The biology laboratory at the Fraunhofer Institute for Building Physics IBP has its own special garden. But the specimens that grow and flourish here would not be particularly welcome in the average greenhouse. For some ten years now, the team of biologists led by Dr. Wolfgang Hofbauer has been nurturing algae, mold fungi and other microorganisms. It is not the only collection of this kind in Germany, but it is nonetheless unique in two major respects. The first is its unusually broad scope, for this collection contains both photosynthetically active organisms (algae) and organisms that do not photosynthesize (fungi and bacteria). Secondly, it is devoted to microorganisms that perform the same type of "work", namely invading and attacking building components. The organisms were originally isolated from wild populations found growing in and on buildings being investigated for microbial damage. Today’s descendants of these algae and fungi have been allowed to continue exercising their destructive tendencies in the biology laboratory and outdoor test facilities operated by Fraunhofer IBP in Holzkirchen – albeit under the scientists’ watchful eye.
The laboratory’s microorganisms are used for various purposes including a wide range of tests and experimental studies. Dr. Wolfgang Hofbauer and his team are, for example, conducting research on smart materials that are resistant to microbial growth, and they regularly perform biological tests on building materials according to official standards and customers’ requirements or using proprietary methods.
The most unusual find that Dr. Wolfgang Hofbauer can recall is a fungal spore that he still remembers not so much because of its rarity but on account of the place where it was found. "We had been asked to examine a swimming pool that had problems with mold infestation. In one of our samples, we discovered a single spore of a fungus that normally only grows in forests, on very rotten tree trunks. A single spore can hardly be classed as an infestation, but we kept it anyway," says Dr. Wolfgang Hofbauer. In fact, he not only kept it, he let it grow in the laboratory, "because it develops in such beautiful patterns that look like deer antlers".
Reading tips for more information on building biology (in German only):
Biological infestation of building facades – how high is the risk of penetration to the interior?
Mold growing behind the wardrobe – the strange habitats of Eurotium rubrum
Comparative tests of molds growing on the surface of different building materials based on isopleth maps