title: [Azotobacter chroococcum, a producer of a new antifungal antibiotic].
abstract: Strain 92 of Azotobacter chroococcum was obtained as result of natural selection. It produces an antibiotic active against phytopathogenic fungi. The antibiotic was isolated from the bacterial mass of the culture with ethanol extraction followed by column and thin-layer chromatography on silica gel. The pure antibiotic is a viscous oily substance of a yellowish colour, readily soluble in the majority of the organic solvents, not soluble in water, readily oxidized by air oxygen. The UV absorption spectrum of the antibiotic ethanol solution had bonds characteristic of the conjugated tetraene system. The presence of ketone and enol groups in the antibiotic molecule was shown with the colour reactions. It was confirmed by the data of the antibiotic IR spectrum investigation. According to the data of high resolution mass spectroscopy the empirical formula of the antibiotic is C20H30O4, the molecular weight is 334. It is suggested that the antibiotic is an ester of aliphatic tetraenic acid differing from the known antibiotics produced by Azotobacter.
mesh_terms: D000935:Antifungal Agents / Q000032:analysis / Q000096:biosynthesis*; D001395:Azotobacter / Q000378:metabolism*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002855:Chromatography, Thin Layer; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000935:Antifungal Agents
vernacular_title: Azotobacter chroococcum--produtsent novogo protviogribkovogo antibiotika.