Introduction
Fungi are very diverse. About 1.5 million fungi species occur worldwide. They can be single celled or very complex multicellular organisms found in just about any habitat, but most live on the land – mainly in soil or on plant material. In crops, fungal diseases can lead to significant monetary loss for the farmer. Food security is a big topic. A very small number of fungi cause diseases in animals. In humans these include skin diseases such as athlete’s foot, ringworm and thrush.
Professor Cobus Visagie from the Forestry and Agricultural Biotechnology Institute at the University of Pretoria is a new generation mycologist working on the taxonomy of Aspergillus (Samson et al., 2014), Penicillium (Visagie et al., 2014), Talaromyces (Yilmaz et al., 2014) and other molds from the natural and built environment. For our ZEISS Microscopy Image Contest, he submitted a fungi image, taken with a ZEISS Axio Zoom.V16 zoom microscope. Together with Professor Bernardo Cesare’s image of an agate, his image was awarded third place.
Prof. Visagie elaborates on the image and shares some insights into his research with us:
How does this image fit into your research?
My research focus includes their biodiversity, ecology, phylogenetics, nomenclature and identification with a particular interest in taxonomically robust ecological and biodiversity studies. I thus isolate and describe many new fungal species. Even though species concepts within fungi have pretty much transitioned into a phylogenetic approach, morphology is still incredibly important. To promote this, it is my goal to produce world class images of fungi. This not only helps promote public awareness and captures the wonderful world of fungi, but also assist future morphological identifications. The tools available to do this have never been better, which is very exciting.
What was the most challenging part of acquiring an image such as this?
The image represents a synnemata (erect reproductive structure bearing compact conidiophores, which fuse together) of a new Talaromyces fungi species we found in South Africa, growing on oatmeal growth medium. These structures are relatively fragile and combined with its ‘dry’ spores are very sensitive to any kind of airflow. To capture these are a challenge as one needs to restrict the airflow as much as possible. This sample was thus prepared by cutting a block of agar out, carefully placing it on its side, and then taking ±100 extended depth of field images and stacking these together.
What about this image stands out to you?
This image made me very excited as there were very few aberrations due to structures moving. Usually one sees synnema from the top, so to capture them from the side directly from the growth medium provides a unique perspective. As a taxonomist, I believe that capturing images of fungi, creating photoplates and providing descriptions are a great way to not only express my creative side, but also another way that I can promote my work. There is something beautiful about photoplates of species. They remain forever. If I look at the first sketch made of an Aspergillus and Penicillium by Pier Antonio Micheli in 1729, I have a great appreciation for the quality of the image, especially considering the era. Because of this permanence, I want my images to stand out and be the best that they can be.
In this video, on the occasion of receiving his P-rating (future international leader) at the 2019 NRF Awards, Prof. Visagie talks about his research:
I feel privileged to be a researcher and have the support structure around me to be able to do the work that I love. I cannot help but be motivated by that.