Ochratoxin A production by Aspergillus ochraceus Wilhelm grown under controlled atmospheres

Paster, N.; Lisker, N.; Chet, I.

doi:10.1128/aem.45.3.1136-1139.1983

Cited by 40 publications

(17 citation statements)

References 13 publications

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“…Studies by Paster et al (1983) reported that OTA production by A. ochraceus was completely inhibited by >30% CO 2 on agar-based media after 14 days. Diener and Davis (1977) working with Aspergillus flavus and groundnuts found that O 2 needed to be decreased to 5% before any effect on aflatoxin production was observed.…”

Section: Discussionmentioning

confidence: 99%

Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain

2005

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Aims:To examine the effect of interactions between water, temperature and gas composition on growth and ochratoxin A (OTA) production by isolates of Penicillium verrucosum in vitro and in situ on grain-based media and wheat grain. Methods and Results: Three isolates of P. verrucosum were examined in relation to radial growth rate and OTA production, and to interacting conditions of water activity (a w ), temperature and gas composition on a milled wheat medium. Subsequently, detailed temporal studies were carried out on gamma irradiated wheat grain over the range 0AE75-0AE995 a w , 10-25°C and air, 25 or 50% CO 2 . This showed that optimum growth of P. verrucosum was at 0AE98 a w in vitro at 25°C, but at 0AE95 a w and 25°C on wheat grain. The a w minimum for growth was about 0AE80 a w , although no OTA was produced under this condition even after 56 days. Significant inhibition of growth and OTA production occurred with 50% CO 2 , and 0.90-0AE995 a w at 25°C. Conclusions: The optimum and marginal conditions for growth and OTA production on wheat grain have been identified. At least 50% CO 2 is needed to inhibit growth and OTA production by >75% in moist grain (0AE90-0AE995 a w ). Significance and Impact of the Study: First detailed identification of optimal and marginal interacting conditions of water/temperature and gas composition on growth and OTA production by P. verrucosum on wheat grain. This is a critical component of the postharvest management strategy for minimizing contamination by this important mycotoxin and predicting risk, based on environmental conditions, during drying and storage.

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Section: Discussionmentioning

confidence: 99%

Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain

2005

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“…For example, the effects of elevated CO 2 on growth of Aspergillus ochraceus (=A. westerdijkiae), Penicillium verrucosum and ochratoxin A production have been determined (Paster et al, 1983;Cairns-Fuller et al, 2005). Recently, studies have suggested that up to 50% CO 2 had only a slight impact on ochratoxin A production by A. carbonarius over a range of a w conditions, with a w being a more important factor than CO 2 (Pateraki et al, 2007).…”

Section: Co 2 and Interaction With Other Key Environmental Factors Onmentioning

confidence: 99%

Possible climate‐change effects on mycotoxin contamination of food crops pre‐ and postharvest

Magan¹,

2011

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This paper examines the available information on the potential for climate-change impacts on mycotoxigenic fungi and mycotoxin contamination of food crops pre-and postharvest. It considers the effect of changes in temperature ⁄ water availability on mycotoxin contamination, especially incidences where aflatoxin B 1 and ochratoxin A production has been influenced. The potential of using preharvest models to predict risk from deoxynivalenol (DON) in wheat, fumonisin B 1 in maize and aflatoxins in maize and peanuts in different continents are considered in the context of potential for adaptation to include climate-change scenarios. Available information suggests that slightly elevated CO 2 concentrations and interactions with temperature and water availability may stimulate growth of some mycotoxigenic species, especially under water stress. The accumulated knowledge on interacting conditions of water ⁄ temperature effects on optimum and boundary conditions for growth and mycotoxin production has been used to predict the effects that +3 and +5°C increases under water stress would have on growth ⁄ mycotoxin production by mycotoxigenic species. Various spatial scales, from toxin gene expression to regional approaches using geostatistics, are examined for their use in understanding the impact that climate change may have on food contamination in developing and developed countries. The potential for using an integrated systems approach to link gene expression data, phenotypic toxin production under different interacting abiotic conditions is discussed using Fusarium species and DON as examples. Such approaches may be beneficial for more accurate predictions of risk from mycotoxins on a regional basis and also the potential for new emerging toxin threats.

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“…Fusarium species. For example, Paster et al (1983) reported that OTA production by A.ochraceus was completely inhibited by >30% CO 2 on agar-based media after 14 days suggesting that there are differences between mycotoxigenic species. This suggests that for efficient storage of moist cereals >50% CO 2 concentrations needs to be achieved rapidly to prevent OTA contamination in storage or during transport.…”

Section: More Comprehensive Studies Have Been Carried Out On Mycotoximentioning

confidence: 99%

Post-harvest control strategies: Minimizing mycotoxins in the food chain

Magan

Aldred

2007

International Journal of Food Microbiology

525

299

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Contamination of cereal commodities by moulds and mycotoxins results in dry matter, quality, and nutritional losses and represents a significant hazard to the food chain. Most grain is harvested, dried and then stored on farm or in silos for medium/long term storage. Cereal quality is influenced by a range of interacting abiotic and biotic factors. In the so-called stored grain ecosystem, factors include grain and contaminant mould respiration, insect pests, rodents and the key environmental factors of temperature, water availability and intergranular gas composition, and preservatives which are added to conserve moist grain for animal feed. Thus knowledge of the key critical control points during harvesting, drying and storage stages in the cereal production chain are essential in developing effective prevention strategies post-harvest. Studies show that very small amounts of dry matter loss due to mould activity can be tolerated. With <0.5% dry matter loss visible moulding, mycotoxin contamination and downgrading of lots can occur. The key mycotoxigenic moulds in partially dried grain are Penicillium verrucosum (ochratoxin) in damp cool climates of Northern Europe, and Aspergillus flavus (aflatoxins), A. ochraceus (ochratoxin) and some Fusarium species (fumonisins, trichothecenes) on temperate and tropical cereals. Studies on the ecology of these species has resulted in modelling of germination, growth and mycotoxin minima and prediction of fungal contamination levels which may lead to mycotoxin contamination above the tolerable legislative limits (e.g. for ochratoxin). The effect of modified atmospheres and fumigation with sulphur dioxide and ammonia have been attempted to try and control mould spoilage in storage. Elevated CO2 of >75% are required to ensure that growth of mycotoxigenic moulds does not occur in partially dried grain. Sometimes, preservatives based on aliphatic acids have been used to prevent spoilage and mycotoxin contamination of stored commodities, especially feed. These are predominantly fungistats and attempts have been made to use alternatives such as essential oils and anti-oxidants to prevent growth and mycotoxin accumulation in partially dried grain. Interactions between spoilage and mycotoxigenic fungi and insect pests inevitably occurs in stored grain ecosystems and this can further influence contamination with mycotoxins. Effective post-harvest management of stored commodities requires clear monitoring criteria and effective implementation in relation to abiotic and biotic factors, hygiene and monitoring to ensure that mycotoxin contamination is minimised and that stored grain can proceed through the food chain for processing.

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Ochratoxin A production by Aspergillus ochraceus Wilhelm grown under controlled atmospheres

Cited by 40 publications

References 13 publications

Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain

Water, temperature and gas composition interactions affect growth and ochratoxin A production by isolates of Penicillium verrucosum on wheat grain

Possible climate‐change effects on mycotoxin contamination of food crops pre‐ and postharvest

Post-harvest control strategies: Minimizing mycotoxins in the food chain

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