Chaetomium species are strong producers of the enzyme cellulase. They are, therefore, adapted to growing on cellulosic (cellulose containing) materials. They thrive particularly on paper, straw and cotton. Chaetomium species have caused problems in libraries, military equipment and food. Apart from causing spoilage of various materials, they are also producers of mycotoxins. Because of their strong ability to biodegrade organic materials, several strains are used in mold growth testing.
The species commonly encountered in chronically water-damaged buildings is Chaetomium globosum. Chaetomium globosum is also a common “weed” of mushroom beds, where it inhibits the growth of cultivated mushrooms.