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S C HW E R P U N K T 35 03 | LICHT GEDANKEN Contact Prof. Dr Maria Mittag, Dr Severin Sasso Matthias Schleiden Institute of Genetics, Bioinformatics and Molecular Botany Am Planetarium 1, D-07743 Jena, Germany Phone: +49 36 41 9-49 201 +49 36 41 9-49 475 Email: M.Mittag@uni-jena.de severin.sasso@uni-jena.de www.botanik.uni-jena.de Original Publication Antagonistic bacteria disrupt calcium homeostasis and immobilize algal cells. Nature Communications (2017), DOI : 10.1038/s41467-017-01547-8 of calcium with the help of the lumine- scence,« explains Prof. Mittag, Professor for General Botany. In some cases, the changes in the calcium lead to changes in the direction of movement, for exam- ple after light perception. In other cases, for example after the bacterial attack, they cause the loss of the flagella. Researching the »chemical language« between microorganisms and their environment In addition, the teams were able to show that the bacteria can tap the algae and use them as a nutrient source if they are lacking in nutrients. »We have evi- dence that other substances from the toxic cocktail released by the bacteria also play a role in this,« says Maria Mit- tag. Her team, once again in coopera- tion with the teams of Prof. Hertweck und Dr Sasso, now also wants to track down these substances, in order to gain a precise understanding of this chemical communication between algae and bac- teria. Numerous research groups have dedicated their efforts to studying the »chemical language« between microor- ganisms and their environment as part of the Collaborative Research Centre »ChemBioSys«. Microbial species com- munities occur in virtually every habitat on Earth. »In these communities, both the species composition and the inter- relations between individual organisms of one or more species are regulated by chemical mediators,« says Prof. Hert- weck, who is the speaker for the Collab- orative Research Centre and head of the Biomolecular Chemistry department at HKI. The aim of the interdisciplinary research partnership is to explain the fundamen- tal control mechanisms in complex bio- systems, which affect the whole of life on Earth. »We want to understand the mechanisms through which the micro- bial community structures are formed and their diversity maintained.« They are important, because essentials of life—not least for human beings—de- pend on them, for example food or air. This is also true of microalgae such as Chlamydomonas reinhardtii . Such photo- synthetic microorganisms (phytoplank- ton) make a contribution of about 50 per cent towards fixing the greenhouse gas carbon dioxide and, as a byproduct of photosynthesis, they supply the oxygen that is essential for our survival. In addition, microalgae, which are found in fresh water, wet soils or the world’s seas and oceans, represent an important basis for food chains, especially in aquatic systems. For exam- ple, zooplankton in the oceans feed on the algae and together they provide food for crustaceans, which in turn are eaten by fish, before these are eaten by bigger fish or caught by humans. »In view of the huge significance of microalgae for human life, we still know astonishingly little about the fundamental elements and the interactions in their microscopic world,« says Prof. Mittag. Research team head by Prof. Dr Maria Mittag (back row left) and Dr Severin Sasso (back row right): David Carrasco Flores, Dr María García-Altares (HKI), Prasad Aiyar und Daniel Schaeme (front row from left). F E AT U R E