Biomedical Engineering Reference
In-Depth Information
e) Fungi producing Patulin
Patulin is a tetraketide mycotoxin produced by a variety of different
fungi, most of which are referable to the ascomycete genera
Byssochlamys
and
Eupenicillium
.
Aspergillus
species (
A. clavatus, A. giganteus, A. terreus
)
were found to be effective producers of the toxin. In foods, however,
P.
expansum
and
P. griseofulvum
are the major producers of patulin with
apples and unfermented apple juice being the main source of the toxin
in human consumption. JECFA has established a provisional maximum
tolerable daily intake for the compound of 0.4 mg/kg body weight per
day. Patulin is regulated in the European Union at levels of 50, 25 and 10
µg/kg in fruit juices and fruit nectar, solid apple products and apple-based
products for infants and young children, respectively (Regulation (EC) No
466/2001, amended by Regulation (EC) No 455/2004). The gene coding
for Isoepoxidon dehydrogenase (idh) is a key gene in patulin biosynthesis
(Sekiguchi and Gaucher 1979). Using the idh gene sequence (Fedeshko
1992), Paterson et al. (2000) set up a gene specifi c PCR for producers of
patulin. Testing of various isolates of
P. expansum
revealed general ability
of patulin production invitro and presence of the idh gene in this species.
In a follow up study, Paterson (2004) demonstrated that the idh gene
is a quite wide spread feature in the genus
Penicillium
but he also showed
presence of the gene in
Aspergillus, Paecilomyces
and
Byssochlamys spp
.
Paterson (2006) demonstrated usefulness of idh specifi c primers for the
analysis of orchard soils as critical control point in a HACCP concept
for prevention of patulin contamination in apple products. Based on the
nucleotide sequence of the polygalacturonase gene of patulin producing
P. expansum.
Marek et al. (2003) designed a pair of primers for specifi c
identifi cation and sensitive detection of
P. expansum
in pure cultures.
MICRO ARRAY BASED SYSTEMS FOR THE SIMPLE
DETECTION OF MYCOTOXINS PRODUCING
FUNGAL SPECIES
A microarray, which covers most of the known relevant mycotoxin
biosynthesis genes, has been developed (Markus Schmidt-Heydt and
Geisen 2007). The microarray carries oligonucleotides of fumonisin,
afl atoxin, ochratoxin, trichothecene (type A and B) and patulin biosynthesis
pathways. For trichothecene producing Fusaria, the biosynthesis cluster
of trichothecene producing
Fusarium sporotrichioides
(type A) and of
Gibberrella zeae
(type B, teleomorph of
F. graminearum
) were spotted. The
afl atoxin cluster carries oligonucleotides specifi c for
Aspergillus fl avus
.
The ochratoxin pattern is specifi c for ochratoxin A producing Penicillia,
