Press release

Ancient and still a pioneer: the Blue-Green Rock Dweller is alga of the year 2017

Cross fractured Beacon sandstone from Antarctica exposing the habitat of the blue-green rock dweller (Chroococcidiopsis) as a green band underneath the surface of the rock (arrows). Photo: Burkhard Büdel, TU Kaiserslautern

Algal researchers nominated the Blue-Green Rock Dweller Chroococcidiopsis for the alga of the year 2017. The single celled organism lives inside rocks and lichens, survives extreme climatic conditions and makes hostile environments accessible – today and most likely thousands of millions of years ago as well. While doing so, it paved the way for plants and animals. The blue-green rock dweller, belonging to the cyanobacteria lives like all algae, from sunlight, and is of great interest to ecologists, biotechnologists, and desert- and space researchers. It is the favorite research subject of Prof. Dr. Burkhard Büdel from the University of Kaiserslautern, who has been investigating it for more than 30 years. He is a member of the Phycology Section of the German Society for Plant Sciences, in which the algal researches are organized and who nominate this year an alga of the year for the tenth time this year.

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Creates new habitats

“Because of its ability to take up nitrogen from the atmosphere, transferring it into its own cell substances (ammonium), and the ability to recycle phosphorus from dead cells, the blue-green rock dweller provides vitally important elements to otherwise nutrient poor habitats”, Büdel explains. Step by step, the blue-green rock dweller is followed by other organisms and thus biological soil crusts develop, even in hostile regions of the Earth. In doing so, the cyanobacterium prepares the ground for other organisms and is thus understood to be an important soil creator in the field of ecology.

Nature and laboratory

In nature Büdel recognizes the blue-green rock dweller with a microscope and confirms the field identification in the laboratory with molecular methods. For further determination and experiments he isolated and cultivated the alga that occurs in nature together with other organisms. Besides his own strain collection, he also deposited cultures at the Culture Collection of Algae at Göttingen University (SAG). This collection of microalgae is one of the largest in the world and contains more than 2500 reference strains that have been cultivated and investigated there. “Our cultures, which are also provided to other research and teaching institutes, enable all interested researchers to work with reference strains” says Dr. Maike Lorenz, curator of Göttingen’s Algal collection. “And this is necessary, even after many years, if for example new methods are available or earlier results need to be revised”.

Cyanobacteria once created the modern atmosphere

The blue-green rock dweller as can be inferred from phylogenetic studies appears to be a very ancient cyanobacterium. “From their investigations, geneticists assume that the genus evolved about two thousand million years ago. The genus resembles a very early type of cyanobacterium”, explains the Chroococcidiopsis specialist Büdel. Cyanobacteria first released oxygen in considerable amounts into the atmosphere around 2400 million years ago. Before that, the atmosphere formerly contained less than one part per thousand of oxygen. Subsequently, the oxygen content of the early atmosphere rose to the modern 20 percent. “During these two thousand million years, cyanobacteria similar to the blue-green rock dweller were the unchallenged rulers of the planet’s land surface” Büdel says. Cyanobacteria exiled the aboriginal anoxygenic bacteria and started to change the Earth decisively. Organisms that developed later on did not only profit from oxygen for respiration by the pioneering activity of cyanobacteria. The developing ozone layer became increasingly effective absorbing the detrimental UV-radiation that harmed their genetic material. This was another important precondition for the further Evolution of life on Earth.

Development assistance for other organisms

Later on cyanobacteria provided another important contribution to the further evolution of organisms. Green and red algae, bryophytes and vascular plants could make use of sunlight energy, only because they incorporated a photosynthetic cyanobacterium in ancient times. How this incorporation happened currently still is a matter of research. Without cyanobacteria, many lifeforms that we know today would not have evolved, additionally, plants and oxygen breathing animals would not exist.

Blue-green rock dweller in space research

Its resilient nature and its ability to explore new habitats, made the blue-green rock dweller an ideal candidate for NASA to colonize Mars. In the eighties and nineties of the last century NASA scientists found Chroococcidiopsis, together with four other microorganisms, ideal for transforming the red planet to an earth-like state and to enrich its atmosphere with oxygen. „Luckily, since this time the ‘Terraforming Mars‘-project has disappeared, because it was realized that it would not be good to contaminate Mars with foreign organisms“, Büdel says. However, space researchers and biotechnologists still order Chroococcidiopsis strains from the Göttingen algal growers. One of the reasons might be that cyanobacteria and algae are promising candidates for future use in closed life supporting systems for the production of oxygen in remote places.

Ecological research focus

The frugal blue-green rock dweller is, together with other cyanobacteria and algae, a research object of ecologists, taxonomists and biological soil crust researchers like Büdel. He is mostly interested in what species of the blue-green rock dweller occur in different biocrusts, how they perform photosynthesis at extreme habitats and how they grow and propagate. Büdels special focus is on how the blue-green rock dweller, and other cyanobacteria and algae, make rocks and desert soils accessible. Also, how they prepare their environment for other organisms, thus assisting with the initiation of new ecosystems and at the same time, helping to prevent desertification. In long term studies, Büdel wants to clarify if and how cyanobacteria adapt in the Arctic and Antarctic to climate change and where on our planet he might discover further hostile habitats with Chroococcidiopsis during his research activities.

joint press release of the Phycology Section and the Technische Universität Kaiserslautern