Bacilysin, a hydrophilic substance formed by certain aerobic spore-forming bacteria that causes lysis in cultures of growing staphylococci, has been produced in aerated cultures of a strain of Bacillus subtilis (A14). A chemically defined medium was used, which contained glucose, Czapek-Dox salts and ferric iron. Production of bacilysin occurred, after a lag, while the culture was still undergoing rapid growth. 2. Bacilysin was adsorbed from the culture medium on Zeo-Karb 225 (SR5) (H(+) form) and eluted with aqueous pyridine. The crude material was purified by chromatography in pyridine-acetate buffers on columns of Dowex 50 (X2) and Dowex 50 (X8) respectively and by chromatography in aq. 70% (v/v) propan-2-ol on Sephadex G-25. 3. Purified bacilysin behaved as a single ninhydrin-positive substance when subjected to chromatography on paper in butan-1-ol-acetic acid-water and to electrophoresis on paper at pH4.5 or pH1.8. At pH4.5 the substance behaved as though it had no net change and at pH1.8 it migrated towards the cathode.
