Purification and some properties of an antibacterial factor derived from bacillus subtilis fhc 4o₂

Bacillus subtilis FHC 402-derived antibacterial factor (abbreviated to BAF), which showed antibacterial activity by its combined use with hexametaphosphate, was purified from a culture broth by means of column chromatography on octyl-Sepharose CL-4B, DEAE-Cellulofine AL and Bio-Gel P-6. BAF was purified 63-fold with an activity yield of 17%. The purified preparation gave a single band on the electrophoregram. BAF may be a glycopeptide containing 22 molecules of 8 different amino acids, 3 hexoses, 1 hexosamine, 1 deoxyribose, and unknown substances. The N-terminal amino acid of the BAF preparation was determined to be tyrosine and the C-terminal amino acid to be proline. Gel filtration estimated the molecular weight of the BAF preparation at 3, 200. The purified BAF preparation was stable in a pH range from 5.0 to 11.0, was also stable on heating, but was unstable at pH 3.0.