Microalgae have recently been genetically modified to serve as tiny “chemical factories” with a built-in power supply – a way to transform sunlight into compounds for affordable life-saving medication.
Researchers from the University of Copenhagen in Denmark performed the experiment to produce valuable chemicals from microalgae, creating potential flavor and fragrance compounds, bioplastics and chemotherapy drugs.
"Our study shows that it is possible to optimize the enzymatic processes in the cells using only sunlight, water and CO2 by growing them in transparent plastic bags in a greenhouse," said study author and post-doctoral researcher Thiyagarajan Gnanasekaran.
According to co-author Agnieszka Janina Zygadlo Nielsen, they hijacked a part of the energy from the microalgae’s photosynthetic structures. They redirected the energy to a genetically enhanced part of the cell that can produce various complex chemical materials, allowing them to incite the compound’s "light-driven biosynthesis."
The resulting substances, Nielsen said, are extremely pricey and difficult to create, thus produced only in small quantities in pharmaceutical plants. Cancer drug Taxol (paclitaxel), for example, is made from old yew trees, which naturally manufacture the substance in their bark.
"It is a cumbersome process which results in expensive treatments," she explained, highlighting the role of microalgae in solving the problem.
The novel method is touted sustainable and therefore more promising and cheaper than existing techniques in the long run, such as conventional yeast and E.coli cultures that require staggering amounts of sugar to function.
The water, for instance, could be replaced with water from sewage, enabling the process to run entirely on renewable energy. Gnanasekaran said industrial and city wastewater could be recycled for this purpose.
Their method, however, faces challenges of its own, particularly the microalgae using much of the captured sunlight to run their metabolic processes. It would be difficult to create massive quantities of the compounds in microalgae since they already use a huge amount of the created energy themselves, Gnanasekaran pointed out.
It is therefore sound to have the microalgae produce the helpful substances in relatively small quantities every time, he added.
The findings were published in the journal Metabolic Engineering.
Humans have gone great lengths in their search for renewable energy sources for pharmaceutical and practical uses. A separate study from a group of Chinese scientists recently presented their own new method of creating an "all-weather" solar panel, which could harness both light from the sun and raindrops as power.