Actinobacteria is having genus called Mycobacterium, with its own family, the Mycobacteriaceae. It includes pathogens known to cause deadly diseases in mammals, including tuberculosis and leprosy . The mycobacteria is not a fungi but a bacteria which grows in a mold-like fashion on the surface of cultures . Its Pathogenicity shows adverse signs which can colonize their hosts without the hosts and their infections are notoriously difficult to treat. As Mycobacterium tuberculosis is the causative agent of tuberculosis and it kills nearly 2 million people in the world each year. Mycobacterium has phenolic alcohols known as Mycosides composed of Mycobacterium glycolipids that are termed glycosides of phenolphthiocerol dimycocerosate. Comparative Genomics studies shows that conserved indels and signature proteins that are uniquely found in all sequenced species from the genus Mycobacterium. Phenotypic tests can be used to identify and distinguish different Mycobacteria species and strains. Mycobacteriophage can infect Mycobacterium, so in future bacterial viruses may be used to treat tuberculosis and related diseases by phage therapy.