Book of Abstracts (PDF) - International Mycological Association

IMC7 Wednesday August 14th Lectures
219 - Mycotoxins
K.F. Nielsen
The Mycology Group, BioCentrum-DTU, Technical
University of Denmark, Building 221, DK-2800 Kgs.
Lyngby, Denmark. - E-mail: kfn@biocentrum.dtu.dk
Mycotoxins produced by the building associated funga
have been proposed as one of the agents, which are
responsible for the adverse health effects, observed among
people living or working in damp and water damaged
buildings. The vehicle for exposure to mycotoxins in the
indoor environ-ment is presumable the fungal spores and
fragments of these. The quantities of thee mycotoxins
present on building materials are quite low (ng-µg/cm 2
range), and air concentrations generally so low that that
they can not be measured. Penicillia do not produce many
metabolites when growing on building materials compared
with agar-media and foods. Aspergillus versicolor is a
complex species, with at least 3 sub-groups and produces
sterigmatocystins up to 30 µg/cm 2 . However generally the
concentrations are in the ng/cm 2 range. Interestingly 4-7
alkaloids previously seen from A. ochraceus are often
produced. For Stachybotrys chartarum some evidence of
building associated mycotoxicosis exists, as it in buildings
produces high quantities of a number of metabolic families.
These includes spiriocyclic drimanes
(spirodihydrobenzofuranlactam) which are complement
inhibitors (stachybotrys lactones and lactams) and have,
fibrionolytical activity, neurotoxic effects etc. Additionally
30% of the iso-lates produces macrocyclic trichothecenes
which are highly cytotoxic to mammalian cells and are
known to give severe haematoxic effects.
220 - Biodiversity of allergenic indoor fungi colonising
dust particles and surfaces in New Zealand households
N.W. Waipara 1* , M. di Menna 2 , C. Marshall 3 , P. Howden-
Chapman 3 & J. Crane 3
1 HortResearch, Canterbury Research Centre, P.O.Box 51,
Lincoln, New Zealand. - 2 AgResearch, Ruakura Research
Centre, Private Bag 3123, Hamilton, New Zealand. -
3 Wellington School of Medicine & Health Sciences,
University of Otago, PO Box 7343, Wellington, New
Zealand. - E-mail: nwaipara@hortresearch.co.nz
Fungal species isolated from indoor environments have
been shown to produce toxic volatile organic compounds
(VOC) as well as produce allergenic spores, which can
trigger respiratory and related illnesses. A series of
mycological surveys of households were undertaken in four
climatic regions of New Zealand to determine the
biodiversity of fungi present in indoor environments, in
particular, the presence of mycotoxic and allergenic fungal
species. Fungi were isolated from vacuumed floor dust
samples and from wall surfaces using 3M Petrifilms.
Isolation results showed ubiquitous taxa, such as
Aspergillus spp., Cladosporium spp., Epicoccum nigrum,
Alternaria spp., and Penicillium spp., were frequently
obtained in both dust and surface samples. An overall
higher species diversity was obtained from dust samples
than was observed from wall surfaces, however, the
dominance of Cladosporium spp. on surfaces across all
households may have adversely reduced the sensitivity of
the Petrifilm method to detect many slow growing genera.
Significant biodiversity differences were observed between
the fungal species isolated from dust in different climatic
regions. For example, Aspergillus spp. were only dominant
in houses situated in regions with a dry warm climate.
Many households were found to be contaminated with
mycotoxic and VOC producing fungi such as Aspergillus
fumigatus, A. ochraceus, Penicillium verrucosum, and
Stachybotrys chartarum.
221 - Chiral MVOC's - a new tool for studying moulds
in building constructions?
O.-A. Braathen 1* , C. Lunder 1 , N. Schmidbauer 1 , J.
Mattsson 2 & C. Ahlén 3
1 NILU, P.O.Box 100, 2027 Kjeller, Norway. - 2 Mycoteam,
P.O.Box 5 Blindern, 0313 Oslo, Norway. - 3 SINTEF
Unimed, 7465 Trondheim, Norway. - E-mail: oab@nilu.no
MVOC-measurements can be used as a non-destructive
way to detect moulds in closed spaces in buildings. Most of
the VOCs produced by moulds can also be found in
emissions from building materials and various household
products. It is therefore hard to find MVOCs that have
microbiological activities as the only emission source. In
order to find a good tracer for moulds in sick buildings,
chiral volatile organic compounds emitted by
microbiological activity (c-MVOC) have been studied in
indoor air. For a chiral VOC-compound, there will be at
last two enantiomers ('mirror images' that have equal
chemical properties, but different physical properties).
Man-made VOCs most often occur in racemic ratio
(50:50). When there is microbiological activity involving
enzymic reactions, one of the enantiomers will dominate,
giving a non-racemic ratio (for instance 80:20 or 100:0).
Air samples were adsorbed on Tenax TA, followed by
thermal desorption and combined gas
chromatography/mass spectrometry (GC/MS) and
separation of enantiomers on suitable chromatographic
columns. In this study six of the most common moulds in
buildings with water damages were studied both at
controlled conditions in the laboratory (grown on gypsum
board and plywood) and in mould-infected buildings. This
study has shown that some chiral-MVOC can be used as a
tracer for microbiological activity (mould) in buildings.
Book of Abstracts 71