title: [Selective medium with nalidixic acid for isolating antibiotic-producing Actinomyces].
abstract: The majority of actinomycetes belonging to various genera proved to be resistant to nalidixic acid concentrations having an inhibitory effect on bacteria with trailing growth i.e. B. subtilis and B. mycoides. The bacteria prevented isolation of actinomycetes as pure cultures. The use of a selective medium with nalidixic acid for isolation of soil actinomycetes resulted in 20 per cent increase in the number of the actinomycetes isolated as pure cultures. Preliminary treatment of the soil samples with calcium carbonate under moist conditions followed by the inoculation to the medium with nalidixic acid made it possible to increase isolation of actinomycetes at most 100-fold. With this complex method 495 actinomycete cultures were isolated, their antibiotic properties were studied and their taxonomic position at the genus level was determined. The complex method including the preliminary treatment of soil samples with calcium carbonate followed by inoculation to the selective medium with nalidixic acid is efficient and may be recommended for screening organisms producing new antibiotics.
authors.forename: I V
authors.initials: IV
authors.lastname: Alferova
authors.forename: L P
authors.initials: LP
authors.lastname: Terekhova
authors.forename: Kh
authors.initials: Kh
authors.lastname: Prauzer
mesh_terms: D000190:Actinomyces / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000096:biosynthesis; D002119:Calcium Carbonate / Q000494:pharmacology; D003470:Culture Media; D004352:Drug Resistance, Microbial; D004357:Drug Synergism; D066298:In Vitro Techniques; D009268:Nalidixic Acid / Q000494:pharmacology*; D012988:Soil Microbiology
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D009268:Nalidixic Acid; D002119:Calcium Carbonate
vernacular_title: Selektivnaia sreda s nalidiksovoĭ kislotoĭ dlia vedeleniia aktinomitsetov--produtsentov antibiotikov.