Plastic bags in greenhouses using natural light

The researchers’ microalgae are cultured in large transparent plastic bags in greenhouses using natural light. Photo: Department of Plant and Environmental Sciences, University of Copenhagen

Researchers from Copenhagen Plant Science Centre at University of Copenhagen have succeeded in manipulating a strain of microalgae to form complex molecules to an unprecedented extent, they say, possibly paving the way for an efficient, inexpensive and environmentally friendly method of producing a variety of chemicals, such as pharmaceutical compounds.

“Basically, the idea is that we hijack a portion of the energy produced by the microalgae from their photosynthetic systems. By redirecting that energy to a genetically modified part of the cell capable of producing various complex chemical materials, we induce the light driven biosynthesis of these compounds,” says Post Doc Agnieszka Janina Zygadlo Nielsen who, along with colleagues Post Doc Thiyagarajan Gnanasekaran and PhD student Artur Jacek Wlodarczyk, did the research behind the study.

The researchers have modified microalgae genetically to become small chemical factories with a built-in power supply. According to the team’s study, this basically allows sunlight being transformed into everything ranging from chemotherapy or bioplastics to flavor and fragrance compounds.

The problem with many of these substances today is that they are extremely expensive and difficult to make, and therefore produced only in small quantities in the medicinal plants. “A cancer drug like Taxol for instance is made from old yew trees, which naturally produce the substance in their bark. It is a cumbersome process that results in expensive treatments. If we let the microalgae run the production this problem could be obsolete,” says Dr. Nielsen.

“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 Dr. Gnanasekaran. “Theoretically, the water could be replaced with sewage water, which could make the process run on entirely renewable energy and nutrient sources. Recycling wastewater from industry and cities to produce valuable substances would surely be positive.”