<prompt> Colonies of M. tuberculosis appear in about2 days2-8 weeks3-4 months7 days  <response>: Generation time : 14-15 hours. Colonies appear in about 2 weeks may take upto 8 weeks. Grows luxuriantly in culture Eugonic and addition of 0.5 glycerol improves its growth but it has no effect on M.Bovis, which is dysgonic Grows sparsely. Solid medium Most widely employed for routine culture is Lowenstein-Jensen LJ medium without starch. 