In the mycological survey of fresh salads of different vegetables, the
collected samples were tested for total counts of moulds with special
attention paid to the presence of potentially toxigenic species. The survey
also included the isolation and the identification of species, as well as the
evaluation of mycotoxin biosynthesis ability of potential producers of
ochratoxin A (OA) and sterigmatocystin (STC). Mould counts ranged from 10.0
to 4.7x102 cfu g-1. The most common moulds found in fresh salads were
Cladosporium (42.89%), Penicillium (25.78%), Aspergillus (14.67%) and
Alternaria (6.89%). C. cladosporioides (40.44%), followed by A. niger
(10.22%), P. aurantiogriseum (7.55%), A. alternata (6.89%) and Fusarium spp.
(3.11%) were the most dominating species. Other species were represented with
2.22% (Eurotium spp.), 1.56% (Botrytis spp.), 0.67% (Phoma spp.), 0.44%
(Geotrichum spp., Mucor spp., Phialophora spp.) and 0.22% (Emericella spp.,
Paecilomyces spp., Trichoderma spp., Xeromyces spp.). Twenty-two of 41
identified mould species were potentially toxigenic, which accounted for
46.18% of the total isolated population. The most frequent were the potential
producers of ochratoxin A (17.77%). Potential producers of moniliformin were
isolated in 3.11% of samples, while producers of fumonisin and STC were found
in 2.67% and 2.44% of samples, respectively. The tested isolates of OA
producers did not demonstrate the ability to biosynthetise this mycotoxins,
but two out of five isolates of A. versicolor were found to biosynthesise STC
in doses of 109.2 ng mL-1 and 56.3 ng mL-1. The obtained results indicate
that such products may threaten human health, considering that isolated
species were potentially toxigenic, while isolates of A. versicolor also
biosynthesised STS.
Introductory Chapter: Identification and Isolation of Trichoderma spp. - Their Significance in Agriculture, Human Health, Industrial and Environmental Application
