3D-printed coral better than the natural equivalent
The mutually beneficial relationship between algae and corals began million years ago and is crucial for the health of coral reefs which provide habitat for roughly 1/4 of all marine life. The competition for space and sunlight between different marine organisms has made corals adapt their structure to efficiently collect and diffuse light for use by resident microalgae. With EU funding of the BioMIC-FUEL project, scientists from the University of Cambridge successfully imitated this coral micro-ecosystem, producing microalgae up to 100 times more densely than natural corals. “Our goal was to use corals as inspiration to develop more productive techniques for growing microalgae. Unlike existing techniques that utilise a liquid growth medium and an external source shining light from above, our nature-inspired approach successfully mimics how corals trap light and distribute it internally to microalgae,” explains Daniel Wangpraseurt, marine biologist at the University of Cambridge.
3D printing providing a fertile ground for algal growth and photosynthesis
Scientists created a sophisticated 3D bioprinting technology capable of reproducing detailed coral structures that mimic the complex designs and functions of the coral’s living tissues. Their method can print structures with micrometre-scale resolution in just minutes. “Most of these cells will die if we were to use traditional extrusion-based or inkjet printing processes because these methods take hours. It would be like keeping a fish out of the water; the cells we work with will not survive if kept too long out of their culture media. Our process is high throughput and offers really fast printing speeds. It is not only compatible with algae cells, but also with human and animal cells,” outlines Wangpraseurt. Scientists developed an artificial coral tissue and skeleton with a combination of different biopolymers and hydrogels doped with cellulose nanomaterials to mimic the optical properties of living corals. Algae were also infused into the mixture. Their novel bioprinting approach was no mean feat. “Working with light materials that are generally not easy to handle was challenging. But the real success of our bioprinting approach hinged on investigating materials that although they interact weakly with light (to achieve high-resolution coral structures), they can also scatter light to algae,” explains Silvia Vignolini, from the Department of Chemistry at the University of Cambridge.
Bionic corals could provide reef relief or enhance nutrition
The newly produced hybrid living bionic corals are capable of cultivating high algal cell densities of up to 109 g/ml. Once developed further, the bioprinting technology could be utilised in efficient bioreactors that grow high-nutritional algae for use in food technologies. What’s more, the 3D-printed corals serve as a model system for studying coral reef conservation: rising ocean temperatures and acidity can upset the delicate symbiosis and cause corals to expel algae and turn white, a process called ‘coral bleaching’. “For now, we focused on improving our technology for high-end applications until we can get a high throughput. In the future, our technique might be scalable to produce high-value products at a larger scale,” Wangpraseurt concludes. Project results are published in Nature Communications. Scientists have also recently created a start-up called ‘mantaz’ that uses low-cost coral-inspired light harvesting approaches to cultivate algal bioproducts in developing countries.
Keywords
BioMIC-FUEL, microalgae, bioprinting, 3D-printed coral, symbiosis, coral reef, coral bleaching
