing starch. This could make commercial production more viable.
Future experiments will test whether these findings apply outside laboratory settings. Researchers want to know if the TOR switch can be used reliably in algae farms and whether it works across different species and environments. These studies will help determine how scalable and practical algae-based starch production really is.
Investment in biotechnological research and infrastructure will be key to translating these scientific findings into real-world solutions. Collaborations between academic institutions, governments and private companies could speed up the development of algae-based industries.
A new direction for sustainability
This research is part of a broader shift towards using biological systems to solve environmental and social problems. Algae are an excellent example of how small organisms can have a large impact. By tapping into their natural abilities and guiding them with scientific insight, researchers are opening new paths towards sustainability.
The TOR switch offers more than just a tool for starch production. It highlights the value of exploring cellular mechanisms in simple organisms to address complex global challenges. The lessons learned from algae may well influence broader strategies in biotechnology, from crop engineering to bioenergy production.
What lies ahead?
There is still work to be done, but the potential is clear. If scientists can develop reliable systems to cultivate algae and control their starch output, it could revolutionise the way we produce both food and materials.
This approach could ease pressure on farmland, reduce the carbon footprint of industrial production, and offer more resilient food sources in a changing climate. The hope is that algae, long seen as little more than pond scum, will become a cornerstone of sustainable development. Could these tiny organisms hold the key to nourishing both people and the planet?
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Journal reference
Komiya, S., Pancha, I., Shima, H., Igarashi, K., Tanaka, K., & Imamura, S. (2025). Target of rapamycin signaling regulates starch degradation via α-glucan water dikinase in a unicellular red alga. Plant Physiology, 197(4), kiaf106. https://doi.org/10.1093/plphys/kiaf106
