Mycobacterium tuberculosis (M. tb) may be a species of pathogenic bacteria within the Mycobacteriaceae and therefore the causative agent of tuberculosis. First discovered in 1882 by Koch , M. tuberculosis has an unusual, waxy coating on its cell surface primarily thanks to the presence of mycolic acid. tubercle bacillus may be a human pathogen that has had a staggering global impact. Its origins are ancient. Spinal deformities typical of these resulting from M. tuberculosis disease are found in human remains as far apart as Peru and Egypt and dating from a minimum of 5000 BCE. tubercle bacillus grows slowly: it reproduces itself every 24 to 48 hours. this is often extremely slow for bacteria. There are other bacteria that reproduce every 20 minutes.Usually bacteria are identified by adding coloring agents to the laboratory surface on which they grow.