Probable Identity of an Antibiotic produced by a Spore-bearing Bacillus of the B. pumilus Group with Micrococcin

Abstract

THE production of an antibiotic by a species of Micrococcus, isolated from Oxford sewage, was reported by Su¹, who named the substance micrococcin. Later, Heatley and Doery² gave an account of the preparation and some of the properties of purified micrococcin. They showed it to be relatively insoluble in water, to darken and sinter at 222–28° without having a sharp melting-point, to show a maximum in its ultra-violet light absorption spectrum in ethanol at 345 mµ (E 1%, 1 cm., 180), to have [α]²¹ _D + 116° (c, 5.0) in 90 per cent ethanol, molecular weight greater than 2,000, and to give the following elementary analysis: C, 49–49.5; H, 4.6; N, 13.9; S, 15.9 per cent. They also stated that “it gives a positive ninhydrin reaction only after acid hydrolysis, but this seems to be due to ammonia, not amino-acids. Nothing is known of its chemical nature”. Still later, Fuller³ isolated from cultures of a spore-bearing bacillus of the B. pumilus group, originating in soil collected in East Africa, an antibiotic, sparingly soluble in water, which became discoloured at 232°, sintered at 238°, and appeared to melt at 252°; it gave the following elementary analysis: C, 48.9; H, 4.7; N, 13.7; S, 16.0 per cent. It did not appear to give a ninhydrin test even after hydrolysis with hydrochloric acid and was thought to be of non-peptide nature.