Which bacterial group is known as a primary source of natural antibiotics?

Actinomycetes are recognized as a primary source of natural antibiotics due to their unique metabolic capabilities and the soil-dwelling environment in which they thrive. These bacteria are a subgroup of the larger phylum Actinobacteria and are particularly known for their ability to produce a variety of secondary metabolites, many of which possess antibiotic properties. Notably, the genus Streptomyces, which falls under Actinomycetes, is responsible for the production of well-known antibiotics such as streptomycin, tetracycline, and erythromycin.

The diverse metabolic pathways and the ecological roles of Actinomycetes contribute to their ability to synthesize these compounds, which serve as a defense mechanism against competing microorganisms in their environment. This antibiotic production is also why they have become a focal point for antibiotic discovery in pharmaceutical research.

In contrast, while other groups such as Cyanobacteria, Firmicutes, and Proteobacteria may produce some bioactive compounds, none are as prominent as Actinomycetes in the context of natural antibiotic production. Cyanobacteria are primarily known for their photosynthetic capabilities, Firmicutes encompass many genera that include pathogens as well as beneficial bacteria, and Proteobacteria include a broad range of bacteria with diverse functions, but