Effects of temperature and incubation time on growth and ochratoxin A biosynthesis by Aspergillus carbonarius and Aspergillus ochraceus in grain-based media

Abstract Experiments were conducted to determine the culture requirements that would insure a probability of high ochratoxin production with a given isolate. Experiments at ambient temperatures (72 ± 2°F) determined the levels of the two most readily controlled variables, time and moisture content, during the growth of a high toxin-producing isolate (M298) of Aspergillus ochraceus. Tests were conducted in 2.8 L - Fernbach flasks containing 100 g shredded wheat and inoculated with spores on a transfer needle. Amounts of ochratoxin A/flask were determined by comparison against standards on TLC after chloroform extraction. Statistical analysis showed a relation between ochratoxin yield, water levels, and incubation periods. A water level of 40–70 ml/flask with an incubation period of 19-21 days at ambient temperatures should give a near to maximum yield of ochratoxin A.

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Effects of temperature and incubation time on production of ochratoxin A by black aspergilli

Research in Microbiology ◽

10.1016/j.resmic.2004.07.002 ◽

2004 ◽

Vol 155 (10) ◽

pp. 861-866 ◽

Cited By ~ 90

Author(s):

Alexandre Esteban ◽

M. Lourdes Abarca ◽

M. Rosa Bragulat ◽

F. Javier Cabañes

Keyword(s):

Ochratoxin A ◽

Incubation Time ◽

Black Aspergilli ◽

Effects Of Temperature

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Current Importance of Ochratoxin A–Producing Aspergillus spp.

Journal of Food Protection ◽

10.4315/0362-028x-64.6.903 ◽

2001 ◽

Vol 64 (6) ◽

pp. 903-906 ◽

Cited By ~ 120

Author(s):

M. L. ABARCA ◽

F. ACCENSI ◽

M. R. BRAGULAT ◽

F. J. CABAÑES

Keyword(s):

Ochratoxin A ◽

Animal Health ◽

Grape Juice ◽

Poultry Meat ◽

Aspergillus Ochraceus ◽

Aspergillus Carbonarius ◽

Penicillium Verrucosum ◽

Closely Related Species ◽

High Incidence ◽

Food Commodities

Ochratoxin A (OA) is receiving attention worldwide because of the hazard it poses to human and animal health. OA contamination of commodities, such as cereals or pork and poultry meat, is well recognized. Nevertheless, there is an increasing number of articles reporting OA contamination in other food commodities, such as coffee, beer, wine, grape juice, and milk, in the last few years. This continuous and increasing exposure to OA that humans experience is reflected in the high incidence of OA in both human blood and milk in several countries. OA was believed to be produced only by Aspergillus ochraceus and closely related species of section Circumdati and by Penicillium verrucosum; however, in the genus Aspergillus, the production of OA has been recently reported by species outside the section Circumdati. Thus, it has been clearly established as a metabolite of different species of the section Nigri, such as Aspergillus niger and Aspergillus carbonarius. OA production ability by Aspergillus spp. is more widespread than previously thought; therefore, there is the possibility that unexpected species can be new sources of this mycotoxin in their natural substrates.

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Effect of water activity, temperature and incubation time on growth and ochratoxin A production by Aspergillus niger and Aspergillus carbonarius on maize kernels

International Journal of Food Microbiology ◽

10.1016/j.ijfoodmicro.2011.03.005 ◽

2011 ◽

Vol 147 (1) ◽

pp. 53-57 ◽

Cited By ~ 44

Author(s):

L. Alborch ◽

M.R. Bragulat ◽

M.L. Abarca ◽

F.J. Cabañes

Keyword(s):

Aspergillus Niger ◽

Ochratoxin A ◽

Water Activity ◽

Incubation Time ◽

Aspergillus Carbonarius ◽

Effect Of Water ◽

Activity Temperature ◽

Maize Kernels

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Effect of Water Activity, Temperature, and Mixed Fungal Spore Interactions on Ochratoxin A Production by Aspergillus carbonarius

Journal of Food Protection ◽

10.4315/0362-028x.jfp-14-341 ◽

2015 ◽

Vol 78 (2) ◽

pp. 376-382 ◽

Cited By ~ 3

Author(s):

EFSTATHIA A. KOGKAKI ◽

PANTELIS I. NATSKOULIS ◽

GEORGE-JOHN E. NYCHAS ◽

EFSTATHIOS Z. PANAGOU

Keyword(s):

Ochratoxin A ◽

Water Activity ◽

Incubation Time ◽

Interspecific Interactions ◽

Grape Juice ◽

Fungal Spore ◽

Fungal Species ◽

Aspergillus Carbonarius ◽

Different Temperatures

The purpose of this work was to investigate the potential of two nontoxigenic Aspergillus section Nigri species (Aspergillus tubingensis and Aspergillus japonicus) to influence the in vitro ochratoxin A (OTA) production of three toxigenic Aspergillus carbonarius isolates (Ac-28, Ac-29, and Ac-33) from Greek vineyards of different geographical areas. OTA accumulation was evaluated by inoculation of 0:100, 25:75, 50:50, 75:25, and 100:0 ratios of mixed spore suspensions on a synthetic grape juice medium for up to 28 days at different temperatures (15, 20, and 25°C), water activity (aw) levels (0.95 and 0.98 aw) and incubation time (7, 14, 21, and 28 days). Results confirmed that environmental factors and fungal species had a significant effect on OTA production. Specifically, maximum OTA concentration for Ac-28 (3.21 μg g−1) and Ac-29 (7.69 μg g−1) was observed at 20°C/0.98 aw and for Ac-33 (9.13 μg g−1) at 15°C/0.95 aw, regardless of incubation time. Moreover, A. tubingensis had no significant influence on OTA concentration of all toxigenic isolates assayed, regardless of temperature, aw, and incubation time. On the other hand, the presence of A. japonicus slightly inhibited OTA production of Ac-29 and Ac-33, while for Ac-28, stimulation of OTA was observed in some cases. Overall, lower aw levels reduced OTA accumulation for Ac-28 and Ac-29, regardless of temperature, inoculum ratio, and time. On the contrary, for Ac-33, low aw increased OTA production, regardless of the investigated parameters. The importance of this study concerns the understanding of interspecific interactions on OTA diffusion by A. carbonarius in an attempt to find ways to prevent the presence of toxins in grapes and their derivatives.

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Inhibition of the growth and ochratoxin A production by Aspergillus carbonarius and Aspergillus ochraceus in vitro and in vivo through antagonistic yeasts

Food Control ◽

10.1016/j.foodcont.2014.08.042 ◽

2015 ◽

Vol 50 ◽

pp. 125-132 ◽

Cited By ~ 14

Author(s):

Chengyong Zhu ◽

Junling Shi ◽

Chunmei Jiang ◽

Yanlin Liu

Keyword(s):

Ochratoxin A ◽

Aspergillus Ochraceus ◽

Aspergillus Carbonarius

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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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