scholarly journals Efficacy of metabolites of a Streptomyces strain (AS1) to control growth and mycotoxin production by Penicillium verrucosum, Fusarium verticillioides and Aspergillus fumigatus in culture

2020 ◽  
Vol 36 (2) ◽  
pp. 225-234
Author(s):  
A. Mohd Danial ◽  
A. Medina ◽  
M. Sulyok ◽  
N. Magan
Keyword(s):  
Aspergillus Fumigatus ◽  
Fusarium Verticillioides ◽  
Penicillium Verrucosum ◽  
Streptomyces Strain ◽  
Mycotoxin Production ◽  
Control Growth

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.

scholarly journals Integrating gene expression, ecology and mycotoxin production by Fusarium and Aspergillus species in relation to interacting environmental factors

2016 ◽  
Vol 9 (5) ◽  
pp. 673-684 ◽  
Author(s):  
N. Magan ◽  
A. Medina
Keyword(s):  
Environmental Factors ◽  
Fusarium Verticillioides ◽  
Fusarium Culmorum ◽  
Toxin Production ◽  
Stress Conditions ◽  
Toxin Gene ◽  
Biosynthetic Genes ◽  
Mycotoxin Production ◽  
Extreme Stress ◽  
Temperature Conditions

Environmental factors, such as water availability (water activity, aw), temperature and their interactions, have a significant impact on the life cycle of mycotoxigenic fungi. Growth and mycotoxin production are influenced by these interacting factors resulting in a broader range of aw × temperature conditions for germination, than growth or mycotoxin production. The biosynthetic genes are mostly clustered together and by using microarrays with sub-arrays for specific mycotoxins, such as trichothecenes, fumonisins and aflatoxins it has been possible to examine the relationship between interacting aw × temperature conditions on growth, toxin gene cluster expression and relate these to phenotypic toxin production. The data for groups of biosynthetic genes (Fusarium culmorum/Fusarium graminearum; Fusarium verticillioides; Aspergillus flavus) were integrated with data on growth and mycotoxin production under different aw × temperature conditions using a mixed growth model. This was used to correlate these factors and predict toxin levels which may be produced under different abiotic stress conditions. Indeed, the relative importance of the different genes could be examined using ternary diagrams of the relative expression of 3 genes at a time in relation to aw, temperature and mycotoxin production to identify the most important relationships. The effect of three-way interacting environmental factors representative of climate change (CC) scenarios (water stress × temperature (+2-4 °C) × elevated CO2 (350-400 vs 650 and 1000 ppm) on growth and mycotoxin production by A. flavus and by species of the Aspergillus section Circumdati and section Nigri have been determined. These studies on maize grain and coffee, respectively, suggest that while growth may not be significantly affected, mycotoxin production may be stimulated by CC factors. This approach to integrate such data sets and model the relationships could be a powerful tool for predicting the relative toxin production under extreme stress conditions, including CC scenarios.

scholarly journals Inhibition of Mycotoxigenic Fungi in Different Vegetable Matrices by Extracts of Trichoderma Species

2021 ◽  
Vol 7 (6) ◽  
pp. 445
Author(s):  
Claudia Stracquadanio ◽  
Carlos Luz ◽  
Federico La Spada ◽  
Giuseppe Meca ◽  
Santa Olga Cacciola
Keyword(s):  
Fusarium Verticillioides ◽  
Economic Losses ◽  
Dependent Manner ◽  
Trichoderma Atroviride ◽  
Penicillium Verrucosum ◽  
Time Intervals ◽  
Trichoderma Species ◽  
Mycotoxigenic Fungi ◽  
Dose Dependent ◽  
Chemical Fungicides

Post-harvest fungal diseases of plant products are a serious concern leading to economic losses and health risks. Moreover, the use of synthetic chemical fungicides to prevent these diseases is limited due to toxic residues. This study aimed at determining the effective dose of extracts of Trichoderma asperellum IMI393899 (TE1) and Trichoderma atroviride TS (TE2) in inhibiting the contamination by mycotoxigenic fungi on different plant matrices. Extracts were tested on tomatoes contaminated by Fusarium verticillioides and Fusarium graminearum, wheat contaminated by Penicillium verrucosum and maize contaminated by Aspergillus flavus. The efficacy of extracts was evaluated at two time intervals after treatment, 4 and 11 days for tomato, and 10 and 20 days for both wheat and maize. Both extracts showed a significant inhibitory activity on mycotoxigenic pathogens and significantly reduced Log CFU/g compared to the control. Moreover, the extracts reduced mycotoxin production in a dose dependent manner and with a long-lasting effect. The ochratoxin A was reduced by both extracts but only the extract TE2 was effective in reducing aflatoxins, whereas TE1 treatment increased their synthesis.

scholarly journals Influences of Methodological Variables on Susceptibility Testing of Caspofungin against Candida Species and Aspergillus fumigatus

2003 ◽  
Vol 47 (7) ◽  
pp. 2100-2107 ◽  
Author(s):  
C. Bartizal ◽  
F. C. Odds
Keyword(s):  
Aspergillus Fumigatus ◽  
Incubation Time ◽  
Susceptibility Testing ◽  
Inhibitory Concentration ◽  
Process Variable ◽  
Growth Conditions ◽  
Medium Composition ◽  
Growth Yields ◽  
Control Growth ◽  
Common Process

ABSTRACT The influences of test variables on the outcome of susceptibility testing with caspofungin were tested with isolates of Candida spp. and Aspergillus fumigatus. Among six growth conditions tested with a range of inoculum sizes, the highest control growth yields were obtained in Sabouraud broth for all fungi, followed by RPMI 1640 (pH 7) for Candida spp. and antibiotic medium 3 (AM3) for A. fumigatus. RPMI 1640 gave unacceptably low growth yields with A. fumigatus. The caspofungin MICs under these various conditions ranged over more than 4 twofold dilutions for 7 of 16 fungi tested when a 50% inhibition (50% inhibitory concentration [IC50]) endpoint was used and for 12 of 16 fungi tested when an 80% inhibition (IC80) endpoint was used. A multifactorial design to study the influences of six test variables on control growth and the MIC showed that, for 14 isolates of Candida spp., the glucose concentration and the medium composition were the most common factors significantly influencing both control growth yields and the MIC. For eight A. fumigatus isolates, incubation time (24 versus 48 h) and temperature (30 versus 35°C) significantly affected control optical density (OD) values, while growth medium (AM3 versus Sabouraud broth) was the most common process variable affecting the MICs. Tests with AM3 from three suppliers showed significant variations in control OD values related to supplier, but IC50s fell within a 2- or 3-dilution range for 19 (86%) of the 22 isolates tested. We recommend that, at present, AM3 is superior to RPMI 1640 for testing of the susceptibilities of both yeasts and filamentous fungi to caspofungin and that a minimum incubation time of 48 h is necessary to test A. fumigatus adequately.

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