PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “SARCINA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed1975

Microbial degradation of erythromycins A and B.

Growing cultures, as well as broken and lyophilized cells of pseudomonas 56 were found to degrade erythromycin A, and lyophilized cells inactivated erythromycins A and B. The enzyme system involved in this degradation was constitutive and the enzyme level in the cells could be increased about 8-fold when oleandomycin or erythromycin B was added to the growth medium. The ability of whole or broken cells to inactivate erythromycin A was completely lost when these preparations were boiled, and the erythromycin A-inactivating activity was localized in the cell membrane fraction. The lyophilized cells did not degrade oleandomycin, methymycin, tylosin, a mixture of leucomycins, josamycin, or maridomycin III.

Anti-Bacterial Agents↗
PubMed1978

CC-1065 (NSC-298223), a new antitumor antibiotic. Production, in vitro biological activity, microbiological assays and taxonomy of the producing microorganism.

A new antitumor antibiotic is produced in fermentation liquors of Streptomyces zelensis sp.n. The antibiotic is biologically active at extremely low concentrations. At 40 pg/ml, it inhibited 90% of the growth of L1210 cells in culture in tube dilution assays. The minimal inhibitory concentrations against Gram-positive bacteria is between 1 approximately 10 ng/ml, while these values for Gram-negative bacteria and fungi are mostly under 1 microgram/ml. A microbiological assay with Bacillus subtilis can detect concentrations of 1 approximately 2 ng/ml.

Animals↗
PubMed1978

The isolation and characterization of rubradirin B.

Rubradirin B, C40H33N3O15, was separated from other components of the rubradirin complex by chromatographic and crystallization procedures. The spectrum of antibacterial activity is similar to that of rubradirin, but the antibiotic is less active.

Animals↗
PubMed1975

[Distribution of Rifamycin SV in de Bovine Tissues Following Intramammary Administration of Rifamastene (author's transl)].

Depending on the physiological activity of the udder, from 4 to 95 per cent of the rifamycin SV administered by intrammary injection are absorbed from the udder and approximately 95 per cent of the absorbed rifamycin SV are excreted through the liver. The rifamycin SV eliminated in the faeces will lose its microbiological activity more or less rapidly, depending on the temperature and oxygen tension. Accumulation of rifamycin SV in the meat and organs will not occur on intramammary administration of this antibiotic. A balance between absorption and excretion is attained within sixty minutes after intramammary administration of Rifamastene in cattle. The maximum rifamycin SV concentrations determined in the serum, bile and urine were 0.12, 18.2 and 0.32 mug/ml respectively. Van Schothorst's S. lutea kidney test which is required by law in the Netherlands, was negative in every case.

Animals↗
PubMed1965

Ultra-high vacuum and microorganisms.

Experimental study of the space environment effect on living organisms is one of the most important tasks of exobiology. However location of the living organisms under study outside space vehicles and sputniks is combined with technical difficulties. Therefore it is much more suitable to reproduce conditions found in space in laboratory and to study its effect on living cells. It was proved that low temperatures, even those approaching absolute zero do not kill microorganisms. The fact of microorganisms surviving radiation of some million roentgen suggests that they would not be killed by ionizing radiation in space. UV rays should be considered as the most active sterilizing agent. The ability of microorganisms to resist high vacuum is studied much worse. Under the action of high vacuum at 10(-8)-10(-9) mm Hg during 72 hours all studied seven species of spore-forming bacilli remained viable. As for nonsporeforming bacteria under conditions mentioned, cells of some species perished (correction of parished) completely while other species retained viable cells. Conidia of fungi and parts of mycelium of fungi which do not form conidia, sustained high vacuum well.

Aspergillus fumigatus↗
PubMed1975

[Electron microscope study of bacteria in dental plaques following the application of fluorides (author's transl)].

Gels containing fluorides can have profound effects on dental plaques. These gels contain 2% fluorides in the form of sodium monofluorophosphate and sodium fluoride and are buffered to pH 6.5 when applied to teeth they: - encourage the disappearance of certain bacteria, - inhibit the division of cells and diminish their storage of glycogen, - cause a thickening of the bacterial cell wall, - lead to modifications of the bacterial cell membrane, - precipitate the degeneration of most forms of bacteria, - cause the rapid mineralisation of many bacteria. These widespread effects, and the wholesale degeneration of microbial forms, are a reflection of a major breakdown in bacterial metabolism, and provide a partial explanation for the role of fluorides in the prevention of dental caries, and are in accord with previous biochemical and microbial observations.

Adolescent↗
PubMedDate not supplied

[Generation time of pure cultures of heterotrophic microorganisms isolated from Lake Baĭkal].

Generation time was determined in pure cultures of heterotrophic microorganisms in the conditions similar to those of Baikal in June--July of 1972. Generation time was found to be 37+/-7, 16+/-2.5, 16+/-3.2, and 10+/-2.5 hours, respectively, when the cultures had been diluted with Baikal water in the following rations: 1 : 0,1 : 5,1 : 10, and 1 : 20. No differences in the growth rate were found among 11 cultures of heterotrophic microorganisms isolated from Baikal. Conditions limiting the microbial growth improve from the dilution of 1 : 0 to the dilution of 1 : 5. The mean time of generation is 27 hours for June--July. Generation time determined for pure cultures of heterotrophic microorganisms in the conditions similar to natural can be used to calculate production of the bacterial biomass for a definite period of the year.

Bacteria↗