Biomedical subjects

E M Singal

Publications and source records attributed to E M Singal.

At least 19 recordsLinked to original sources

PubMed1989

[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. By its taxonomic features the culture was classified as belonging to Micromonospora (subgroup II, Cinnamomea) and in particular to M. halophytica (Weinstein, Luedemann, Oden, Wagman, 1968). Up to now, it was known that lincomycin was produced only by Streptomyces cultures.

Agar↗

PubMed1986

[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. Biosynthesis, isolation, physico-chemical and biological properties of the antibiotic are described. The studies showed that galtamycin consisting of a chromophore and three unidentified sugars is a new compound differing from the known anthracyclines except trypanomycin by the absence of the UV absorption maximum at 230-240 nm. Galtamycin differs from trypanomycin by the molecular weight of the chromophore. Galtamycin showed low antitumor activity and was inactive against grampositive and gramnegative organisms and fungi.

Animals↗

PubMed1984

[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. At the same time the isolation frequency of gram-positive bacteria decreased from 88.5 to 9.6 per cent.

Bacteriological Techniques↗

PubMed1982

[Formation of antibiotic JI-20B by a culture of Streptomyces flavovirens].

An actinomycetous culture having an antibiotic action on gram-positive and gram-negative bacteria was isolated from a soil sample collected in the region of the Balaton Lake. As a result of the taxonomic study the culture was classified as Str. flavovirens. Waksman, Henrici (1948). Examination of antimicrobial properties of the antibiotic and chromatographic and mass-spectroscopic studies allowed one to classify it as an aminoglycoside belonging to the gentamicin group. The antibiotic was designated as J120-B. Until recently such antibiotics were known to be produced only by Micromonospora.

Culture Media↗

PubMed1981

[Directed screening of aminoglycoside antibiotic producers on selective media with gentamycin].

The method of directed screening of aminoglycoside antibiotics is based on the natural phenomenon that fresh isolates of Micromonospora are highly resistant to the antibiotics produced by them. The method consists of plating of the soil samples on selective media with gentamicin (10--25 micrograms/ml). The frequency of Micromonospora against the total number of the isolated actinomycetes increased from 3.3--11.4 to 30.6--78 per cent. The number of the cultures isolated from the control medium and active against gramnegative test-bacteria amounted to 13.4 per cent, while the number of Micromonospora isolated from the selective medium with gentamicin and active against gramnegative test-bacteria amounted to 69.4 per cent. 37 crude antibiotics were isolated with the method of ion exchange concentration usually used for aminoglycoside antibiotics. The new antibiotics were identified as 2-desoxy amine-containing aminoglycosides by cross resistance of aminoglycoside resistant strains of Staphylococci to them, the methods of paper and thin-layer chromatography and mass spectrometry. The majority of the aminoglycosides belonged to the gentamicin group. 2 compounds with molecular weights not described in the literature for aminoglycosides were isolated.

Aminoglycosides↗

PubMed1980

[Acylase activity of groups of actinomycetes and bacteria].

The acylase activity of 113 actinomycetous strains and 71 bacterial strains was studied. A number of strains producing acylases, hydrolyzing phenoxymethylpenicillin was detected among the actinomycetous cultures and a number of strains producing acylases active against ampicillin and benzylpenicillin was detected among the bacterial cultures. These acylases may be used in production of semisynthetic beta-lactam antibiotics and their semiproducts.

Actinomycetales↗

PubMed1979

[Methodological procedures for detecting antibiotic producers among cultures of the family Micromonosporaceae].

Data on intensification of the search for active cultures among Micromonospora are presented. It was shown that the frequency of detecting the antibiotic-producing cultures among Micromonospora under conditions of fermentation on the corn-glucose medium inoculated with agar blocks amounted to 35 per cent. The use of nutrient media of different composition for growing submerged inoculum of Micromonospora demonstrated that the rate of its growth reached maximum on the peastarch medium. The use of this medium for growing submerged seed material for fermentation in the corn-glucose medium increased the frequency of detecting active cultures from 35 to 43.1 per cent. The assay of Micromonospora antibiotic activity twice, i.e. in 96 and 240 hours of the fermentation process increased the frequency of detecting active cultures up to 57.1 per cent and revealing greater variety of antibiotics. Fermentation of Micromonospora cultures simultaneously on 6 different nutrient media inoculated with submerged seed mycelium and assay of the activity for 2 times, i. e. in 96 and 240 hours allowed a detection of up to 76.2 per cent of active strains out of the total number of the isolates.

Anti-Bacterial Agents↗

PubMed1978

[Directed isolation of Micromonospora generic cultures on a selective medium with gentamycin].

The results of using selective media with gentamicin for directed isolation of Micromonospora are presented. It was shown that the use of the selective media with gentamicin for isolation of actinomycetes from soils of usual humidity levels markedly increased the frequency of Micronomonospora detection. The use of the selective media with gentamicin for plating out silt substrates containing mainly Micromonospora had practically no effect on the increase in the number of the Micromonospora cultures grown. The number of antibiotic-producing Micromonospora isolated on the media with gentamicin was 3 times higher than that on the control media. The use of the selective media with gentamicin provided directed isolation of Micromonospora.

Culture Media↗

PubMed1978

[Directed isolation of Micromonospora generic cultures from moist soils and silts].

The data on the study of various soils and substrates for isolation of Micromonospora from them are presented. It was shown that Micromonospora predominated in moist soils and especially in such substrates as silts where their content with respect to the all actinomycetous isolates amounted to 88.9 per cent. In the silts the content of Micromonospora amounted to 66.6--83 per cent, in the sopromely its content was 66 per cent, while in the ordinary non-moist soil its content was from 6 to 11 per cent. Predominance of Micromonospora in silts and moist soils makes its directed search possible.

Asia, Eastern↗

PubMed1978

[Data on the conditions for the prolonged storage of Micromonospora generic cultures].

Data on studying various conditions for prolonged storage of Micromonospora are presented. It was shown that Micromonospora were satisfactorily stored under conditions of all maintenance methods used. The optimal methods were the following: storage of Micromonospora on agarized media under a layer of vaseline oil, storage of Micromonospora in the form of a mature submerged culture on liquid media optimal for its growth and development. Stimulating effect of low temperature on the spore germination was shown.

Culture Media↗

PubMed1974