scholarly journals Comparative study on the effect of temperature and water activity on Aspergillus flavus and Aspergillus carbonarius isolates growth and mycotoxin production on a chili powder medium

2020 ◽  
Vol 6 (1) ◽  
pp. 1782097
Author(s):  
Chananya Chuaysrinule ◽  
Warapa Mahakarnchanakul ◽  
Thanapoom Maneeboon
Keyword(s):  
Comparative Study ◽  
Water Activity ◽  
Aspergillus Flavus ◽  
Effect Of Temperature ◽  
Aspergillus Carbonarius ◽  
Mycotoxin Production ◽  
Powder Medium ◽  
Chili Powder

scholarly journals Effect of Temperature, Water Activity and Carbon Dioxide on Fungal Growth and Mycotoxin Production of Acclimatised Isolates of Fusarium verticillioides and F. graminearum

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 478 ◽  
Author(s):  
Ladi Peter Mshelia ◽  
Jinap Selamat ◽  
Nik Iskandar Putra Samsudin ◽  
Mohd Y. Rafii ◽  
Noor-Azira Abdul Mutalib ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Elevated Temperature ◽  
Water Activity ◽  
Fusarium Verticillioides ◽  
Fumonisin B1 ◽  
Fungal Growth ◽  
Effect Of Temperature ◽  
Mycotoxin Production ◽  
Co2 Levels

Climate change is primarily manifested by elevated temperature and carbon dioxide (CO2) levels and is projected to provide suitable cultivation grounds for pests and pathogens in the otherwise unsuitable regions. The impacts of climate change have been predicted in many parts of the world, which could threaten global food safety and food security. The aim of the present work was therefore to examine the interacting effects of water activity (aw) (0.92, 0.95, 0.98 aw), CO2 (400, 800, 1200 ppm) and temperature (30, 35 °C and 30, 33 °C for Fusarium verticillioides and F. graminearum, respectively) on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum isolated from maize. To determine fungal growth, the colony diameters were measured on days 1, 3, 5, and 7. The mycotoxins produced were quantified using a quadrupole-time-of-flight mass spectrometer (QTOF-MS) combined with ultra-high-performance liquid chromatography (UHPLC) system. For F. verticillioides, the optimum conditions for growth of fumonisin B1 (FB1), and fumonisin B2 (FB2) were 30 °C + 0.98 aw + 400 ppm CO2. These conditions were also optimum for F. graminearum growth, and zearalenone (ZEA) and deoxynivalenol (DON) production. Since 30 °C and 400 ppm CO2 were the baseline treatments, it was hence concluded that the elevated temperature and CO2 levels tested did not seem to significantly impact fungal growth and mycotoxin production of acclimatised Fusarium isolates. To the best of our knowledge thus far, the present work described for the first time the effects of simulated climate change conditions on fungal growth and mycotoxin production of acclimatised isolates of F. verticillioides and F. graminearum.

Effect of Temperature, Water Activity, and pH on Growth and Production of Ochratoxin A by Aspergillus niger and Aspergillus carbonarius from Brazilian Grapes

2014 ◽  
Vol 77 (11) ◽  
pp. 1947-1952 ◽  
Author(s):  
FABIANA REINIS FRANCA PASSAMANI ◽  
THAIS HERNANDES ◽  
NOELLY ALVES LOPES ◽  
SABRINA CARVALHO BASTOS ◽  
WILDER DOUGLAS SANTIAGO ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Water Activity ◽  
Fungal Growth ◽  
Grape Juice ◽  
Effect Of Temperature ◽  
Aspergillus Carbonarius ◽  
Optimal Conditions ◽  
Wide Range ◽  
Temperature Water

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.

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