A genus of fungi whose species — for example Thermomyces lanuginosus — are used in the production of thermostable proteinases. Thermomyces species colonize composting and self-heating plant materials, secreting heat-stable enzymes such as lipases and xylanases that remain active at temperatures denaturing ordinary proteins. The lipase from T. lanuginosus is a workhorse of industrial biocatalysis, used in detergents and increasingly in food-related lipid modification. These fungi demonstrate why thermophiles are prized in biotechnology: their enzymes tolerate the hot, harsh conditions of real manufacturing processes.