Book of Abstracts (PDF) - International Mycological Association

IMC7 Monday August 12th Lectures
Within recent years, several techniques have been used to
study sub-generic classification in small-spored Alternaria.
Examination of 3-dimensional sporulation patterns on
standardized media has shown that there are more than
seven stable patterns of sporulation. Molecular methods,
such as RAPD-PCR, support this segregation, and
metabolite profiling has shown that sporulation patterns are
predictive of certain secondary metabolites. New methods
to utilize phenotypic features unbiased have been
developed and applied to Alternaria. Digital images of
cultures, grown on standardized media at different
temperatures, are captured and transformed into data
matrices (VideometerLab). Similarly, total HPLC
chromatograms are transformed into matrices (COW Tool).
Each matrix is then subjected to statistical analysis. Adding
other characters, such as pathogenicity or presence of
specific genes, may strengthen existing species or speciesgroups
based on morphology and reveal additional groups.
By using multivariate statistics, it is also possible to
combine several sets of different data derived from both
current and new methods (e.g. RAPD and metabolites) in
one analysis to get segregation of isolates into natural
clusters of similar taxa. The purpose of this presentation is
to introduce image analysis and multivariate statistics to
analyse chemical, physiological and molecular data,
separately and combined, in order to apply a polyphasic
and predictive strategy to Alternaria taxonomy.
72 - An assessment of research applications of Biolog
MicroPlates TM
J. Bissett * , C.A. Nolan & R. Mukagasana
Agriculture and Agri-Food Canada, Eastern Cereal and
Oilseed Research Centre, Ottawa, Ontario K1A 0C6,
Canada. - E-mail: bissettj@em.agr.ca
Biolog MicroPlates TM are employed to characterize fungal
strains based on differential assimilation of test substrates
and redox reactions in a 96-well test plate. The Biolog
method is potentially advantageous in being relatively
simple, fast and economical; and data acquisition and
identifications can be automated using a microplate reader
and applicable software. Several research applications of
the Biolog system are presented: i) the reliability of the
Biolog system as a diagnostic tool is determined for
identification of the 'green mould' disease of the
commercial mushroom caused by Trichoderma
aggressivum, ii) data from Biolog MicroPlates are
compared with ITS sequence data, and their utility assessed
in a survey of the biodiversity of Trichoderma strains from
Asia, and iii) more than 900 Trichoderma strains are
characterized using Biolog microplates, and the resulting
database used to select strains that might be exploited for
specific bioconversions. Strain level variation is more
evident with Biolog data than with DNA sequencing or
RAPD techniques, and Biolog data do not consistently
reflect phylogenies constructed from molecular data.
However, the Biolog system is an economical alternative
method for surveying biological diversity, and provides
data that complements molecular data in phylogenetic
studies. Biolog data may provide a rational for the selection
of strains for industrial applications.
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Book of Abstracts
73 - Penicillium toxins in food and feed
T. Rundberget * , I. Skaar & A. Flaaoyen
National Veterinary Institute, PO Box 8156 Dep., 0033
Oslo, Norway. - E-mail: thomas.rundberget@vetinst.no
Penicillium species appear to dominate in storage damaged
food and feed. Microbiological studies carried out at the
National Veterinary Institute have shown that under certain
conditions food may be severely infected by moulds,
especially Penicillium species, and it is important to
establish if mycotoxins are present. The Penicillium
species identified belong to the most proficient known
mycotoxin producing moulds. There are few analytical
methods available for the analyses of Penicillium toxins in
various matrices and therefore a screening method using
liquid chromatography-mass spectrometry (LC-MS) to
quantify the commercially available Penicillium toxins
roquefortine C, griseofulvin, mycophenolic acid,
verruculogen, chaetoglobosin B and penitrem A has been
developed. Penicillium crustosum Thom., is very common
in food spoilage worldwide. Several cases of intoxication
caused by toxins produced by P. crustosum have been
reported and the fungus is known to produce roqufortine C
and the penitrems A-F. Investigations of isolates of P.
crustosum, revealed the presence of penitrem A, but only
small amounts of other penitrems (B-F) when the isolates
were grown on rice. From the LC-MS traces of the rice
extracts, two major components together with penitrem A
could be seen. These two components have been isolated
and identified as two new indole-alkalod isoprenoids,
18,19-dehydrosecopenitrem A and E.
74 - Regulations in the EU for mycotoxins in foods
W.J. de Koe
Food and Public Health Consultant, Hazekamp 2, 6707
HG Wageningen, The Netherlands. - E-mail:
wjdekoe@bird.nl
The quality and safety of food may be threatened by a host
of factors, including natural toxins. Of the large spectrum
of natural toxins, mycotoxins are among the most widely
studied and raise considerable concern, because of their
ubiquity and potential deleterious effects on human and
animal health. Mycotoxins are produced by certain fungi,
which, under favorable temperature and humidity
conditions, invade a wide range of agricultural crops in the
field, and during post-harvest stages of production. In 1994
the EU started the harmonization process on
standardization of certain mycotoxins in foods after its
Scientific Committee on Food (SCF) expressed an opinion
on -in their view at that moment-, the most important
mycotoxins: aflatoxins, ochratoxin A and patulin.
Aflatoxins and ochratoxin A have been more or less
regulated now and recently certain emerging Fusarium
toxins such as deoxynivalenol have been added to the list
to be regulated soon. Estimation of the actual dietary intake