title: Polypeptide antibiotic 26a from Bacillus subtilis. II. Isolation and purification procedures.
abstract: Both the analytical and preparative methods by which the preparations of 26a bydrochloride salt with a high antibacterial activity and 20--30% recovery have been obtained from the fermentation fluids of Bacillus subtilis are presented. On an industrial scale the antibiotic can be yielded by absorption of bioactivity on Amberlite CG-50I column and precipitation with picric acid of crude substance from active elutes as adduct which was divided on equilibrated CM--cellulose and finally purified by gel filtration on Sephadex G-25 column. The purified preparation gave a single band by SDS-polyacrylamide gel electrophoresis and one ninhydrin-positive spot by thin-layer chromatography on silica gel G plates corresponding to single zones of bioactivity on bioautograms, and moved as a single peak of almost constant antibacterial activity on Sephadex G-75, G-100 and G-200 columns. The potency of the purest preparations, lot Sephadex G-25, was 6,500--7,000 arbitrary units/mg, and were characterized as follows: purification factor, 57; purity of 98--100% by densitometer scans of SDS-polyacrylamide gels; MIC for Sarcina lutea by twofold agar dilution assay, 0.306 microgram/ml.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D001412:Bacillus subtilis / Q000032:analysis*; D001681:Biological Assay; D002850:Chromatography, Gel; D002855:Chromatography, Thin Layer; D004591:Electrophoresis, Polyacrylamide Gel; D007422:Intestines / Q000382:microbiology; D007814:Larva / Q000382:microbiology; D007915:Lepidoptera / Q000382:microbiology*; D009036:Moths / Q000382:microbiology*; D010455:Peptides / Q000302:isolation & purification* / Q000494:pharmacology; D012505:Sarcina / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D010455:Peptides