From colony to rodlet: "A six meter long portrait of the xerophilic fungus Aspergillus restrictus decorates the hall of the Westerdijk institute."

The extreme xerophilic fungus Aspergillus restrictus is used as a model for a large artwork created out of five microscopic pictures in total measuring 80 cm by 624 cm. The artwork is printed on aluminium and located at the entrance of the Westerdijk Institute, Utrecht, The Netherlands. The first picture is made from a colony of the fungus, which has a dimension of 1 cm and the last picture shows details of ornamentation on conidia and phialides of the fungus. The first two pictures of the artwork are made using a unique method of light microscopy in which many hundreds of pictures are made at different focal depths resulting in high detail and resolution of the pictures. For three other pictures, cryo-electron scanning microscopy was used including both a conventional system for lower magnification and a field emission scanning electron microscope for high resolution micrographs. The range of magnification is, at real size, between 78 and 63,000 times. When the observer passes the artwork it acts like a virtual microscope, just by walking past it you zoom-in to the smallest possible details. This coherent increase of magnification of one fungus, with very high quality light- and electron microscopy micrographs, shows different layers of fungal organization and emergent properties. These include the occurrence of secondary outcrops of hyphae and conidiophores in a colony; the formation of a stipe on a thin aerial hyphae; the presence and formation of characteristic structures on stipes, vesicles and phialides and a continuous zone between the forming conidia and phialides.

Shaping the oral microbiota through intimate kissing.

BACKGROUND: The variation of microbial communities associated with the human body can be the cause of many factors, including the human genetic makeup, diet, age, surroundings, and sexual behavior. In this study, we investigated the effects of intimate kissing on the oral microbiota of 21 couples by self-administered questionnaires about their past kissing behavior and by the evaluation of tongue and salivary microbiota samples in a controlled kissing experiment. In addition, we quantified the number of bacteria exchanged during intimate kissing by the use of marker bacteria introduced through the intake of a probiotic yoghurt drink by one of the partners prior to a second intimate kiss. RESULTS: Similarity indices of microbial communities show that average partners have a more similar oral microbiota composition compared to unrelated individuals, with by far most pronounced similarity for communities associated with the tongue surface. An intimate kiss did not lead to a significant additional increase of the average similarity of the oral microbiota between partners. However, clear correlations were observed between the similarity indices of the salivary microbiota of couples and self-reported kiss frequencies, and the reported time passed after the latest kiss. In control experiments for bacterial transfer, we identified the probiotic Lactobacillus and Bifidobacterium marker bacteria in most kiss receivers, corresponding to an average total bacterial transfer of 80 million bacteria per intimate kiss of 10 s. CONCLUSIONS: This study indicates that a shared salivary microbiota requires a frequent and recent bacterial exchange and is therefore most pronounced in couples with relatively high intimate kiss frequencies. The microbiota on the dorsal surface of the tongue is more similar among partners than unrelated individuals, but its similarity does not clearly correlate to kissing behavior, suggesting an important role for specific selection mechanisms resulting from a shared lifestyle, environment, or genetic factors from the host. Furthermore, our findings imply that some of the collective bacteria among partners are only transiently present, while others have found a true niche on the tongue's surface allowing long-term colonization.