Abstract
It is well-known that there are not a few strains of acid-fast bacilli developing visible growths on ordinary culture media, during attempts to cultivate leprosy bacilli, and most of them are merely regarded as contaminants. Mycobacterium KNBE strain, which had been isolated by T. NAKAYAMA from a subcutaneous nodular lesion in murine leprosy mouse, was, however, speculated as a variant of the causative agent.
The author studied the biological characters of this strain and found that its growth and elongation were accelerated by some kinds of peptone.
Based on the speculation that this strain might have some metabolic relations to murine leprosy bacilli, and with the ultimate aim to cultivate leprosy bacilli, the growth factor was isolated from a proteose peptone which had proved to show the above-mentioned activities.
This substance was estimated to possess a covalent bond with L-methionyl-L-leucine and Cu ion. And it was also demonstrated that a synthetic L-methonyl-L-leucine preparation had a similar effect on the strain.
From these results, it is concluded that the specific effects of the substance obtained from a proteose peptone depends on L-methionyl-L-leucine.
