Comparative studies of Ochratoxin A (OTA) production by Aspergillus niger, Aspergillus ochraceus and Penicillium nordicum in Cocoa, Coffee and yeast extract sucrose agar

Aspergillus flavus NRRL 1290 and Aspergillus ochraceus NRRL 3174 were grown on a glucose-salts medium and yeast extract-sucrose broth containing the fungicide iprodione at concentrations of 0, 1,3,5, 10, 15, and 20 μg of active ingredient per ml of growth medium. Cultures were analyzed for cyclopiazonic acid, ochratoxin A, and mycelium production after 4,7, 10, 14, and 21 days of incubation at 25°C. Increasing concentrations of iprodione in the growth media resulted in greater reduction of cyclopiazonic acid, ochratoxin A, and mycelium production at the end of each incubation period. More than 50% reduction of cyclopiazonic acid, ochratoxin A, and mycelium production was observed when iprodione was added to growth media at a concentration of 5 μg/ml of medium. Higher concentrations of iprodione (10 to 20 μg/ml of growth medium) inhibited the production of cyclopiazonic acid and mycelium by A. flavus NRRL 1290 almost completely, but not the production of ochratoxin A and mycelium by A. ochraceus NRRL 3174.

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Effect of time and temperature on ochratoxin A production by Aspergillus ochraceus

Canadian Journal of Microbiology ◽

10.1139/m73-203 ◽

1973 ◽

Vol 19 (10) ◽

pp. 1259-1263 ◽

Cited By ~ 8

Author(s):

Gerald A. Sansing ◽

Norman D. Davis ◽

Urban L. Diener

Keyword(s):

Ochratoxin A ◽

Nutrient Solution ◽

Yeast Extract ◽

Aspergillus Ochraceus ◽

Shake Culture ◽

High Ph ◽

Stationary Culture ◽

Ph Values

Peak ochratoxin A production by Aspergillus ochraceus occurred at 25C after 10 and 12 days incubation on a nutrient solution of 4% sucrose and 2% yeast extract. Optimal mycelial production was at 20 and 25C at 6, 8, and 10 days incubation. High pH values of 7.6–8.2 coincided with high ochratoxin production at 25C at 8-14 days incubation. Maximal amounts of ochratoxin A were produced by A. ochraceus in 25 ml of medium/125-ml flask and 75 ml of medium/500-ml flask at 25C in stationary culture in 8 days. Ochratoxin A was not produced in this medium in shake culture.

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Carbon Catabolite Repression Gene AoCreA Regulates Morphological Development and Ochratoxin A Biosynthesis Responding to Carbon Sources in Aspergillus ochraceus

Toxins ◽

10.3390/toxins12110697 ◽

2020 ◽

Vol 12 (11) ◽

pp. 697

Author(s):

Gang Wang ◽

Yulong Wang ◽

Bolei Yang ◽

Chenxi Zhang ◽

Haiyong Zhang ◽

...

Keyword(s):

Ochratoxin A ◽

Catabolite Repression ◽

Carbon Catabolite Repression ◽

Carbon Sources ◽

Aspergillus Ochraceus ◽

Morphological Development ◽

Drastic Reduction ◽

Food And Feed ◽

Yeast Extract Sucrose ◽

Insight Into

Carbon is one of the most important nutrients for the development and secondary metabolism in fungi. CreA is the major transcriptional factor mediating carbon catabolite repression, which is employed in the utilization of carbon sources. Aspergillus ochraceus contaminates various food and feed containing different carbon sources by producing ochratoxin A (OTA). However, little is known about the function of AoCreA in regulating the morphology and OTA production of A. ochraceus. To give an insight into the mechanism of the carbon sources regulating development of A. ochraceus and OTA production, we have identified AoCreA in A. ochraceus. The homologous recombination strategy was used to generate the AoCreA deletion mutant (ΔAoCreA). We have investigated the morphology and OTA production of the wild type (WT) and ΔAoCreA of A. ochraceus with media containing different carbon sources (glucose, fructose, maltose, D-xylose, D-mannose, acetate, D-galactose, D-mannitol and lactose). ΔAoCreA showed a significant growth and conidiation defect on all media as compared with WT. Glucose and maltose were the most inducing media for OTA production by A. ochraceus, followed by sucrose and the nutrient-rich Yeast Extract Sucrose (YES) and Potato Dextrose Agar (PDA). The deletion of AoCreA led to a drastic reduction of OTA production on all kinds of media except PDA, which was supported by the expression profile of OTA biosynthetic genes. Furthermore, infection studies of ΔAoCreA on oats and pears showed the involvement of AoCreA in the pathogenicity of A. ochraceus. Thus, these results suggest that AoCreA regulates morphological development and OTA biosynthesis in response to carbon sources in A. ochraceus.

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Biochemical Characterization of Ochratoxin A-Producing Strains of the Genus Penicillium

Applied and Environmental Microbiology ◽

10.1128/aem.67.8.3630-3635.2001 ◽

2001 ◽

Vol 67 (8) ◽

pp. 3630-3635 ◽

Cited By ~ 165

Author(s):

Thomas Ostenfeld Larsen ◽

Anne Svendsen ◽

Jørn Smedsgaard

Keyword(s):

Ochratoxin A ◽

Yeast Extract ◽

Biochemical Characterization ◽

Agar Medium ◽

Meat Products ◽

Penicillium Verrucosum ◽

Array Detection ◽

Almost All ◽

Yeast Extract Sucrose

ABSTRACT In order to explore the biochemical scope of ochratoxin A-producing penicillia, we screened 48 Penicillium verrucosumisolates for the production of secondary metabolites. Fungal metabolites were analyzed by high-pressure liquid or gas chromatography coupled to diode array detection or mass spectrometry. The following metabolites were identified: ochratoxins A and B, citrinin, verrucolones, verrucines, anacines, sclerotigenin, lumpidin, fumiquinazolines, alantrypinones, daldinin D, dipodazine, penigequinolines A and B, 2-pentanone, and 2-methyl-isoborneol. By use of average linking clustering based on binary (nonvolatile) metabolite data, the 48 isolates could be grouped into two large and clearly separated groups and a small outlying group of four non-ochratoxin-producing isolates. The largest group, containing 24 isolates, mainly originating from plant sources, included the type culture of P. verrucosum. These isolates produced ochratoxin A, verrucolones, citrinin, and verrucines and had a characteristic dark brown reverse color on yeast extract-sucrose agar medium. Almost all of a group of 20 isolates mainly originating from cheese and meat products had a pale cream reverse color on yeast extract-sucrose agar medium and produced ochratoxin A, verrucolones, anacines, and sclerotigenin. This group included the former type culture of P. nordicum. We also found that P. verrucosum isolates and threeP. nordicum isolates incorporated phenylalanine into verrucine and lumpidin metabolites, a finding which could explain why those isolates produced relatively lower levels of ochratoxins than did most isolates of P. nordicum.

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In vitro effect of some fungicides used in cultivation of Capsicum spp. on growth and ochratoxin A production by Aspergillus species

World Mycotoxin Journal ◽

10.3920/wmj2012.1480 ◽

2013 ◽

Vol 6 (2) ◽

pp. 159-165

Author(s):

L. Santos ◽

S. Marín ◽

V. Sanchis ◽

A.J. Ramos

Keyword(s):

Ochratoxin A ◽

High Performance ◽

Fruit Production ◽

Aspergillus Species ◽

Aspergillus Ochraceus ◽

Fungal Load ◽

Capsicum Spp ◽

Vitro Effect ◽

Yeast Extract Sucrose

The present study aimed to assess the effect of some pre-harvest fungicides commonly used in Capsicum fruit production on growth and ochratoxin A production of three Aspergillus species found in Capsicum powder. Aspergillus tubingensis, Aspergillus ochraceus and Aspergillus westerdijkiae, previously isolated from paprika and chilli, were inoculated on yeast extract sucrose agar and paprika extract agar supplemented with different fungicides at their recommended dosage rates, and incubated at 20 and 30 °C during 7 days. Radial growth was measured after 3, 5 and 7 days and ochratoxin A production was determined by high-performance liquid chromatography with fluorescence detection on day 7. Dodine 40% and mancozeb 80% were the most effective fungicides in inhibiting growth and ochratoxin A production, regardless of the fungal strain tested or temperature conditions. Whereas the application of fungicides could be very attractive in reducing the mycotoxigenic fungal load, it can also stimulate ochratoxin A production in some cases.

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Ochratoxin A 'in vitro' biosynthesis by the Aspergillus ochraceus E'G isolate

Zbornik Matice srpske za prirodne nauke ◽

10.2298/zmspn0917069b ◽

2009 ◽

pp. 69-77 ◽

Cited By ~ 1

Author(s):

Aleksandra Bocarov-Stancic ◽

Aleksandra Miljkovic ◽

Radmila Resanovic ◽

Ksenija Nesic ◽

Vesna Jacevic ◽

...

Keyword(s):

Ochratoxin A ◽

Yeast Extract ◽

Toxin Production ◽

Aspergillus Ochraceus ◽

Submerged Cultivation ◽

Wheat Grain ◽

Liquid Media ◽

Potato Dextrose Broth ◽

Solid Substrates

This paper deals with the biosynthetic capacity for ochratoxin A (OTA) production by Aspergillus ochraceus E'G isolate derived from A. ochraceus CBS 108.08 strain, during 2007. Preliminary analysis of fungal potential for the production of OTA were performed according to the modified method of Filtenborg et al. (1983). Toxin production was tested in the following liquid media: (i) glucose-peptone-yeast extract broth (GPY - pH 5.6), (ii) potato-dextrose broth (PDB - pH 6.9), (iii) yeast extract-sucrose broth (YES - pH 6.5), and (iv) YES broth supplemented with 0.23 mg/l ZnSO4 x 5 H2O (YESZn - pH 6.5) after stationary and submerged cultivation. Dynamics of OTA biosynthesis was tested after the cultivation of A. ochraceus E'G on natural solid substrates, such as wet sterilized rice, corn and wheat grain. Cultivations were performed during different time periods (ranging from four days to few weeks) at different temperatures (ranging from 21?C to 30?C). The presence of OTA was determined as follows: (i) in liquid media according to the method of Balzer et al. (1978) modified by Bocarov-Stancic et al. (2003), and (ii) in the solid substrates according to the Serbian official methods for sampling and analyzing of fodder (Official Gazette of SFRY, No. 15/87). After the cultivation of A. ochraceus E'G isolate in liquid media, the highest yield of OTA (6.4 mg/l) was obtained after submerged cultivation in PDB (4 days, 128 rpm, 21-23?C). In the case of cultivation on solid substrates, the highest amount of OTA (800.0 mg/kg of dry matter) was recorded after several week long cultivation on wheat grain at 30?1?C.

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Effects of Potassium Sorbate on Growth and Ochratoxin Production by Aspergillus ochraceus and Penicillium Species1,2

Journal of Food Protection ◽

10.4315/0362-028x-48.2.162 ◽

1985 ◽

Vol 48 (2) ◽

pp. 162-165 ◽

Cited By ~ 13

Author(s):

LLOYD B. BULLERMAN

Keyword(s):

Yeast Extract ◽

Spore Germination ◽

Mycelial Growth ◽

The Other ◽

Aspergillus Ochraceus ◽

Potassium Sorbate ◽

Penicillium Sp ◽

Mycelial Mass ◽

Germination And Growth ◽

Yeast Extract Sucrose

Effects of potassium sorbate on growth and ochratoxin production by Aspergillus ochraceus NRRL 3174 and Penicillium sp. isolated from cheese were studied. Potassium sorbate at 0.05, 0.10 and 0.15% delayed or prevented spore germination and initiation of growth, and decreased the rate of growth of both organisms in yeast-extract sucrose (YES) broth at 12°C. However, at 25°C germination and growth of A. ochraceus was more rapid. Increasing concentrations of sorbate caused more variation in the amount of total mycelial growth of Penicillium sp. and generally resulted in a decrease in total mycelial mass. Potassium sorbate also greatly reduced or prevented production of ochratoxin by Penicillium sp. for up to 70 d at 12°C. At 0.05 and 0.10% sorbate, ochratoxin production was greatly reduced over the control, and was eliminated at 0.15%. Overall, ochratoxin production by Penicillium sp. in the presence of sorbate was very low or eliminated. On the other hand, A. ochraceus responded somewhat differently to sorbate. At 12°C, A. ochraceus was similarly inhibited by all three levels of sorbate, and did not produce ochratoxin. When incubated at 25°C, A. ochraceus grew quite readily and appeared to produce greater amounts of ochratoxin in the presence of sorbate, especially at the 0.05% level. Considerably higher levels of ochratoxin were produced at 0.05% sorbate than the control, and somewhat higher levels were obtained at 0.10 and 0.15% sorbate.

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New Ochratoxigenic Species in the Genus Aspergillus

Journal of Food Protection ◽

10.4315/0362-028x-60.12.1580 ◽

1997 ◽

Vol 60 (12) ◽

pp. 1580-1582 ◽

Cited By ~ 21

Author(s):

M. L. ABARCA ◽

M. R. BRAGULAT ◽

G. CASTELLÁ ◽

F. ACCENSI ◽

F. J. CABAÑES

Keyword(s):

Ochratoxin A ◽

Yeast Extract ◽

Yeast Extract Sucrose

A total of 176 isolates of the genus Aspergillus were screened for their ability to produce ochratoxin A in yeast extract-sucrose broth and on moistened com. Besides being produced by A. ochraceus and A. alliaceus, ochratoxin A was produced by one isolate of A. fumigatus and one of A. versicolor; species not previously reported to produce this mycotoxin.

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The Influence of NaCl and Glucose Content on Growth and Ochratoxin A Production by Aspergillus ochraceus, Aspergillus carbonarius and Penicillium nordicum

Toxins ◽

10.3390/toxins12080515 ◽

2020 ◽

Vol 12 (8) ◽

pp. 515

Author(s):

Yan Wang ◽

Hao Yan ◽

Jing Neng ◽

Jian Gao ◽

Bolei Yang ◽

...

Keyword(s):

Ochratoxin A ◽

Salt Content ◽

Meat Products ◽

Fungal Growth ◽

Aspergillus Ochraceus ◽

Aspergillus Carbonarius ◽

Mycelium Growth ◽

Glucose Content ◽

High Sugar ◽

Penicillium Nordicum

Ochratoxin A (OTA) is a nephrotoxic mycotoxin, which deserves particular attention for its widespread contamination of a variety of food and feed. Aspergillus ochraceus, Aspergillus carbonarius, and Penicillium nordicum are an important source of OTA in three different kinds of food commodities, including cereals, grape and dried fruit products, and dry-cured meat products. Deeper knowledge of OTA production and mycelium growth related to the high-sugar or NaCl-rich environments was gained in this manuscript. A. ochraceus and P. nordicum were likely to have greater growth rates in medium supplied with certain concentrations of NaCl (0–80 g/L), and the colony diameter was the largest at the salt content of 40 g/L. P. nordicum was more suitable to grow in NaCl-riched medium, the OTA production was increased to 316 ppb from 77 ppb when 20 g/L NaCl was added. The capability of OTA production was inhibited when salt content was 40 g/L and 60 g/L in A. ochraceus and P. nordicum, respectively. As the glucose content increased to 250 g/L, the capacity of mycelium growth and sporulation was increased significantly in A. ochraceus and A. carbonarius. A. carbonarius was more suitable to grow in high-sugar grape products. OTA production was significantly promoted with an added 100 g/L glucose in A. carbonarius. OTA production was inhibited when glucose content was 150 g/L and in 200 g/L in A. ochraceus and A. carbonarius, respectively. NaCl and glucose have an effect on fungal growth and OTA production, and the activation of biosynthetic genes of OtaA. These results would allow designing new strategies to prevent OTA accumulation on sugar or NaCl-riched foodstuffs and achieve the objective to manufacture cereals, dried vine fruits and dry-cured ham, free of OTA.

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Occurrence of Ochratoxin A–Producing Fungi in Raw Brazilian Coffee

Journal of Food Protection ◽

10.4315/0362-028x-64.8.1226 ◽

2001 ◽

Vol 64 (8) ◽

pp. 1226-1230 ◽

Cited By ~ 60

Author(s):

G. R. URBANO ◽

M. H. TANIWAKI ◽

M. F. de F. LEITÃO ◽

M. C. VICENTINI

Keyword(s):

Aspergillus Niger ◽

Ochratoxin A ◽

Aspergillus Ochraceus ◽

Direct Plating ◽

Production Region ◽

Agar Plug ◽

Coffee Beans ◽

High Level ◽

And Storage ◽

Positive Results

Ochratoxin A (OA)–producing fungi were identified in coffee at different stages of maturation. The toxin was quantified in coffee during terrace drying and in coffee stored in barns. By direct plating, a high level of contamination (100%) was found in the coffee beans studied, with the genus Aspergillus representing 33.2%, of which Aspergillus ochraceus and Aspergillus niger represented 10.3 and 22.9%, respectively, of the strains isolated from the coffee beans. The capacity to produce ochratoxin was determined in 155 strains of A. ochraceus and A. niger using both the agar plug method and extraction with chloroform, giving positive results for 88.1% of the A. ochraceus strains and 11.5% of the A. niger strains. Analysis for OA in the terrace and barn coffee samples showed that, independent of cultivar, year harvested, or production region, all except one of the samples analyzed showed mycotoxin levels below the limit suggested by the European Common Market (8 μg/kg), thus indicating that the problem is restricted and due to severe faults in harvesting and storage practices.

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