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Title: Ochratoxin A production by Penicillium thymicola

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Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
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Grant/Contract Number:
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Fungal Biology
Additional Journal Information:
Journal Volume: 120; Journal Issue: 8; Related Information: CHORUS Timestamp: 2017-10-04 16:36:03; Journal ID: ISSN 1878-6146
Country of Publication:

Citation Formats

Nguyen, Hai D. T., McMullin, David R., Ponomareva, Ekaterina, Riley, Robert, Pomraning, Kyle R., Baker, Scott E., and Seifert, Keith A. Ochratoxin A production by Penicillium thymicola. Netherlands: N. p., 2016. Web. doi:10.1016/j.funbio.2016.04.002.
Nguyen, Hai D. T., McMullin, David R., Ponomareva, Ekaterina, Riley, Robert, Pomraning, Kyle R., Baker, Scott E., & Seifert, Keith A. Ochratoxin A production by Penicillium thymicola. Netherlands. doi:10.1016/j.funbio.2016.04.002.
Nguyen, Hai D. T., McMullin, David R., Ponomareva, Ekaterina, Riley, Robert, Pomraning, Kyle R., Baker, Scott E., and Seifert, Keith A. Mon . "Ochratoxin A production by Penicillium thymicola". Netherlands. doi:10.1016/j.funbio.2016.04.002.
title = {Ochratoxin A production by Penicillium thymicola},
author = {Nguyen, Hai D. T. and McMullin, David R. and Ponomareva, Ekaterina and Riley, Robert and Pomraning, Kyle R. and Baker, Scott E. and Seifert, Keith A.},
abstractNote = {},
doi = {10.1016/j.funbio.2016.04.002},
journal = {Fungal Biology},
number = 8,
volume = 120,
place = {Netherlands},
year = {Mon Aug 01 00:00:00 EDT 2016},
month = {Mon Aug 01 00:00:00 EDT 2016}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1016/j.funbio.2016.04.002

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Cited by: 3works
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Web of Science

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  • Spores from the toxigenic organism Aspergillus ochraceus NRRL-3174 were exposed to specific levels of gamma irradiation and then allowed to germinate on selected media. Increases in ochratoxin A production by irradiated, compared to non-irradiated, spores were observed after inoculation of spores onto a cracked red wheat or into a synthetic liquid medium. Variations in daily ochratoxin production were also observed for control and irradiated spore-derived cultures developing on both media, with maximum toxin production varying from 7 to 11 days of incubation. The most notable increases in ochratoxin A production occurred from cultures developing from spores having been irradiated withmore » 10, 25, or 50 krad. Exposures to 400 or 600 krad resulted in complete inhibition of spore germination and, consequently, no ochratoxin production. Of the two substrates used, wheat and synthetic, the quantities of ochratoxin A produced were significantly lower in the synthetic media than on the natural substrate. Higher and more rapid toxin production occurred from spores having been irradiated with 10, 25, 50, and 100 krad than occurred from the non-irradiated control spores when grown on synthetic media. Cultures derived from spores having been exposed to 10, 25, and 50 krad produced significantly higher levels of ochratoxin A after 8 days of incubation on natural substrate than did the controls. Analysis of variance revealed that substrate, length of incubation, as well as irradiation levels all affected the time required to produce maximum levels of ochratoxin A.« less
  • The radiation sensitivity and the toxigenic potential of conidiospores of the fungus Aspergillus alutaceus var alutaceus were determined after irradiation with {sup 60}Co gamma rays and high-energy electrons. Over the pH range of 3.6 to 8.8, the doses required for a 1 log{sup 10} reduction in viability based on the exponential portion of the survival curve ranged from 0.21 to 0.22 kGy, with extrapolation numbers (extrapolation of the exponential portion of the survival curve to zero dose) of 1.01 to 1.33, for electron irradiation, and from 0.24 to 0.27 kGy, with extrapolation numbers of 2.26 to 5.13, for gamma irradiation.more » Nonsterile barley that was inoculated with conidia of the fungus and then irradiated with either electrons or gamma rays and incubated for prolonged periods at 28C and at a moisture content of 25% produced less ochratoxin levels compared with unirradiated controls. In these experiments, inoculation with 10{sup 2} spores per g produced greater radiation-induced enhancement than inoculation with 10{sup 5} spores per g. There was no radiation-induced enhancement when the barley was surface sterilized by chemical means prior to irradiation. These results are consistent with the hypothesis that a reduction in the competing microbial flora by irradiation is responsible for the enhanced mycotoxin production observed when nonsterile barley is inoculated with the toxigenic fungus A. alutaceus var. alutaceus after irradiation.« less
  • The present studies, using Asperigillus alutaceus var. alutaceus Berkeley et Curtis (formerly A. ochraceus Wilhelm) NRRL 3174 along with three other wild-type strains, were undertaken in an attempt to understand the effects of irradiation and other treatments on mycotoxin production in grain. Bedford barley was inoculated with spores of NRRL 3174, gamma irradiated, and incubated at 28C and 25% moisture. After 10 days of incubation, two colony types, ocher (parental) and yellow (variant), were isolated from the grain. Further culturing of the yellow variant resulted in the spontaneous appearance of a white variant that exhibited greatly enhanced fluorescence under UVmore » light. In subsequent work, we have also isolated variants producing a soluble red pigment. In addition, in model experiments involving irradiation (1 kGy) of pure cultures, induction frequencies ranging between 2 and 4% (survival basis) were observed for the yellow and red variants. Inoculation of these variants into wheat and incubation for 14 days at 28C and 32% moisture resulted in ochratoxin A production in the relative amounts of 0.09:1:4.6:9.3 for the red, ocher (parental), yellow, and white variants, respectively. Additional characteristics of these isolates are described. Confirmation that the white high-ochratoxin-A-producing variants were derived from the parental strain was demonstrated by obtaining revertant sectors in monoclonal cultures of the variants.« less
  • The mycotoxin ochratoxin A (OTA), an ubiquitous contaminant of food products endowed with a wide spectrum of toxicity, affects several functions of mononuclear leukocytes. Monocytes/macrophages play a major role in fibrin accumulation associated with immune-inflammatory processes through the production of tissue factor (TF) and plasminogen activator inhibitor 2 (PAI-2). We studied the effect of OTA on TF and PAI-2 production by human blood mononuclear cells (MNC). The cells were incubated for 3 or 18 h at 37 deg. C with non toxic OTA concentrations in the absence and in the presence of lipopolysaccharide (LPS) or other inflammatory agents. TF activitymore » was measured by a one-stage clotting test. Antigen assays were performed by specific ELISAs in cell extracts or conditioned media and specific mRNAs were assessed by RT-PCR. OTA had no direct effect on TF and PAI-2 production by MNC. However, OTA caused a dose-dependent reduction in LPS-induced TF (activity, antigen and mRNA) and PAI-2 (antigen and mRNA) production with > 85% inhibition at 1 {mu}g/ml. Similar results were obtained when monocyte-enriched preparations were used instead of MNC. TF production was also impaired by OTA (1 {mu}g/ml) when MNC were stimulated with phorbol myristate acetate (98% inhibition), IL-1{beta} (83%) or TNF-{alpha} (62%). The inhibition of TF and PAI-2 induction might represent a hitherto unrecognized mechanism whereby OTA exerts immunosuppressant activity.« less