Fungal spores bad for health but good for grasping climate change

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Environment | 15.07.2009

Deutsche Welle - Germany

http://www.dw-world.de/dw/article/0,,4488738,00.html

Fungal spores bad for health but good for grasping climate change

Großansicht des Bildes mit der Bildunterschrift: Fungi trigger allergiesEveryday

exposure to airborne fungal spores increases the risk of disease, but new

information on fungal spores could help improve understanding of the climate

system and climate change.

We're all inhaling a far greater amount and diversity of fungi floating in the

air than previously thought, according to new research conducted by the Max

Planck Institute for Chemistry and the University of Mainz.

The study shows that we breathe in between one and 10 fungal spores every time

we inhale.

" Throughout the day, we inhale seven nanograms of fungal DNA, " said Janine

Froehlich from the University of Mainz. " That is the equivalent of 10,000 times

the amount of information contained in the human genome. "

Extensive data

" Today, we have identified over 100,000 types of fungi, " she added. " According

to estimates, there are probably over 1.5 million types. "

Froehlich and Viviane Despres spent one year working on the project, filtering

air and examining the particles. DNA analysis allowed the scientists to identify

the fungal species present in the samples.

" In order to fish the different species out of the genetic soup of our samples,

we used a kind of genetic fishhook, " Froehlich said. " In contrast to earlier

studies, we used several baits for different fungal species. By doing this, we

were able to identify a significantly larger proportion of the species present. "

Relevant information

Bildunterschrift: Fungal spores help set off rainfall

Scientists are interested in the number of fungal spores in their air for three

reasons, according to Ulrich Poeschel, who headed up the study at the Max Planck

Institute for Chemistry.

" Firstly, we can use the spores to investigate whether ecosystems are being

altered by climate change, " he said. " Secondly, fungal spores play an important

role as an allergy trigger, a cause of plant damage and a disease trigger in

people, plants and animals. "

But even more interesting is the role played by fungal spores in rainfall.

" Fungal spores and other biological particles can serve as condensation and

crystallization nuclei for water drops and ice crystals, and so contribute to

the creation of clouds, fog and precipitation, " Poeschel said.

Closer investigation of the number and the properties of airborne fungal spores

could, moreover, boost understanding of these processes in climate change.

" The interactions are so complex that we are always finding new processes and

factors that we have to take into account, " said Poeschl of the link between

fungi, the biosphere and the climate.

Environmental implications

Fungal spores occur in great numbers in outdoor air, depending on geographic,

meteorological and human factors. Generally, there are lower airborne

concentrations in large towns and cities, when compared to rural and semi-rural

sites.

But until now, the abundance and diversity of airborne fungi has never been

fully explored, despite the obvious usefulness of the information. Fungal spores

account for large proportions of air particulate matter, and influence the

hydrological cycle and climate as nuclei for water droplets and ice crystals in

clouds, fog and precipitation.

Moreover, some fungi are major pathogens and allergens: Many induce allergic

responses in susceptible individuals, while allergens from fungal spores can be

potent inducers of asthma and other respiratory conditions.

Comprehensive information on the diversity of these fungi is relevant to many

areas of research such as bio-geosciences, climate and ecology, human and

veterinary medicine, industrial and human hygiene, agriculture, bioengineering

and security.

JP/UW/Ht/IDW

Editor: Sinico