Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “MICROORGANISMS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 1,243 records · Page 69Linked to original sources
PubMed1983

Cyanuric acid--a s-triazine derivative as a nitrogen source for some soil microorganisms.

Cyanuric acid was not toxic for soil microorganisms examined and was even observed to stimulate the growth of Azotobacter in chernozem. Some isolated fungi were capable of cleaving the ring of cyanuric acid. With the use of 15N-labeled cyanuric acid it was found that the nitrogen taken from this compound by Aspergillus minutus and Pseudogymnoascus sp. was incorporated into their proteins. About 70-90% of 15N derived from cyanuric acid was detected in the biomass of the examined fungi. The ability of soil microorganisms to cleave the triazine ring is of importance in the detoxication of soils treated with triazine herbicides.

Bacteria↗
PubMed1982

[Opportunistic microorganisms: the causative agents of food toxicoinfections and acute intestinal diseases].

The analysis of sporadic morbidity due to acute intestinal infections and toxicoinfections caused by potentially pathogenic microorganisms is presented. The hypothesis stating that different pathogenic agents have different levels of pathogenic potential at a given stage of their evolution is proposed. Microorganisms with a low level of pathogenicity potential are characterized by the prevalence of the syndrome of toxicoinfection and by the rarity or absence of the syndrome of an acute intestinal disease. The prevalence of the latter is characteristic of potentially pathogenic microbes with a high level of pathogenicity potential making them similar to complete parasites.

Acute Disease↗
PubMed1983

Human polypeptidic hormone-like substances in microorganisms.

The presence of factors cross-reacting with polypeptidic human hormones (chorionic and pituitary gonadotropins, prolactin, ACTH and gastrin) has been studied with immune staining methods and agglutination tests in schizomycetes and protozoa of different origin. The bacteria strains freshly isolated from tumor patients do not react with the sera, whereas P. maltophilia ATCC 13637, some E. coli strains namely ATCC 12795, K12, 113/3, 1047, a free-living alga (O. malhamensis ATCC 11532) and a protozoon L. enrietti ATCC 30035 cross-react with the sera against hCG and its beta subunit. The last mentioned three bacterial strains (but neither the former one nor the eucaryotic microorganisms) react with rabbit sera raised against human pituitary gonadotropins, and a minority of this population react even with antibodies against human prolactin. B. mycoides ATCC 4004 reacts only with the latter antiserum. None of the examined microorganisms combines with antisera against other polypeptidic human hormones such as ACTH or gastrin. The bacterial production of hCG-like factor(s) by P. maltophilia is fairly high in Brain Heart Infusion Agar, disappears in cultures carried out in glucose-inorganic salt medium either plain or supplemented with growth factors or hCG beta-subunits, and is lost in tetracycline or chloramphenicol resistant mutans. The role played by joint sharing of antigens in conditioning the interaction between different organisms as well as the immune interfering properties of hCG are discussed.

Adrenocorticotropic Hormone↗
PubMed1984

[Microorganisms as potential producers of essential fatty acids].

The data on the importance of essential fatty acids in a balanced diet have been considered. The ways of essential fatty acid synthesis in microorganisms and their metabolism in animal tissues are being discussed. The criteria for microorganisms selection--producers of food lipids have been proposed.

Animal Nutritional Physiological Phenomena↗
PubMedDate not supplied

Host-grown Mycobacterium leprae: a credible microorganism.

In this paper recent advances in knowledge of the following aspects of Mycobacterium leprae will be reviewed: animal sources, ultrastructure, lipid composition, wall structure, molecular biology, metabolic capabilities and measurement of viability. It will be proposed that isolated from infected tissues are consistent, that is they share chemical and biochemical features although originating from many parts of the world, are unique, that is they have properties possessed by no other microorganism, and are biologically credible, meaning that their behaviour and properties are consistent with and sufficient for their postulated role as an intracellular pathogen. It is now clear that host-grown M. leprae is phenotypically quite distinct from organisms so far cultivated in vitro from infected tissues. The technique of DNA hybridization provides a method, unaffected by phenotypic changes brought about by transfer from a host to a medium, to compare host-grown M. leprae with cultivable microorganisms supposed to be genotypically identical.

Animals↗
PubMed1984

[Spoilage microorganisms encountered in ultra-high temperature processed milk].

40 strains of aerobic or facultative anaerobic microorganisms were isolated from a total of 37 spoiled ultra high temperature processed milk. 13 of them were identified as the genus Bacillus. They were 6 B. cereus, 5 B. licheniformis, 1 B. brevis and 1 B. pumilus. The other 27 strains were nonsporeforming microorganisms, which included 5 yeasts, 2 Pseudomonas sp., 3 Streptococcus sp., 12 Lactobacillus sp., 1 Shigella sp., 1 Aeromonas sp. and 3 Micrococcus sp. Results indicate that the spoilage of milk sample was caused mainly by the contamination during the filling operation. The Bacillus strains isolated were mesophilic or thermophilic, and some of them, were also psychrotrophic.

Animals↗
PubMed1978

[Microorganisms in the open air during the period of a winter-half-year (author's transl)].

During the winter-half-year 1976/77 the concentrations of airborne microorganisms in the open air were measured in Bonn and at a place in the Sauerland. Simultaneously the data of wind direction, wind speed, atmospheric rel. humidity, temperature, intensity of solar radiation were registered. It can be shown, that the denominated parameters are influencing the content of microorganisms of the air in different proportions.

Air Microbiology↗
PubMedDate not supplied

[Microorganisms destroying a number of nonionogenic surface-active substances].

Microorganisms destroying nonionogenic surfactants (NS) were selected. The isolated cultures were assigned to the genera Pseudomonas and Bacillus. Biodestruction of 19 NS was studied in Erlenmeyer flasks with shaking and in the course of continuous cultivation. The rate of destruction was shown to depend on the chemical structure of a substance: block-copolymers of ethylene and propylene oxides were more resistant to the action of microorganisms. The results indicate that sewage waters containing NS (at an initial concentration of 50 to 500 mg/l) can be purified on local installations using microbial cultures or their complexes.

Bacillus↗
PubMed1983

[Microorganisms as potential source of fats].

The production of fat and fatty acids from microorganisms have come up as a problem recently. Since, the fat originated from plants and animals in living world is not enough for the increasing world population. The most important problem was to select the true microorganisms for microbial fat production. Although the fact that bacteria grow fast but due to having small cellular mass production they were not chosen for this purpose, instead, various subspecies of yeast such as Candida, Rhodotorula were studied. These subspecies were generally grown up fast, having a highest cellular mass and giving a mixture of homogeneous fermentation liquor and collected easily by centrifugation.

Candida↗
PubMed1984

[Distribution of antibiotic-resistant microorganisms among newborn infants in an intensive care unit].

Bacteriological assay of the nasal, fauces and feces microflora of 40 newborns of the Department of Intensive Therapy revealed their primary colonization with various opportunistic microorganisms from the environment. Sensitivity of the isolates to 15 antibiotics was tested. It was shown that multiple resistance strains predominated. The staphylococcal strains were mainly resistant to benzylpenicillin, ampicillin, erythromycin and polymyxin. The enterococci were most frequently resistant to methicillin, lincomycin, kanamycin, monomycin and neomycin. Tetracycline and chloramphenicol resistant strains of E. coli were detected. Marked resistance to carbenicillin, ampicillin, cephuroxim and cephaloridin and high sensitivity to cephotaxim and gentamicin were determined in the Klebsiella strains with the method of serial dilutions on solid media. The presence of opportunistic microorganisms with multiple resistance to antibiotics, ate appearance of the own microflora and decreased immunological defence may be the cause of infection in newborns of departments of intensive therapy. Circulation of antibiotic-resistant strains in departments for newborns is fraught with a threat of hospital infections.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Phosphorimetric method to determine Zn-porphyrins in microorganisms and biological liquids].

A phosphorimetric technique of direct quantitative determination of Zn-porphyrins in microorganisms and biological liquids is described. The technique is based on the registration of visible light-induced afterglow and phosphorescence of Zn-porphyrins at room temperature under anaerobic conditions. The sensitivity of the technique is not less than 10(-8) M. Certain types of Zn-porphyrins can be identified with respect to the spectra of excitation and radiation of afterglow. The technique has been applied to study the afterglow of microorganisms (E. coli, St. aureus, B. subtilis, B. pioceaneum, M. tuberculosis) and of milk, serum, and urine.

Animals↗
PubMedDate not supplied

[Theoretical evaluation of necessity of carbon dioxide assimilation by microorganisms during growth on various substrates].

The biological role of exogenous carbon dioxide during substrate assimilation with a various degree of reductivity is evaluated. The investigation of metabolic pathways of carbon dioxide incorporation into the metabolic processes of methaneoxidizing bacteria shows that the HCO3- ion assimilation is catalyzed by phosphoenolpyruvate carboxylase and in certain strains also by the key enzyme of autotrophic pathway of the carbon dioxide assimilation, ribulose-1,5-diphosphate carboxylase. The theoretical calculations and experimental studies indicate that exogenous carbon dioxide is a necessary participant of the metabolic processes of methane or methanol assimilation. It is also an acceptor of the excess electrons of these compounds. It is the degree of reductivity of the substrate metabolized that determines the activity of the exogenous carbon dioxide fixation by microorganisms. The carbon dioxide fixation by heterotrophic microorganisms must be considered, therefore, as a process which is mostly due to the elementary composition of the source of carbon under conversion.

Bacteria↗
PubMedDate not supplied

[Proteolytic activity of conditionally pathogenic microorganisms causing food poisoning].

A study was made of proteolytic activity of the microorganisms Proteus and Bac. cereus, as well as of infected extract from raw meat. Subject to study were also the effects of the temperature, storage and microbial association on the production of exoproteases. The results indicate an increase in the proteolytic activity in the course of storage at room and decreased temperatures and a lowering of the soluble protein amount in the samples, which attests to an active process of spoiling. Association of the bacteria in question appears to be a factor with a certain effect of protease repression. It is necessary to exercise control over the amount of the microorganisms in foods with a high content of protein, and to revise the times of meat storage in refrigerators.

Animals↗
PubMed1981

[Effect of anaerobiosis in 6 blood-culture media on the recovery rate of aerobic microorganisms (author's transl)].

Commercially manufactured blood-culture bottles with 6 different culture media have been considered in this study. The bottles were respectively supplemented with 10% fresh human blood and inoculated with obligate aerobic and facultative anaerobic microorganisms known to cause bacteremia and fungemia. The inoculum size ranged from less than 10 to 10(2) CFU per blood-culture bottle. The study was carried out by alternately incubating one set of bottles anaerobically for two days before being vented, while the other set was vented immediately after inoculation. The effect of anaerobic and aerobic atmospheres on growth intensity, recovery rate and survival durability of the 11 microbial strains has been studied. The maintenance of anaerobic atmosphere for 2 days before venting the blood-culture bottles caused: a) 2 to 4 days delay in detecting nonfastidious bacteria and fungi; b) rapid death of acid-sensitive bacteria in poorly buffered culture media; c) inability of fastidious bacteria to grow in any of the 6 culture media. On the other hand venting the blood-culture bottles immediately after inoculation enabled: a) rapid detection of bacteria by an early subculture after 8 hours of incubation; b) diagnostic advantage of at least 2 days with rapidly growing bacteria which make more than 50% of the whole microbial spectrum; c) good growth of fastidious bacteria. Collectively, brain heart dipeptone broth proved to be the most effective culture medium for detection of obligate aerobic microorganisms responsible for bacteremia.

Acinetobacter↗
PubMed1982

[Proteolytic microorganisms in liver products].

Liver products were studied for the content of proteolytic microorganisms during production and storage. Their number was at the lowest level in products of thermal processing (10(5) per g on the average). Storage at a refrigerator and room temperature increased this level to the average values of 10(6) to 8.10(6) per g. Isolated colonies of proteolytic microorganisms were included in the following genera: Pseudomonas, Aeromonas, Escherichia, Alcaligenes, Bacillus and Staphylococcus. The content of ammonia was studied at the same time; ammonia was found to be in correlation with the numbers of proteolytes in the raw material and in the stored products.

Bacteria↗
PubMed1982

Nonspecific and cooperative binding of lectins to microorganisms.

Binding of lectins to microbial cell walls was investigated by fluorimetric titration and Scatchard plot. Data were correlated with agglutinability. Concanavalin A and lectins of wheat germ, soybean, pea, lentil, and peanut were tested against Escherichia coli. Micrococcus luteus, Lactobacillus plantarum, and Bacillus subtilis. In cases where binding occurred, it was either nonspecific or positively cooperative. Agglutination was observed only in those combinations of lectin and microorganism that showed positive cooperative binding, suggesting a definite relation between binding and agglutination. Lectins binding to the same carbohydrate did not necessarily bind to the same microorganism, confirming the complexity of the lectin-receptor bond.

Agglutination↗
PubMed1982

Hexachlorophene. Secondary microorganism resistance to hexachlorophene. Conjugative transfer inhibition by the R-plasmid-coded resistance by hexachlorophene.

Strain resistance of the genus Escherichia, Salmonella, and Pseudomonas to hexachlorophene is inducible. Secondary resistance of the Gram-negative microorganisms to hexachlorophene is an inherited property of these strains. There are not any explicit differences of primary sensitivity to hexachlorophene between sensitive strains and those resistant to antibiotics. The secondary resistance level of Gram-negative microorganisms to hexachlorophene is also not dependent on the natural resistance (or sensitivity) of strains to antibiotics. Hexachlorophene, in concentration of 10 micrograms/ml of conjugation mixture, causes 100% inhibition of the conjugation transfer of the resistance determinants to antibiotics from tested strains with conjugative R-plasmid. The indirect secondary resistance conjugation transfer to hexachlorophene was verified in two cases. The resistance to hexachlorophene was transferred, coupled with resistance to chloramphenicol, tetracycline, and streptomycin, from the Escherichia coli strains (No. 8) and Salmonella typhimurium (No. 4) to the recipient Escherichia coli strain K 12, SZK-Ec-329/74 (No. 2).

Anti-Bacterial Agents↗