Actinomycetes in Hypogean Environments

Most hypogean environments, particularly caves, are characterized by a stable temperature, usually in the range of 10-15degreeC, and high relative humidity. These ecosystems, when an allochthonous input of organic matter is present, seem to favor the growth of heterotrophic bacteria, from which actinomycetes predominate. Streptomyces species are particularly abundant and, in some cases, can be found as monospecific colonies. The mechanisms involved in colonization and growth are unknown, but microclimate and carbon sources can play an important role.