The Composition of Normal and Elongated Mycobacterium lepraemurium

SUMMARY: A process is described for preparing suspensions of Mycobacterium lepraemurium from livers of infected mice, free from traces of host tissue. The organisms doubled in length when incubated in ‘elongation medium’ for 12-14 days but did not multiply. Analyses of normal and elongated organisms were made for lipid, phosphorus, nucleic acids, hexosamines, neutral sugars and α-amino nitrogen. A doubling of dry weight occurred during elongation, and there was a net synthesis of each of the components measured. Lipid and neutral sugar more than doubled, phosphorus, nitrogen and total nucleic acid rather less than doubled and hexosamine and DNA increased by about one third.