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 ◽  
...  

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.

2005 ◽  
Vol 2 (1) ◽  
pp. 3 ◽  
Author(s):  
Roger J. Francey

Environmental Context.Excessive levels of carbon dioxide are accumulating in the atmosphere, principally from burning fossil fuels. The gas is linked to the enhanced greenhouse effect and climate change, and is thus monitored carefully, along with other trace gases that reflect human activity.The rate of growth of carbon dioxide has increased gradually over the past century, and more rapidly in the last decade. Teasing out fossil emissions from changes due to wildfires and to natural exchange with plants and oceans guide global attempts in reducing emissions.


2015 ◽  
Vol 35 (02) ◽  
pp. 156 ◽  
Author(s):  
Dwi Rahayu ◽  
Winiati Pudji Rahayu ◽  
Hanifah Nuryani Jenie ◽  
Dian Herawati ◽  
Wisnu Broto ◽  
...  

was the predominant  species in producing fumonisin on agricultural products. Fumonisisn B1 (FB1) is the most abundant fumonisin in nature and the most toxic than other fumonisin. The main factors affecting the growth of   and production of fumonisin are temperature and humidity. This research aimed to assess the effect of changes in temperature and humidity on the growth of  and FB1 production on maize and soybeans medium. Maize and soybeans that have inoculated with suspension Bio 957 were incubated at 20, 30 and 40 °C with 70, 80 and 90% of humidity for 14 days. Observations of growth made by weighing the cells mass and analysis of FB1 production performed by HPLC. The results showed that the highest growth of   Bio 957 in maize and soybeans was occurred at temperature 30 °C and 90% of humidity, the cell mass weights were 904,5 and 885,5 mg per 20 g of maize and soybeans respectively. The highest concentration of FB1 in maize and soybeans were 374 and 67 pbb respectively, observed at temperature 30 °C for maize and 20 °Cfor soybeans, both at same humidity (90%). The results showed that   Bio 957 was able to grow well and produced the highest concentrations of FB1 in maize and soybeans at a temperature of 20 and 30 °C with 90% ofhumidity. At a temperature of 40 °C with 70, 80 and 90% of humidity, the growth of was not observed, therefore FB1 formation was avoided.Keywords: Fumonisin B1,  Bio 957, humidity, temperatureABSTRAKadalah spesies  yang dominan dalam memproduksi fumonisin pada produk-produk pertanian. Fumonisin B1 (FB1) merupakan fumonisin yang paling banyak ditemukan di alam dan paling toksik dibandingkan jenis fumonisin lainnya. Faktor ekstrinsik utama yang mempengaruhi pertumbuhan  dan produksi FB1 adalah suhu dan kelembaban. Penelitian ini bertujuan untuk mengkaji pengaruh suhu dan kelembabanterhadap pertumbuhan  Bio 957 dan produksi FB1 pada media jagung dan kedelai. Jagung dan kedelai yang telah diiinokulasi dengan suspensi   Bio 957 diinkubasi pada suhu 20, 30 dan 40 °C dengan kelembaban 70, 80 dan 90% selama 14 hari. Pengamatan pertumbuhan dilakukan dengan penimbangan massa sel dan analisis konsentrasi FB1 dilakukan dengan HPLC. Hasil penelitian menunjukkan bahwa pertumbuhan  Bio 957 pada jagung dan kedelai paling tinggi terjadi pada suhu 30 °C dan kelembaban 90%, berat massa selnya yaitu 904,5 dan 885,5 mg per 20 g masing-masing jagung dan kedelai. Konsentrasi FB1 paling tinggi pada jagungdan kedelai masing-masing yaitu 374 dan 67 ppb, pengamatan pada suhu 30 °C pada jagung dan 20 °C pada kedelai, keduanya pada kelembaban yang sama (90%). Hasil penelitian menunjukkan bahwa  Bio 957 mampu tumbuh dengan baik dan menghasilkan konsentrasi FB1 paling tinggi pada jagung dan kedelai pada suhu 20 dan 30 °C dengan kelembaban 90%. Pada suhu 40 °C dengan kelembaban 70, 80 dan 90%,  Bio 957 tidak menunjukkan adanya pertumbuhan, sehingga pembentukan FB1 dapat dihindari.Kata kunci: Fumonisin B1, Bio 957, kelembaban, suhu


2016 ◽  
Vol 9 (2) ◽  
pp. 205-213 ◽  
Author(s):  
N.I.P. Samsudin ◽  
N. Magan

A mycotoxigenic strain of Fusarium verticillioides previously isolated from Malaysian maize kernels and identified morphologically and molecularly was used in the present work. The objectives were (1) to screen the competitiveness of three potential antagonists isolated from Malaysian maize and three other known candidates for control of growth of F. verticillioides in vitro based on interaction scores, growth rates and hyphal area of F. verticillioides, and (2) to examine the best candidates using different spore/cell ratios on milled maize agar at different water activity conditions on relative control of fumonisin B1 (FB1). Three fungi and three bacteria (BCAs 1-6) were examined for antagonistic effects against F. verticillioides in dual-culture assays. These showed that all fungal candidates intermingled with F. verticillioides while all bacterial candidates inhibited F. verticillioides on contact or at a distance, which in turn decreased the growth rates and hyphal area of F. verticillioides significantly. Although BCA1 (Clonostachys rosea 016) did not inhibit growth or hyphal area of F. verticillioides, it was included in FB1 inhibition studies with other bacterial candidates (BCA4, Streptomyces sp. AS1; BCA5, Gram-negative rod; BCA6, Enterobacter hormaechei) because of its established mycoparasitism. The FB1 inhibition studies were conducted on milled maize agar with different spore/cell ratios of pathogen:antagonist mixtures at 0.95/0.98 water activity (aw) and 25 °C for 14 days. FB1 biosynthesis for all treatments was significantly higher at 0.95 than 0.98 aw. Of the four antagonists tested, the best was BCA1 which inhibited FB1 biosynthesis by 73 and 100% at 0.95 and 0.98 aw, respectively. BCA5 was the next best, resulting in 38 and 78% FB1 inhibition at 0.95 and 0.98 aw, respectively. The pathogen:antagonist ratios for BCA1 and BCA5 showed best results at 50:50 and 25:75. These results were discussed in context of using biocontrol agents to minimise fumonisins in maize.


2016 ◽  
Vol 121 (6) ◽  
pp. 1685-1698 ◽  
Author(s):  
A. Belbahi ◽  
I. Leguerinel ◽  
J.-M. Méot ◽  
G. Loiseau ◽  
K. Madani ◽  
...  

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.


Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 495 ◽  
Author(s):  
Kalliopi Mylona ◽  
Esther Garcia-Cela ◽  
Michael Sulyok ◽  
Angel Medina ◽  
Naresh Magan

Two garlic-derived compounds, Propyl Propane Thiosulfonate (PTS) and Propyl Propane Thiosulfinate (PTSO), were examined for their efficacy against mycotoxigenic Fusarium species (F. graminearum, F. langsethiae, F. verticillioides). The objectives were to assess the inhibitory effect of these compounds on growth and mycotoxin production in vitro, and in situ in artificially inoculated wheat, oats and maize with one isolate of each respectively, at different water activity (aw) conditions when stored for up to 20 days at 25 °C. In vitro, 200 ppm of either PTS or PTSO reduced fungal growth by 50–100% and mycotoxin production by >90% depending on species, mycotoxin and aw conditions on milled wheat, oats and maize respectively. PTS was generally more effective than PTSO. Deoxynivalenol (DON) and zearalenone (ZEN) were decreased by 50% with 80 ppm PTSO. One-hundred ppm of PTS reduced DON and ZEN production in wheat stored at 0.93 aw for 20 days, although contamination was still above the legislative limits. Contrasting effects on T-2/HT-2 toxin contamination of oats was found depending on aw, with PTS stimulating production under marginal conditions (0.93 aw), but at 0.95 aw effective control was achieved with 100 ppm. Treatment of stored maize inoculated with F. verticilliodies resulted in a stimulation of total fumonsins in most treatments. The potential use of such compounds for mycotoxin control in stored commodities is discussed.


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