Fungi differ widely in the range of temperature over which growth can occur and those conditions optimum for growth (Magan 1997). For example, Penicillium species such P. aurantiogriseum and P. verrucosum can grow over the range — 4 to + 35°C while Aspergillus fumigatus has a very wide tolerance of 10-55°C and Humicola lanuginosa in the range 30-60°C. The majority of fungi involved in deterioration in stored grain ecosystems thrive over the range 10-40°C with optima in the range 25-35°C. Lowering temperature reduces the metabolic activity of fungi and the grain, enabling longer mold-free storage periods. However, moist grain can be prone to slow deterioration by the genera Alternaria, Penicillium, and Fusarium, with species in each able to produce mycotoxins. Temperature of grain is a good indicator of quality during storage. Pockets of moisture can allow initiation of fungal activity that produces metabolic heat resulting in a succession of fungi becoming dominant and ending with spontaneous heating and dominance by thermotolerant/thermophilic fungi and actinomycetes (Lacey and Magan 1991).
fungal community can be very different colonization of grain pre- and postharvest are described separately.
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