Posted by Katrina Charles, BA Media Fellow

Diatoms are eukaryotic unicelluar algae found in water. Their cell walls are made of dissolved silica and have extraordinarily intricate designs, which scientists have come up with various theories of predation and self-assembly to explain. Now scientists investigating the light properties of these organisms are hypothesising a new theory. Because of the way the diatoms can manipulate and diffract light through their cell wall, the researchers suggest that they could have evolved to maximise the potential for photosynthesis.

In a press conference today, Pete Vukusic of the University of Exeter spoke about his research into the way the diatom Coscinodiscus wailesii manipulates light. To do this, his team removed the material inside the cell and used an electron microscope to take images of the cell walls and performed “elaborate optical experiments”, including putting the cell wall on the tip of a needle, placing it in seawater and shining a lasers through it. They found that the walls also restricted the wavelengths of light that entered the diatom.

The picture below shows the highly regular patterns in the layers of the diatom cell wall. No scale is provided, but the cells are typically 230 to 370 µm.

The new hypothesis is that the nanostructure in the cell wall allows the chloroplasts within the cell better access to light needed for photosynthesis, no matter where in the cell the chloroplasts are located.

Vukusic says that understanding these structures and their manipulation of light might have applications in biomedical fields. The diatoms are cheap, easy to replicate, widely available, and may be suitable vehicle for medicines. For example, Vukusic described the possibility of coating the surfaces of diatoms so antigens attach to the surface. When an antibody attaches to the antigen it would result in a change in the light properties which can be detected optically. The results are to be published in the Journal of Materials Research in December.

Posted by Katrina Charles, BA Media Fellow

Diatoms are eukaryotic unicelluar algae found in water. Their cell walls are made of dissolved silica and have extraordinarily intricate designs, which scientists have come up with various theories of predation and self-assembly to explain. Now scientists investigating the light properties of these organisms are hypothesising a new theory. Because of the way the diatoms can manipulate and diffract light through their cell wall, the researchers suggest that they could have evolved to maximise the potential for photosynthesis.

In a press conference today, Pete Vukusic of the University of Exeter spoke about his research into the way the diatom Coscinodiscus wailesii manipulates light. To do this, his team removed the material inside the cell and used an electron microscope to take images of the cell walls and performed “elaborate optical experiments”, including putting the cell wall on the tip of a needle, placing it in seawater and shining a lasers through it. They found that the walls also restricted the wavelengths of light that entered the diatom.

The picture below shows the highly regular patterns in the layers of the diatom cell wall. No scale is provided, but the cells are typically 230 to 370 µm.

The new hypothesis is that the nanostructure in the cell wall allows the chloroplasts within the cell better access to light needed for photosynthesis, no matter where in the cell the chloroplasts are located.

Vukusic says that understanding these structures and their manipulation of light might have applications in biomedical fields. The diatoms are cheap, easy to replicate, widely available, and may be suitable vehicle for medicines. For example, Vukusic described the possibility of coating the surfaces of diatoms so antigens attach to the surface. When an antibody attaches to the antigen it would result in a change in the light properties which can be detected optically. The results are to be published in the Journal of Materials Research in December.