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PubMed1987

[Significance of Haemophilus influenzae and other microorganisms for the pathogenesis and therapy of chronic respiratory infection].

The host's respiratory defence mechanisms are transformed to chronic inflammatory reactions by the persistence of microorganisms and hence inflict damage on the host's own tissues. This change primarily reduces the capability of the mucociliary defence mechanisms. Such impairment can result from modifications to the mucus's physical chemical properties after an infection, or from damage to the ciliary epithelium. Haemophilus influenzae, Pseudomonas aeruginosa and Streptococcus pneumoniae cause ciliary dyskinesia and eventually lead to the destruction of the ciliary epithelium. Encapsulated type b H. influenzae strains appear to slow down the cilia most markedly. There is a fundamental difference between acute and chronic infections. In the case of acute infections the patient's normal defence mechanisms are usually intact. In chronic infections the chronic inflammatory response to the microorganisms causes the disease to progress. In such cases treatment must be considerably more aggressive since the host's "cleansing" capability is diminished. Thus, antibiotics must be applied which can effectively penetrate the bronchial tree and which also remain stable and bioactive in the presence of beta-lactamase producing microorganisms such as H. influenzae. It is conceivable that, in the future, antibiotic therapy will have to be combined with antiphlogistic agents.

Anti-Bacterial Agents↗

PubMed1979

Microorganisms seen by scanning and transmission electron microscopy in Legionnaires' disease from human lung.

In addition to several anomalous structures, other general forms of definitely rod-shaped microorganisms have been found by scanning and transmission electron microscopy in the lung tissue taken at autopsy from a patient who succumbed to confirmed Legionnaires' disease with extensive necrotizing lobar pneumonia. The microorganisms were greatly varied in size and shape. They were micrographed in the act of fission. These forms have been found to some extent throughout the tissue. No nickel was demonstrated, either in the lung tissue or in the microorganisms.

Humans↗

PubMed1996

Spirochetal non-Borrelia-microorganism isolated from Ixodes ricinus.

Spirochetal microorganisms were isolated from female Ixodes ricinus in Slovakia. Morphological, immunochemical and molecular biological analysis showed that the microorganism shared several common antigens with Borrelia species while other genetic traits were distinct and not related to Borrelia burgdorferi sensu lato. Lyme disease patient's serum contained antibodies reacting with antigens of this microorganism. On the one hand the cross-reacting antigens represent a risk of false positive results in laboratory diagnostics, while on the other hand they have a certain potential for vaccine development against Lyme disease.

Animals↗

PubMed1979

Microorganisms in the rhizosphere of wheat colonized by the fungus Gaeumannomyces graminis var. tritici.

The population of microorganisms in wheat rhizosphere changed in the presence of the fungus Gaeumannomyces graminis var. tritici causing the take-all of wheat. In the majority of cases when the soil was artificially contaminated by the fungus, both the number of bacteria in the rhizosphere and the bacteria/fungi ratio temporarily increased. At the beginning bacteria growing in the presence of NH4+ predominated, later bacteria utilizing organic N-substances prevailed. Pseudomonas fluorescens and the related species colonized the rhizosphere and the soil to a greater extent in the presence of G. graminis. The wheat rhizosphere with G. graminis was found to contain a higher level of the slime-producing bacterium Agrobacterium spp.; this microorganism occurred on hyphal surfaces (in hyphosphere) of both G. graminis growing in soil and Mucor spp. Changes in microbial populations in the wheat rhizosphere during the first stage of colonization by G. graminis can be partly explained by a simultaneous rhizosphere colonization by microorganisms which accompany this fungus in soil. In the period of increase in the number of bacteria in rhizosphere a temporary stimulation of wheat growth was observed.

Actinomycetales↗

PubMed2002

Plant development in the absence of epiphytic microorganisms.

Microorganisms (bacteria, fungi) are common residents of the roots, stems and leaves of higher plants. In order to explore the dependency of plant development on the presence of epiphytic microorganisms, the achenes (seeds) of sunflower (Helianthus annuus L.) were sterilized and germinated under aseptic conditions. The sterility of the seedlings was determined with the agar impression method. In seedlings from non-sterile seeds (control) that were likewise raised in a germ-free environment, all plant organs investigated (stem, cotyledons and primary leaves) were contaminated with bacteria. Hypocotyl elongation was not affected by epiphytic microorganisms. However, the growth rates of the cotyledons and primary leaves were higher in sterile seedlings compared with the control. The implications of this differential inhibition of organ development by epiphytic bacteria that are transmitted via the outer surface of the seed coat are discussed. We conclude that epiphytes in the above-ground phytosphere are not necessary for the development of the sunflower seedling.

Bacteria↗

PubMed2000

Salt-tolerant phenol-degrading microorganisms isolated from Amazonian soil samples.

Two phenol-degrading microorganisms were isolated from Amazonian rain forest soil samples after enrichment in the presence of phenol and a high salt concentration. The yeast Candida tropicalis and the bacterium Alcaligenes faecoalis were identified using several techniques, including staining, morphological observation and biochemical tests, fatty acid profiles and 16S/18S rRNA sequencing. Both isolates, A. faecalis and C. tropicalis, were used in phenol degradation assays, with Rhodococcus erythropolis as a reference phenol-degrading bacterium, and compared to microbial populations from wastewater samples collected from phenol-contaminated environments. C. tropicalis tolerated higher concentrations of phenol and salt (16 mM and 15%, respectively) than A. faecalis (12 mM and 5.6%). The yeast also tolerated a wider pH range (3-9) during phenol degradation than A. faecalis (pH 7-9). Phenol degradation was repressed in C. tropicalis by acetate and glucose, but not by lactate. Glucose and acetate had little effect, while lactate stimulated phenol degradation in A. faecalis. To our knowledge, these soils had never been contaminated with man-made phenolic compounds and this is the first report of phenol-degrading microorganisms from Amazonian forest soil samples. The results support the idea that natural uncontaminated environments contain sufficient genetic diversity to make them valid choices for the isolation of microorganisms useful in bioremediation.

Alcaligenes↗

PubMed2003

Isolation of microorganisms for biological detoxification of lignocellulosic hydrolysates.

Acid pretreatment of lignocellulosic biomass releases furan and phenolic compounds, which are toxic to microorganisms used for subsequent fermentation. In this study, we isolated new microorganisms for depletion of inhibitors in lignocellulosic acid hydrolysates. A sequential enrichment strategy was used to isolate microorganisms from soil. Selection was carried out in a defined mineral medium containing a mixture of ferulic acid (5 mM), 5-hydroxymethylfurfural (5-HMF, 15 mM), and furfural (20 mM) as the carbon and energy sources, followed by an additional transfer into a corn stover hydrolysate (CSH) prepared using dilute acid. Subsequently, based on stable growth on these substrates, six isolates--including five bacteria related to Methylobacterium extorquens, Pseudomonas sp, Flavobacterium indologenes, Acinetobacter sp., Arthrobacter aurescens, and one fungus, Coniochaeta ligniaria--were chosen. All six isolates depleted toxic compounds from defined medium, but only C. ligniaria C8 (NRRL 30616) was effective at eliminating furfural and 5-HMF from CSH. C. ligniaria NRRL 30616 may be useful in developing a bioprocess for inhibitor abatement in the conversion of lignocellulosic biomass to fuels and chemicals.

Acids↗

PubMed2006

Convenient treatment of acetonitrile-containing wastes using the tandem combination of nitrile hydratase and amidase-producing microorganisms.

This study aimed to construct an acetonitrile-containing waste treatment process by using nitrile-degrading microorganisms. To degrade high concentrations of acetonitrile, the microorganisms were newly acquired from soil and water samples. Although no nitrilase-producing microorganisms were found to be capable of degrading high concentrations of acetonitrile, the resting cells of Rhodococcus pyridinivorans S85-2 containing nitrile hydratase could degrade acetonitrile at concentrations as high as 6 M. In addition, an amidase-producing bacterium, Brevundimonas diminuta AM10-C-1, of which the resting cells degraded 6 M acetamide, was isolated. The combination of R. pyridinivorans S85-2 and B. diminuta AM10-C-1 was tested for the conversion of acetonitrile into acetic acid. The resting cells of B. diminuta AM10-C-1 were added after the first conversion involving R. pyridinivorans S85-2. Through this tandem process, 6 M acetonitrile was converted to acetic acid at a conversion rate of >90% in 10 h. This concise procedure will be suitable for practical use in the treatment of acetonitrile-containing wastes on-site.

Acetonitriles↗

PubMed1996

Two-step degradation of pyrene by white-rot fungi and soil microorganisms.

The effect of soil microorganisms on mineralization of 14C-labelled pyrene by white-rot fungi in solid-state fermentation was investigated. Two strains of white-rot fungi, Dichomitus squalens and a Pleurotus sp., were tested. The fungi were incubated on milled wheat straw contaminated with [14C]pyrene for 15 weeks. CO2 and 14CO2 liberated from the cultures were determined weekly. To study the effect of soil microorganisms on respiration and [14C]pyrene mineralization in different periods of fungal development, the fungal substrate was covered with soil at different times of incubation (after 0, 1, 3, 5, 7, 9 or 11 weeks). The two fungi showed contrasting ecological behaviour in competition with the soil microflora. Pleurotus sp. was highly resistant to microbial attack and had the ability to penetrate the soil. D. squalens was less competitive and did not colonize the soil. The resistance of the fungus was dependent on the duration of fungal preincubation. Mineralization of [14C]pyrene by mixed cultures of D. squalens and soil microorganisms was higher than by the fungus or the soil microflora alone when soil was added after 3 weeks of incubation or later. With Pleurotus sp., the mineralization of [14C]pyrene was enhanced by the soil microflora irrespective of the time of soil application. With D. squalens, which in pure culture mineralized less [14C]pyrene than did Pleurotus sp., the increase of [14C]pyrene mineralization caused by soil application was higher than with Pleurotus sp.

Antibiosis↗

PubMed1997

Petroleum hydrocarbon bioremediation: sampling and analytical techniques, in situ treatments and commercial microorganisms currently used.

The sampling and analytical methods, along with available microorganisms, used for in situ hydrocarbon bioremediation are reviewed. Each treatment method is briefly described and its advantages and limitations pertaining to potential applications are evaluated. Bioremediation provides cost-effective, contaminant- and substrate-specific treatments equally successful in reducing the concentrations of single compounds or mixtures of biodegradable materials. In situ treatments rarely yield undesirable byproducts, but precautions and preliminary baseline tests are always recommended. Sampling methods should adhere to good laboratory and field practices and usually do not require highly trained personnel. Analytical methods vary in sensitivity, cost, duration of sample analysis and personnel training required. Voucher specimens of bacterial strains used in bioremediation exist in various repositories (e.g. ATCC, DSM, etc.) or are commercially available, and are usually covered by patent rights. Each one of these strains may yield spectacular results in vitro for specific target compounds. However, the overall success of such strains in treating a wide range of contaminants in situ remains limited. The reintroduction of indigenous microorganisms isolated from the contaminated site after culturing seems to be a highly effective bioremediation method, especially when microorganism growth is supplemented by oxygen and fertilizers.

Bacteria↗

PubMed2004

Influence of dipeptidyl peptidase inhibitors on growth, peptidase activity, and ammonia production by ruminal microorganisms.

The aim was to investigate known and potential new inhibitiors of dipeptidyl peptidases (DPP) for their effects on ruminal microorganisms. Gly-Phe diazomethylketone (GPD), Ala-Ala chloromethylketone (AAC), benserazide (DL-serine 2-(2,3,4- trihydroxybenzyl) hydrazide), and diprotin A (Ile-Pro-Ile) inhibited DPP activities of Prevotella albensis, P. ruminicola, P. bryantii, P. brevis, and mixed ruminal microorganisms, though incompletely and, except for diprotin A, without absolute specificity for any of the peptidases. Leucine aminopeptidase activity of Streptococcus bovis was also inhibited by GPD and benserazide. The inhibitors had no effect on the growth of the bacteria, except for GPD, which inhibited growth of P. albensis when only peptides were available for growth. Benserazide had some inhibitory effects on the growth of Megasphaera elsdenii and Prevotella spp., even in the absence of peptides. The predatory activity of ciliate protozoa on bacteria was unaffected by DPP inhibitors. Ammonia production from casein by mixed ruminal microorganisms was inhibited significantly (P < 0.05) by AAC (29% inhibition) and benserazide (33%). It was concluded that DPP inhibitors can influence the rate of NH3 production in the rumen and may form the basis for developing protein-sparing feed additives for ruminants.

Amino Acid Chloromethyl Ketones↗

PubMed2006

Impact of an herbicide combination of bromoxynil and prosulfuron on soil microorganisms.

Soil microcosm experiments were used to investigate the effects on growth and activity of soil microorganisms of an herbicide combination (60% bromoxynil + 3% prosulfuron) frequently used to provide a broad spectrum control of weed species. Culturable aerobic bacteria, fungi, and actinomycetes, the fundamental groups of heterotrophic microorganisms, and nitrifiers, considered a very sensitive group to these compounds, were evaluated. Since herbicides have been found to inhibit decomposition of cellulose in soil, the effects on cellulolytic bacteria and fungi were determined. Dehydrogenase activity as a measure of microbial activity was another parameter considered. The results emphasized a tendency of reversible stimulatory/inhibitory effects of the tested compounds on soil microorganisms, with fungi as an exception. A long-lasting negative action on the activity of the dehydrogenase (DHA), commonly used as an index of the overall microbial activity in soil, was found. The magnitude of these effects were dependent on the assayed concentrations of the herbicides mixture. We concluded that the presence of bromoxynil + prosulfuron could induce significant changes in the microbial populations of the soil, concerning the activity and balance of microbial community. Possible environmental risks must be considered. Dehydrogenase activity was shown to be an important indicator of side-effects attributed to these herbicides.

Actinobacteria↗

PubMed1998

Lateral and perpendicular interaction forces involved in mobile and immobile adhesion of microorganisms on model solid surfaces.

Gliding and near-surface swimming of microorganisms are described as a mobile form of microbial adhesion that need not necessarily be reversible. It is argued that the reversibility of microbial adhesion depends on the depth of the secondary interaction minimum, calculated from the forces between an organism and a substratum acting in a direction perpendicular to the substratum surface. The mobility of adhering microorganisms depends on lateral interactions between the organisms. On ideally homogeneous and smooth model surfaces, only mobile adhesion occurs because the multibody, lateral interactions are weak compared with the thermal or Brownian motion energy of the organisms. Minor chemical or structural heterogeneities, which exist on all real-life surfaces, yield a lateral interaction on adhering microorganisms. This causes their immobilization, which helps to explain the physicochemical nature of microbial gliding or near-surface swimming. Moreover, these lateral interaction energies are one order of magnitude smaller than the Lifshitz-Van der Waals, electrostatic, and acid-base forces acting perpendicular to substratum surfaces that are responsible for adhesion.

Bacterial Adhesion↗

PubMed2004

Distribution, diversity and activity of microorganisms in the hyper-alkaline spring waters of Maqarin in Jordan.

The hyper-alkaline, high-Ca(2+) springs of Maqarin, Jordan, were investigated as an analogue for various microbial processes at the extremely high pH generated by cement and concrete in some underground radioactive waste repositories. Leaching of metamorphic, cementitious phases in Maqarin has produced current, hyper-alkaline groundwater with a maximum pH of 12.9. Six consecutive expeditions were undertaken to the area during 1994-2000. The total number of microorganisms in the alkaline waters was 10(3)-10(5) cells/ml. Analysis of the 16S-ribosomal ribonucleic acid (rRNA) diversity revealed microorganisms mainly belonging to the Proteobacteria. Obvious similarities between the obtained sequences and sequences from other alkaline sites could not be found. Numerous combinations of culture media compositions were inoculated with spring, seepage and groundwaters and incubated under aerobic and anaerobic conditions with various carbon sources. Assimilation studies were performed using identical radio-labeled carbon sources. Glucose seemed to be the preferred carbon source for assimilation, followed by acetate, lactate, and leucine. The results demonstrate that microorganisms from the hyper-alkaline springs of Maqarin could grow and be metabolically active under aerobic and anaerobic hyper-alkaline conditions. However, the growth and activity found were not vigorous; instead, slow growth, low numbers, and a generally low metabolic activity were found. This suggests that microbial activity will be low during the hyper-alkaline phase of cementitious repositories.

Carbon↗

PubMed2002

Studying marine microorganisms from space.

Microorganisms are but a few micrometers in diameter and are not visible to the naked eye. Yet, the large numbers of microorganisms present in the oceans and the global impact of their activities make it possible to observe them from space. Here a few examples of how microorganisms can be studied from satellites are presented. The first case is the best known: the main pigment used in photosynthesis (chlorophyll a) can be determined from satellites. These kinds of studies have contributed a tremendous amount of understanding about the distribution and dynamics of primary production in the oceans. Two other examples will concern analysis of heterotrophic prokaryotic production and estimates of dimethyl sulfide (DMS) concentration and flux to the atmosphere. These three processes are of fundamental importance for the functioning of the biosphere. Marine microbes carry out about half of the total primary production in the planet. A substantial fraction of the respiration in the oceans is due to the activity of heterotrophic prokaryotes. Finally, the flux of DMS to the atmosphere is believed to constitute one of the mechanisms by which the biota can regulate climate. The global implications of microbial processes in the oceans can only be addressed with the help of satellites.

Chlorophyll↗

PubMed2006

Ammonia removal from livestock wastewater by ammonia-assimilating microorganisms immobilized in polyvinyl alcohol.

We isolated ammonia-assimilating microorganisms from the livestock manure treatment systems and evaluated their ammonia-assimilating ability. Many isolates utilized ammonia at high rates when they were purely cultivated in a nitrogen-limited medium to which sterilized lagoon extract had been added. Some isolates that were immobilized in polyvinyl alcohol (PVA) utilized ammonia present in the media containing viable lagoon microorganisms. Staining with 4',6'-diamidino-2-phenylindole (DAPI) indicated that the immobilized high ammonia-assimilating isolates grew dominantly within the PVA beads. High ammonia-assimilating isolates in the mixed culture containing viable lagoon microorganisms were identified as Pseudomonas spp. and member of Rhizobiaceae species by partial sequencing of the 16S ribosomal DNA.

Ammonia↗

PubMed2005

Monitoring of petroleum hydrocarbon degradative potential of indigenous microorganisms in ozonated soil.

This study was performed to investigate the petroleum hydrocarbon (PH) degradative potential of indigenous microorganisms in ozonated soil to better develop combined pre-ozonation/bioremediation technology. Diesel-contaminated soils were ozonated for 0-900 min. PH and microbial concentrations in the soils decreased with increased ozonation time. The greatest reduction of total PH (TPH, 47.6%) and aromatics (11.3%) was observed in 900-min ozonated soil. The number of total viable heterotrophic bacteria decreased by three orders of magnitude in the soil. Ozonated soils were incubated for 9 weeks for bioremediation. The number of microorganisms in the soils increased during the incubation period, as monitored by culture- and nonculture-based methods. The soils showed additional PH-removal during incubation, supporting the presence of PH-degraders in the soils. The highest removal (25.4%) of TPH was observed during the incubation of 180-min ozonated soil during the incubation while a negligible removal was shown in 900-min ozonated soil. This negligible removal could be explained by the existence of relatively few or undetected PH-degraders in 900-min ozonated soil. After a 9-week incubation of the ozonated soils, 180-min ozonated soil showed the lowest TPH concentration, suggesting that appropriate ozonation and indigenous microorganisms survived ozonation could enhance remediation of PH-contaminated soil. Microbial community composition in 9-week incubated soils revealed a slight difference between 900-min ozonated and unozonated soils, as analyzed by whole cell hybridization. Taken together, this study provided insight into indigenous microbial potential to degrade PH in ozonated soils.

Hydrocarbons↗

PubMed1979

Clinical uses of microorganisms and their products.

Although antibiotics and conventional vaccines are the two most familiar examples of man's exploitation of microorganisms as clinical allies, microorganisms and their products are assuming an increasingly prominent role in the diagnosis, treatment and prevention of human diseases. This report attempts to give a brief overview of the status of the use of microorganisms in clinical medicine and to identify potentially fertile areas for future progress in their clinical application, concentrating on areas other than the already extensively reviewed ones of antibiotics and classic immunization.

Antigens, Bacterial↗