Browsing by Author "Medina Vaya, Angel"

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    Data for "The influence of different abiotic conditions on the concentrations of free and conjugated (masked) deoxynivalenol and zearalenone in stored wheat"
    (Cranfield University, 2024-02-09 16:10) Oluwakayode, Abimbola; Greer, brett; Meneely, Julie; He, Qiqi; Sulyok, Michael; Krska, Rudolf; Medina Vaya, Angel
    This study aims to examine the impact of storage conditions of water activities 0.93, 0.95, 0.98 aw and temperature 20-25 °C on (a) the concentrations of DON and ZEN and their respective glucosides/conjugates and (b) the concentrations of emerging mycotoxins in both naturally contaminated and irradiated wheat grains inoculated with Fusarium graminearum to ascertain any potential increases in toxicity in the wheat grains.
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    Data underpinning "Interacting climate change environmental factors effects on Fusarium langsethiae growth, expression of Tri genes and T-2/HT-2 mycotoxin production on oat-based media and in stored oats"
    (Cranfield University, 2019-08-21 09:08) Verheecke, Carol; Magan, Naresh; Diez, Lucia; renaud, justin; Sumarah, Mark; Medina Vaya, Angel
    The objectives of this study were to investigate the impact that interactions between key climate change (CC) related environmental factors of temperature (20, 25, 30°C), water activity (aw; 0.995, 0.98) and CO2 exposure (400, 1000 ppm) may have on (a) growth, (b) gene expression of biosynthetic toxin genes (Tri5, Tri6, Tri16), and (c) phenotypic T-2/HT-2 production by Fusarium langsethiae on oat-based agar medium and in stored oats. Fungal growth was optimum at 25°C and 0.995 aw and reduced significantly at 30°C and intermediate stress (0.98 aw, elevated CO2 (1000 ppm) exposure by approx. 4-fold. Lag phases prior to growth paralleled these results with the longest lag phase in this treatment (24 hrs). On oat-based medium, the relative Tri5 gene expression was increased in elevated CO2 conditions. The expression of both the Tri6 and Tri16 genes was reduced when compared to control (20°C, 0.995 aw, 400 ppm), especially in elevated CO2 conditions. In stored oats, the Tri5 gene expression was reduced in all conditions except at 30°C, 0.98 aw, elevated CO2 where there was a significant (5.3-fold) increase. The expression of the Tri6 was slightly over-expressed in elevated CO2 and the Tri16 gene was upregulated, especially in elevated CO2 conditions. For mycotoxin production, both on oat-based medium and in stored oats the production was higher at 25°C when compared to 30°C. In stored oats, at 0.98 aw, elevated CO2 led to higher T2/HT-2 toxin production at both 25 and 30°C with a significant increase (73-fold higher) at 30°C. In elevated CO2 conditions, Tri16 (Spearman test; 0.68; p-value=0.0019) and Tri5 gene expression (Spearman test; 0.56; p-value=0.0151) were correlated with T-2+HT-2 production. Nine T-2 and HT-2 metabolites were detected by LC-MS/MS including a new dehydro T-2 toxin and the conjugate, HT-2 toxin glucuronide (in plantae). The new dehydro T-2 toxin was the most abundant metabolites and showed correlation (R2=0.8176) with T-2 production. This is the first study to examine the impact of CC factors on growth and mycotoxin production by a strain of F. langsethiae. The influence of such scenarios on relative risk of oats contamination with these toxins in relation to the food security agenda is discussed.'
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    Data underpinning "Three-Dimensional Study of F. graminearum Colonisation of Stored Wheat: Post-Harvest Growth Patterns, Dry Matter Losses and Mycotoxin Contamination"
    (Cranfield University, 2020-08-07 08:19) Portell-Canal, Xavier; Garcia Cela, Esther; Verheecke, Carol; Medina Vaya, Angel; Otten, Wilfred; Magan, Naresh; Torrelles-RÃfales, Rosa
    Data used in the paper "Three-Dimensional Study of F. graminearum Colonisation of Stored Wheat: Post-Harvest Growth Patterns, Dry Matter Losses and Mycotoxin Contamination". Data is found in comma separated values files (e.g., "data1.csv") and the data content explained in text files (e.g., "data2_Readme.txt").
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    Data underpinning "Water and temperature relations of Fusarium langsethiae strains and modelling of growth and T-2 and HT-2 mycotoxin production on oat-based matrices"
    (Cranfield University, 2021-04-23 11:55) Verheecke, Carol; Garcia-Cela, Esther; Lopez-Prietro, Alejandro; Osk Jonsdottir, Inga; Medina Vaya, Angel; Magan, Naresh
    These data are linked to the paper Water and temperature relations of Fusarium langsethiae strains and modelling of growth and T-2 and HT-2 mycotoxin production on oat-based matrices.
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    Data underpinning the paper: Intra-species variability in Fusarium langsethiae strains in growth and T-2/HT-2 mycotoxin production in response to climate change abiotic factors.
    (Cranfield University, 2021-06-21 08:58) Verheecke, Carol; Lopez-Pietro, Alejandro; Garcia Cela, Esther; Medina Vaya, Angel; Magan, Naresh
    The objective of this study was to evaluate the potential intra-species variability of 3 Fusarium langsethiae strains in response to extreme climate change (CC) conditions on an oat-based matrix. The impact of elevated temperature (25 vs 30-34 °C) coupled with increasing drought stress (0.98 vs 0.95 aw ) and elevated CO2 (400 vs 1000 ppm) were examined on lag phases prior to growth, growth rate, and production of the mycotoxins T-2 and HT-2 and their ratio. In comparison to the control conditions (25 °C; 0.98; 400 ppm), exposure to increased temperature (30- 34 °C), showed similar reductions in the lag phase and fungal growth rates of all 3 strains. However, with elevated CO2 a reduction in both lag phases prior to growth and growth rate occurred regardless of the aw examined. For T-2 and HT-2 mycotoxin production, T-2 showed the most intra-species variability in response to the interacting abiotic stress factors, with the 3 strains having different environmental conditions for triggering increases in T-2 production: Strain 1 produced higher T-2 toxin at 25 °C, while Strain 2 and the type strain (Fl201059) produced most at 0.98 aw /30 °C. Only Strain 2 showed a reduction in toxin production when exposed to elevated CO2 . HT-2 production was higher at 25 °C for the type strain and higher at 30-34 °C for the other two strains, regardless of the aw or CO2 level examined. The HT-2/T-2 ratio showed no significant differences due to the imposed interacting CC abiotic conditions.
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    Dataset "Impact of Carbon Sources in Airport De-icing Compounds on the Growth of Sphaerotilus natans"
    (Cranfield University, 2024-09-12) Exton, Benjamin; Grabowski, Robert; Hassard, Francis; Medina Vaya, Angel
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    The impacts of airport de-icers on water quality and the growth of undesirable biofilms in rivers
    (Cranfield University, 2023-07) Exton, Benjamin Machael; Grabowski, Robert C.; Hassard, Francis; Medina Vaya, Angel; Natural Environmental Research (NERC)
    Undesirable river biofilms (URBs, formerly “sewage fungus”) are polymicrobial biofilms that grow in rivers as a response to organic pollution. Despite a continued widespread occurrence, limited research has been conducted in recent decades. Therefore, to reignite research into URBs, this thesis aims to investigate how the delivery of airport de-icer contaminated runoff to receiving waters impacts the growth and composition of URBs. The research conducted can be categorised into four themes: (i) a re-evaluation of “sewage fungus”; (ii) a field study to characterize the composition and drivers of URBs; (iii) microcosm growth experiments to determine how different airport de-icers contribute to URB growth; and (iv) pilot-scale mobilisation experiments to evaluate the mobilisation of airport de-icers in surface runoff. A bimonthly field study conducted over two winters revealed shifts in the bacterial composition of riverbed biofilms with suspected de-icer discharge. The community became dominated by the genera Rhodoferax (19.5 – 56.7% relative abundance) and Sphaerotilus (9.5 – 25.4%) prior to and during a visible URB incident. When aggregated at the family taxonomic level, Comamonadaceae (55.7 – 81.4%) emerged as the key indicator taxon of the significant shift in periphyton and has been proposed as a possible organic pollution biosentinel. The URB had a long-term influence on the periphyton, highlighting the importance of preventing their occurrence. Microcosm experiments of URB taxa growth using common freeze-point depressants as the sole carbon source confirmed de-icers can facilitate URB growth. Sphaerotilus natans growth was stimulated by all de-icers, except formate salts, in suspended culture (assessed by turbidimetric microcosms) and total growth was heavily dependent on carbon concentration. There were some significant differences in the growth kinetics between the active ingredients in de- icers (e.g., maximum growth rate). However, there were only negligible differences between pure active ingredients and their commercial products demonstrating that the additives used in commercial de-icers have negligible influence on microbial growth, despite their potential toxicity to aquatic fauna. Growth experiments with mixed cultures using S. natans and Zoogloea oleivorans were also tested to explore the interactions between URB taxa, including the novel application of timelapse microscopy in URB growth studies and provide a basis for further research. Mobilisation of commercial airport de-icers by rainfall was tested after exposure to various meteorological conditions (sun, wind, temperature) to explore the transport pathways of de-icers in runoff. Runoff was significantly affected by weather between de-icer application and a rainfall event. Sunlight and wind caused less de-icer mobilisation than decreases in temperature, attributed to drying effects. This research has considerable implications to inform surface water winter management plans by airport operators. This research highlights the continued prominence of URBs in rivers, even in countries with advanced wastewater treatment, and has added substantial contributions to knowledge about their composition and growth as a consequence of airport de-icing activities. Through a process-based understanding of de-icer transport and impact, airports can develop more effective and resilient solutions to minimise the ecological impacts in receiving water courses.