[Production of lincomycin by Micromonospora halophytica culture].

A Micromonospara culture designated as 991/78 with activity against gram-positive cocci and bacteria was isolated from samples of silt-covered substrates from the Amu-Darya. Directed screening on a selective medium supplemented with lincomycin in an amount of 50-100 micrograms/ml was used. Identification of the antibiotic produced by the culture showed it to be lincomycin.

[Grouping of Micromonospora based on their cultural-morphologic features, antibiotic-sensitivity and formation of antibiotics].

500 Micromonospora cultures were subdivided into nine groups on the basis of their cultural-morphological properties, the ability to produce antibiotics of certain chemical classes, and the sensitivity to 18 different antibiotics: aurantiaca (I), cinnamomea (II), cinnamomea-vinacea (III), cinnamomea-olivacea (IV), nigra (V), nigra-violacea (VI), lilacinescens (VII), coerulea (VIII) and brunnea (IX). Cultures belonging to groups I, II, III, V and VI are moderately sensitive to most of the antibiotics and often occur in natural substrates. Black Micromonospora cultures (groups V and VI) mostly produce aminoglycoside antibiotics while brown cultures (groups II and III) form macrolide antibiotics.

[The antibiotic galtamycin. Its fermentation, isolation, physicochemical and biological properties].

A culture of Streptomyces sp., producing an antibiotic named galtamycin was isolated from a soil sample collected in the Gorno-Altai Autonomous Region. The antibiotic belongs to anthracyclines.

[Directed isolation of gram-negative asporogenous bacteria from natural substrates].

A method for selective isolation of gramnegative nonsporulating bacteria from soil substrates was developed. The method consists of plating out the substrates on a glucose-yeast medium with addition of benzylpenicillin and nalidixic acid. The isolation frequency of gramnegative nonsporulating bacteria increased under such conditions from 9-16 (control) to 80-100 per cent.

[Taxonomic position of cultures of the family Micromonosporaceae].

The paper describes cultures that can be assigned to the genus Micropolyspora according to such properties as the presence of aerial mycelium, catenae of spores and galactose in the composition of sugars in the cell wall. However, the cultures contain xylose in the cell wall and therefore are related to the genus Micromonospora. These findings as well as the atypical proportion between DAPA and its isomers suggest that the cultures occupy an intermediate position between the genus Micromonospora and the genus Micropolyspora.