Aquirufa

Biodiversity and ecology of freshwater bacteria

Many people initially associate bacteria with diseases. However, bacteria are essential for our ecosystems. They enable the functioning of biogeochemical cycles, contribute to primary production, and perform numerous other important functions. These organisms are extremely small and occur in vast numbers in our environment. Without them, life on Earth as we know it would not be possible. Nevertheless, surprisingly little is known about the diversity and ecology of bacteria. There are likely billions of different species, but only a small fraction of them have been scientifically described so far.

The focus of the project was the bacterial genus Aquirufa. It was discovered in a previous Sparkling Science project together with students in a stream near Salzburg. These bacteria are red-pigmented, although this only becomes visible when they are cultivated in the laboratory. The scientific name “Aquirufa”, given by the students, originates from Latin and means ‘the red one from the water’. The genus comprises a diverse group of bacteria that occur in freshwater environments worldwide.

The current project “Aquirufa” pursued two main goals: First, to communicate knowledge about the world of bacteria and their importance for our ecosystems in an understandable way. Second, to scientifically investigate the genus “Aquirufa” and the associated species. A particular concern was to involve citizen scientists actively in the research over several years.

Students from eight school classes, along with other citizen scientists, including a group of divers, collected around 200 water samples from self-selected water bodies and carried out measurements. The samples were processed in the classroom as well as in the Nature and Education Centre Auenwerkstatt (Haus der Natur Salzburg) and used to establish bacterial cultures. Some students participated in summer internships at the laboratory of the Research Institute for Limnology in Mondsee, where they conducted experiments with the obtained bacterial cultures. The school classes were supported in naming newly discovered species by Professor Aharon Oren (Israel). In the second phase of the project, 130 water samples were collected together, and environmental parameters were measured directly on site. These samples were used to detect different species directly from the water sample using molecular methods.

Thanks to the dedicated participation of the citizen scientists, 15 new Aquirufa species were described in scientific publications. This work provided important new insights into their lifestyle, ecology, and distribution. Of particular interest was the finding that some of these bacteria can use sunlight to generate energy. Initial analyses of the water samples also showed that the diversity of this bacterial group is significantly greater than previously assumed. The project has therefore not only generated new knowledge but has also demonstrated that there is still a considerable need for further research.

This project is already completed.