Actinobacteria

The Actinobacteria are a group of Gram-positive bacteria. Most are found in the soil, and they include some of the most common soil life, playing important roles in decomposition and humus formation. Some form branching filaments, which somewhat resemble the mycelia of the unrelated fungi, among which they were originally classified as the Actinomycetes. A few forms are pathogens, such as Mycobacterium[?]. All are aerobic.

The Actinobacteria correspond to the high G+C group of Gram-positive bacteria, forms whose DNA contains unusually large amounts of the bases guanine and cytosine. Representative genera include:

• Actinomyces[?]
• Arthrobacter
• Corynebacterium[?]
• Frankia[?]
• Micrococcus[?]
• Mycobacterium[?]
• Nocardia[?]
• Streptomyces[?]