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Why can fungi damage food, paper, textiles, leather, and timber?

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Two Amanita pantherina mushrooms with brown caps covered in white spots grow among moss and fallen leaves. — fungus A pair of panther cap mushrooms (*Amanita pantherina*). Closely related to the death cap mushroom (*Amanita phalloides*), the panther cap is highly poisonous.

Fungi can damage food, paper, textiles, leather, and timber because they are saprotrophic organisms that obtain their nutrition from nonliving organic matter.12

To feed, these fungi secrete digestive enzymes onto the surface of the material they are colonizing. These enzymes break down complex organic molecules—such as carbohydrates and proteins—into simpler compounds that the fungus can absorb through its hyphae to support its growth and reproduction.12

Because many of these materials are composed of organic substances like cellulose or protein derivatives, they serve as ideal nutritional substrates for fungi. This process of decomposition is particularly destructive in environments with high temperature and humidity, which facilitate fungal growth and the activity of their digestive enzymes. Consequently, when fungi invade these materials, their mycelia digest the structure of the item, leading to decay and eventual destruction.324