Rayan Zahr*, Sarah Zahr, Rana El Hajj and Mahmoud Khalil
Actinomycetes are gram-positive bacteria detected in various terrestrial and aquatic environments. Many of them develop mycelia and exhibit complicated structural differentiation. Actinomycetes have been identified using a variety of methods, namely morphological, chemotaxonomic, and molecular techniques. Because of the extensively emerging antimicrobial-resistant organisms affecting human health and agriculture, as well as the increasing incidence of cancer, new drugs are urgently needed to combat different diseases and microbial infections. The majority of antimicrobials now in use are of natural origin. Among them, actinomycetes constitute a significant source of bioactive compounds used in drug development.
Actinomycetes provide almost 45% of the secondary metabolites, followed by fungi recording 38%, and other bacteria that produce only 17%. Secondary metabolites derived from actinomycetes exhibit a wide spectrum of biological activities targeting both the pathogens and the host. This review emphasizes the classification of diverse actinomycetes and lists their importance, with an emphasis on the secondary metabolites and their different biological activities.