Back in 2021 cyanobacteria from cave environments in Spain got my attention due to some fascinating microscopic images presented by Antonio Guillen aka proyectoagua on instagram. We got connected and this talented colleague soon collected biofilms from the caves hosted by Astroland Agency for me. This was the beginning of a new love for me: exploring the cyanobacterial diversity of cave habitats.
It took me more than a year of constant work in the lab in order to get about 40 cyanobacterial isolates from this initial material. In between I could take some spectacular images of the different isolates and we also got a lot of full 16S rRNA gene sequences so that I can pinpoint the identity of these strains. Among them wehre some really rare taxa such as Scytonema sensu stricto, Geitleria calcarea, Timaviella sp., Chalicogloea cavernicola and Gloeobacter sp. All of these and many more made it to be adapted to the cave environment. Sure, constant temperatures and humidity levels sound fantastic for cyanos but what about light? There is no light in caves, right? No.
Red light, a specific quality of light that we humans can't see with our eyes reaches deep into the caves - as deep as 60 meter. Some of these cyanobacteria produce the pigment Chlorophyll f which allows them to exactly use this red light as an energy source for their photosynthetic activity.
Highly intrigued by these cave cyanobacteria I decided to visit the cave in Cantabria by myself together with my colleagues Michael Lakatos, Antonio Guillen, Astroland Agency and Dennis Nürnberg (Free University of Berlin) - the Chlorophyll f expert.
All together we were fascinated by all these walls covered overe and over with cyanobacteria mucilage. Different colors, shapes and textures created by the cyanobacteria waited for us and of course we sampled all of it with a lot of care. Now, about 60 additional cultures are growing in our labs and we can't wait to dive deeper into this amazing world.