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Setting threshold limits for the significance of objectionable microorganisms in oral pharmaceutical products.

Due to the increasing number of immuno-compromised patients, increased attention is paid to the quantitation and identification of microorganisms in oral pharmaceutical products; therefore, a systematic approach is required by the manufacturers of non-sterile oral pharmaceuticals to evaluate the significance of microbial isolates other than primary pathogens and/or those in the product specification based on the number of organisms present, the type of dosage form, and the potential hazard to the user. Limits for objectionable microorganisms in oral products intended for use by immuno-compromised patient populations such as pediatric, HIV, cancer, etc., must be tighter than the limits for oral products intended for treating patients with diseases or conditions not affecting their immune systems because patients with deficient immune systems are more at risk of microbial infections. Smaller numbers of opportunistic pathogens become infectious when resistance mechanisms are impaired, either by severe underlying disease, or by use of immunosuppressive drugs. This article proposes a systematic approach for evaluating the significance of microbial isolates other than primary pathogens and/or those in the specification (e.g., Staphylococcus aureus and Pseudomonas aeruginosa) of non-sterile oral pharmaceutical products by setting appropriate threshold limits.

Administration, Oral↗

Uncoupling proteins in mitochondria of plants and some microorganisms.

Uncoupling proteins, members of the mitochondrial carrier family, are present in mitochondrial inner membrane and mediate free fatty acid-activated, purine-nucleotide-inhibited H+ re-uptake. Since 1995, it has been shown that the uncoupling protein is present in many higher plants and some microorganisms like non-photosynthetic amoeboid protozoon, Acanthamoeba castellanii and non-fermentative yeast Candida parapsilosis. In mitochondria of these organisms, uncoupling protein activity is revealed not only by stimulation of state 4 respiration by free fatty acids accompanied by decrease in membrane potential (these effects being partially released by ATP and GTP) but mainly by lowering ADP/O ratio during state 3 respiration. Plant and microorganism uncoupling proteins are able to divert very efficiently energy from oxidative phosphorylation, competing for deltamicroH+ with ATP synthase. Functional connection and physiological role of uncoupling protein and alternative oxidase, two main energy-dissipating systems in plant-type mitochondria, are discussed.

Acanthamoeba↗

Runoff of faecal microorganisms and nutrients from perennial grass ley after application of slurry and mineral fertiliser.

Perennial grass was fertilised with cattle slurry either surface-spread or injected into the soil. Slurry was spread once (early summer) in 1996 and 1997 and twice (both summer and autumn) in 1998 and 1999. The control was mineral fertilisation in summer. Faecal microbial numbers in surface runoff water were very high in late June 1998 soon after very heavy rains even though the last slurry application had been made almost one year earlier. There was no clear difference between slurry spreading methods. Autumn spreading of slurry lead to high microbial levels in runoff waters and water hygiene was protected better by slurry injection than by surface spreading. In spring, after snow melt, some faecal microorganisms were found in surface runoff water and the numbers of faecal microorganisms were less from plots with slurry surface spreading than those with slurry-injection. Losses of total phosphorus (TP) and total nitrogen (TN) in surface runoff were 2.7 and 7.7 kg/ha respectively from grass with surface-spread slurry in winter 1998-1999. The injection of slurry decreased TP and TN runoff by an average of 81% and 73% respectively. In 1999 there was little runoff because the summer was sunny and dry.

Agriculture↗

Genetic modification and selection of microorganisms for growth on Mars.

Genetic engineering has often been suggested as a mechanism for improving the survival prospects of terrestrial microoganisms when seeded on Mars. The survival characteristics that these pioneer microorganisms could be endowed with and a variety of mechanisms by which this can be achieved are discussed, together with an overview of some of the potential hurdles that must be overcome. Also, a number of biologically useful properties for these microorganisms are presented that could facilitate the initial human colonisation and ultimately the planetary engineering of Mars.

Bacteria, Anaerobic↗

[Effect of introduced microorganisms on copper and cobalt mobility in soil].

The paper deals with the change of copper and cobalt mobility in contaminated soil when activating microbiological processes by introduction of sources of carbon, nitrogen, phosphorus, metal-resistant microorganisms. When Bacillus cereus BKM 4368 growing in soil fertilized with glucose one can observe a 5-fold increase of cocentration of heavy-metal mobile forms as compared with sterile soil. The use of acetate as a carbon source and Alcaligenes euthrophus CH 34 culture as inoculum will provide a 3-fold decrease of concentration of copper and cobalt mobile forms in the process of microorganisms growth. Contribution of the soil microflora to the process of transformation of heavy metals under the investigated conditions was too low. The results obtained give a possibility to regulate the level of mobile forms of heavy metals in soil by means of choosing the adequate sources of carbon and microbial cultures.

Acetates↗

Synthesis of novel quinolines, pyranoquinolines, furoquinolines, thieno-quinoline and their effect on the ultrastructure of some pathogenic microorganisms.

New series of quinolines 2, 6, 7, 9, 14-17, 20, 21; pyrano[3,2-c]quinolines 3, 4, 5, 11; furo[3,2-c]quinolines 8, 18; oxazino[5,6-c]quinoline 19 and thieno[3,4-b]quinoline 22 were prepared and the impact of synthesized compounds on some pathogenic microorganisms isolated from clinical samples was studied. Compounds 4, 11 and 14 were found to be the most active against all tested microorganisms. The compound 14 which showed higher activity was selected to study its action on the ultrastructure of Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Death of numerous cells, destruction of the cell wall, cell contents poured into the medium and impairment of metabolism, were observed.

4-Quinolones↗

[Progress on the biosynthesis of medium-chain-length polyhydroxyalkanoates by microorganisms].

Polyhydroxylkanoates(PHAs) are a class of polyesters produced as reserve materials by a large number of microorganisms under metabolic stress. The most fascinating feature of PHAs is its degradability, and which is supposed to take place of the traditional plastics made from petroleum in the future. PHAs are divided into two classes: short-chain-length PHAs(scl-PHAs) and medium-chain-length PHAs. mcl-PHAs is more welcome owing to its more wide crystallinity and higher extension to break than scl-PHAs, especially when some kind of new functional groups were incorporated into the side chain of the polyester. Since Psedumonas oleovorans is the most typical microorganism to produce mcl-PHAs, here the author summarized how P. oleovorans synthesize the mcl-PHAs and the production of mcl-PHAs by fermentation and give some of the idea about the future research of this field.

Acyl Coenzyme A↗

[Efficacy of probiotic feed additives: guidelines for the evaluation of the efficiency of microorganisms in dogs, cats, and horses].

Probiotic microorganisms are frequently in use as feed additives for farm and pet animals. For admission for the common market products have to be tested according to the feed additive directive 70/524/EC. The dossier for admission has to comprise data of efficiency as laid down in the directive 87/153/EC. During the last years it became obvious after the evaluation of several dossiers, that no definitive criteria for the assessment of efficacy were available for dogs, cats and horses (84/153/EC). Aspects like the promotion of animal production are not relevant in this context. Therefore, the European commission launched the directive for the evaluation of efficacy of microorganisms for dogs, cats and horses, that supports the evaluation of microbial feed additives and which is described in this paper.

Animal Feed↗

[Stimulating and inhibiting effect of Spirulina platensis on microorganisms].

The blue-green microalga (cyanobacterium) S. platensis and the complex of its metabolites in the culture fluid being added into nutrient agar in doses of 0.01, 0.1 and 10 mg/ml, may produce a stimulating and inhibiting effect on microorganisms. In Spirulina biomass and in culture fluid substances which may be associated with the stimulation or inhibition of the growth of some microorganisms are supposedly contained. The manifestation of stimulating or inhibiting properties depended on the concentration of S. platensis and the complex of its metabolites, as well as on sterilization methods of nutrient media supplemented with these substances.

Bacteria↗

Effect of ultraviolet radiation on microorganisms as a principal extremal factor of space environment.

1. The problem of the transport of viable germs through interplanetary space has recently acquired special interest arising from the necessity of sterilization of space ships. 2. Of all cosmic extremal factors ultraviolet solar radiation is the most dangerous for microorganisms. The intensity of the most bactericidal region of ultraviolet radiation at a distance of one astronomical unit from the sun is 2 x 10(3) erg per cm2. 3. Sensitivity of microorganisms to ultraviolet rays varies in a large range. For the most resistant forms the lethal dose is approximately 440000 erg per cm2. 4. The penetrating capacity of ultraviolet radiation is very low, and therefore, even insignificant amounts of organic or mineral substances may protect the bacterial cell. 5. Dust particles of terrestrial origin carrying on themselves bacterial spores exert upon the latter a protective effect against ultraviolet radiation.

Bacteria↗

[Development of an experimental facility for waste treatment by microorganism].

Objective. To construct an experimental facility for microorganism waste processing, which will be used to recover plant nutrient liquids from plant inedible biomass essential for growth and development of plants. Method. After technical parameters and performance requirements were defined, plan demonstration, drawing design, fabrication, debug and preliminary plant inedible residue-biodegradation tests of microorganisms were conducted. Result. The temperature, stirring speed and gas-supplying flow of bioreactor of the facility were controlled automatically, as well as the pH and dissolved oxygen concentration were measured automatically and controlled manually, testifying that its performance reached the requirements of predetermined technical indexes. The 15-d test showed that the facility ran smoothly, its above-mentioned parameters could be measured and controlled precisely, and the biodegradation rate of lettuce's inedible biomass approximately attained 90%. Conclusion. The facility holding reasonable technical indexes, smooth and dependable performances, is capable of being utilized to biodegrade plant inedible biomass. It is expected that if the above-mentioned parameter combinations are optimized further, the results should be better.

Biodegradation, Environmental↗

[Adsorption of phenylurea derivative and chlorine-substituted aniline herbicides by microorganisms].

Adsorption of phenylurea derivatives and chlorosubstituted anilines by Pseudomonas and Aspergillus was studied. All these substances were adsorbed by the microorganisms in large quantities. The bacteria adsorbed more of these substances per biomass unit than the fungi. Adsorption of herbicides by the microorganisms is a physical process and is characterized by the same correlation as adsorption of herbicides by soil. Derivatives of phenylurea and chlorosubstituted anilines are easily washed from the cells with water. Conditions under which the substances were completely desorbed have been studied. Acetylation of 3,4-dichloroaniline by Pseudomonas aurantiaca results in desorption of 3,4-dichloroaniline from the cells of Pseudomonas boreopolis.

Adsorption↗

[Antagonistic interactions between stress factors during the growth of microorganisms under conditions simulating the parameters of their natural ecotopes].

Two stress factors, hypoxia (microaerobic conditions) and a high salt concentration, if applied simultaneously to aerobic microorganisms, display an antagonistic mode of interaction. As a result, the NaCl level that is usually optimal for moderate halophiles (5-6%) becomes optimal for the growth of weak halophiles (Rhodococcus erythropolis and Shewanella sp. CN32); the halotolerant yeast Yarrowia lypolytica acquires halophilic properties (with a growth optimum at a NaCl concentration of 10%), and the growth rate of the extremely halophilic Halobacterium salinarum increases at supraoptimal salt concentrations (25-34%). This phenomenon is apparently due to multiple changes in metabolic reactions. In particular, high salt concentrations suppress respiration and the formation of enzymes (superoxide dismutase and catalase) that protect the cell from toxic oxygen species. Therefore, establishment of microaerobic conditions compensates for the loss of these protective mechanisms and enables cell growth at higher salt concentrations than under aerobic conditions. Of some importance can also be the increase in the intracellular concentrations of osmoprotectants caused by the suppression of their intracellular oxidation. The implications of this phenomenon for the ecophysiology of microorganisms (including oiloxidizing species) and for the classification of weak and moderate halophiles are discussed.

Bacteria↗

Composting MSW and sewage sludge with effective complex microorganisms.

The effects of complex microorganisms in composting process of the municipal solid waste (MSW) and sludge were examined through inspecting biomass, temperature, oxygen consumption, organic mater, and C/N (the ratio of carbon and nitrogen). The experimental results shows: complex microorganisms are effective to compose organic matter and speedup composting change into humus.

Biomass↗

[Manganese-oxidizing microorganisms inhabiting the phylloplane].

Manganese oxidizing microorganisms belonging to the genus Metallogenium were found in the phylloplane of various trees and grass plants. This is the first evidence that epiphytes participate in the transformation of mineral elements, and that microorganisms belonging to the genus Metallogenium can be found not only in fresh water and soil.

Bacteria↗

[Catalase and superoxide dismutase in the cells of strictly anaerobic microorganisms].

Strictly anaerobic microorganisms relating to various physiological groups were screened for catalase and superoxide dismutase (SOD) activity. All of the investigated anaerobes possessed the SOD activity, necessary for protection against toxic products of oxygen reduction. High specific activities of SOD were found in Acetobacterium woodii and Acetobacterium wieringae. Most of the investigated clostridia and acetogens were catalase-negative. A significant activity of catalase was found in Thermohydrogenium kirishiense, in representatives of the genus Desulfotomaculum, and in several methanogens. Methanobrevibacter arboriphilus had an exceptionally high catalase activity after growth in medium supplemented with hemin. Hemin also produced a strong positive effect on the catalase activity in many other anaerobic microorganisms. In methanogens, the activities of the enzymes of antioxidant defense varied in wide ranges depending on the stage of growth and the energy source.

Bacteria, Anaerobic↗