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

2011 ◽  
Vol 147 (1) ◽  
pp. 53-57 ◽  
Author(s):  
L. Alborch ◽  
M.R. Bragulat ◽  
M.L. Abarca ◽  
F.J. Cabañes
2006 ◽  
Vol 108 (2) ◽  
pp. 188-195 ◽  
Author(s):  
A. Esteban ◽  
M.L. Abarca ◽  
M.R. Bragulat ◽  
F.J. Cabañes

2006 ◽  
Vol 23 (7) ◽  
pp. 634-640 ◽  
Author(s):  
A. Esteban ◽  
M.L. Abarca ◽  
M.R. Bragulat ◽  
F.J. Cabañes

2015 ◽  
Vol 78 (2) ◽  
pp. 376-382 ◽  
Author(s):  
EFSTATHIA A. KOGKAKI ◽  
PANTELIS I. NATSKOULIS ◽  
GEORGE-JOHN E. NYCHAS ◽  
EFSTATHIOS Z. PANAGOU

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.


2014 ◽  
Vol 77 (11) ◽  
pp. 1947-1952 ◽  
Author(s):  
FABIANA REINIS FRANCA PASSAMANI ◽  
THAIS HERNANDES ◽  
NOELLY ALVES LOPES ◽  
SABRINA CARVALHO BASTOS ◽  
WILDER DOUGLAS SANTIAGO ◽  
...  

The growth of ochratoxigenic fungus and the presence of ochratoxin A (OTA) in grapes and their derivatives can be caused by a wide range of physical, chemical, and biological factors. The determination of interactions between these factors and fungal species from different climatic regions is important in designing models for minimizing the risk of OTA in wine and grape juice. This study evaluated the influence of temperature, water activity (aw), and pH on the development and production of OTA in a semisynthetic grape culture medium by Aspergillus carbonarius and Aspergillus niger strains. To analyze the growth conditions and production of OTA, an experimental design was conducted using response surface methodology as a tool to assess the effects of these abiotic variables on fungal behavior. A. carbonarius showed the highest growth at temperatures from 20 to 33°C, aw between 0.95 and 0.98, and pH levels between 5 and 6.5. Similarly, for A. niger, temperatures between 24 and 37°C, aw greater than 0.95, and pH levels between 4 and 6.5 were optimal. The greatest toxin concentrations for A. carbonarius and A. niger (10 μg/g and 7.0 μg/g, respectively) were found at 15°C, aw 0.99, and pH 5.35. The lowest pH was found to contribute to greater OTA production. These results show that the evaluated fungi are able to grow and produce OTA in a wide range of temperature, aw, and pH. However, the optimal conditions for toxin production are generally different from those optimal for fungal growth. The knowledge of optimal conditions for fungal growth and production of OTA, and of the stages of cultivation in which these conditions are optimal, allows a more precise assessment of the potential risk to health from consumption of products derived from grapes.


2018 ◽  
Vol 35 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Dawit Gizachew ◽  
Yung-Chen Hsu ◽  
Barbara Szonyi ◽  
Wei-tsyi Evert Ting

Food Control ◽  
2009 ◽  
Vol 20 (8) ◽  
pp. 725-732 ◽  
Author(s):  
Anastasia E. Kapetanakou ◽  
Efstathios Z. Panagou ◽  
Maria Gialitaki ◽  
Eleftherios H. Drosinos ◽  
Panagiotis N. Skandamis

Food Control ◽  
2014 ◽  
Vol 45 ◽  
pp. 115-119 ◽  
Author(s):  
Carla Luciana Gerez ◽  
Andrea Dallagnol ◽  
Lorena Ponsone ◽  
Sofia Chulze ◽  
Graciela Font de Valdez

2010 ◽  
Vol 75 (2) ◽  
pp. M89-M97 ◽  
Author(s):  
Salma Lasram ◽  
Souheib Oueslati ◽  
Ana Valero ◽  
Sonia Marin ◽  
Abdelwahed Ghorbel ◽  
...  

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