Mycobacterium & Actinobacteria

http://en.wikipedia.org/wiki/Mycobacterium

Mycobacterium is a genus of Actinobacteria, given its own family, the Mycobacteriaceae. It includes many pathogens known to cause serious diseases in mammals, including tuberculosis and leprosy.

The Actinobacteria or Actinomycetes are a group of Gram-positive bacteria. Most are found in the soil, and they include some of the most common soil life, playing an important role in decomposition of organic materials, such as cellulose and chitin.