General Information: Produces thermostable enzymes. Members of this genus are distinguished from most actinomycetes by their ability to form clustered spores that attach directly to the substrate mycelia, and not to the aerial mycelia. Moreover, these bacteria do not produce aerial mycelia at all. M. fusca is the most thermophilic, with some growth detectable at up to 75 degrees C. The natural habitat of Thermobifida is self-heated organic materials, like rotting hay, compost, manure or urban waste piles, etc., which they share with other thermophilic and thermotolerant actinomycetes. Biological and physiological features of these bacteria are accordingly adapted to the conditions of such environments, namely the high temperatures and the presence of abundant plant materials and other bio-polymer substrates of natural origin. Actinomycetes are well suited for this environment because they generally grow as branching hyphae and are well adapted to penetration and degradation of insoluble substrates such as lignocellulose. Spores of Thermobifida are known to cause allergic respiratory diseases called mushroom worker disease and farmer's lung, which develop in agricultural workers who by the nature of their work happen to breathe in significant amounts of actinomycete spores from hay, compost, etc. Some isolates of this organism are able to mineralize plastic disposals and other anthropogenic xenobiotics. Thermobifidaare of particular interest because they produce multiple thermostable enzymes involved in the degradation of lignocellulose.