microbial dynamics
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Although phosphine is ubiquitously present in anaerobic environments, little is known regarding the microbial community dynamics and metabolic pathways associated with phosphine formation in an anaerobic digestion system. This study investigated the production of phosphine in anaerobic digestion, with results indicating that phosphine production mainly occurred during logarithmic microbial growth. Dehydrogenase and hydrogen promoted the production of phosphine, with a maximum phosphine concentration of 300 mg/m3. The abundance of Ruminococcaceae and Escherichia was observed to promote phosphine generation. The analysis of metabolic pathways based on the Kyoto Encyclopedia of Genes and Genomes (KEGG) and the MetaCyc pathway database revealed the highest relative abundance of replication and repair in genetic information processing; further, the cofactor, prosthetic group, electron carrier, and vitamin biosynthesis were observed to be closely related to phosphine formation. A phylogenetic tree was reconstructed based on the neighbor-joining method. The results indicated the clear evolutionary position of the isolated Pseudescherichia sp. SFM4 strain, adjacent to Escherichia, with a stable phosphate-reducing ability for a maximum phosphine concentration of 26 mg/m3. The response surface experiment indicated that the initial optimal conditions for phosphine production by SFM4 could be achieved with nitrogen, carbon, and phosphorus loads of 6.17, 300, and 10 mg/L, respectively, at pH 7.47. These results provide comprehensive insights into the dynamic changes in the microbial structure, isolated single bacterial strain, and metabolic pathways associated with phosphine formation. They also provide information on the molecular biology associated with phosphorus recycling.
- MeSH
- anaerobióza MeSH
- bioreaktory mikrobiologie MeSH
- Clostridiales genetika metabolismus MeSH
- dusík metabolismus MeSH
- Escherichia genetika metabolismus MeSH
- fosfáty metabolismus MeSH
- fosfiny analýza metabolismus MeSH
- fosfor metabolismus MeSH
- fylogeneze MeSH
- metabolické sítě a dráhy * genetika MeSH
- mikrobiota * MeSH
- odpadní vody mikrobiologie MeSH
- vodík metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
The variation in house dust mite microbial communities is important because various microorganisms modulate the production of allergens by their mite hosts and/or contaminate immunotherapeutic extracts. Temporal changes in mite microbiomes and the mite culture environment occurring at different stages of mite culture development are particularly understudied in this system. Here, we analyzed the dynamics of microbial communities during the culture growth of Dermatophagoides farinae. Changes in microbiomes were related to three key variables: the mite population density, microbial microcosm respiration and concentration of guanine (the mite nitrogenous waste metabolite). Mite populations exhibited the following phases: exponential growth, plateau and exponential decline. The intracellular bacterium Cardinium and the yeast Saccharomyces cerevisiae prevailed in the internal mite microbiomes, and the bacterium Lactobacillus fermentum was prevalent in the mite diet. The reduction in the mite population size during the late phases of culture development was related to the changes in their microbial profiles: the intracellular bacterium Cardinium was replaced by Staphylococcus, Oceanobacillus and Virgibacillus, and S. cerevisiae was replaced by the antagonistic fungi Aspergillus penicillioides and Candida. Increases in the guanine content were positively correlated with increases in the Staphylococcus and A. penicillioides profiles in the culture environment. Our results show that the mite microbiome exhibits strong, dynamic alterations in its profiles across different mite culture growth stages.
- MeSH
- alergeny MeSH
- Bacteroidetes izolace a purifikace MeSH
- Dermatophagoides farinae růst a vývoj mikrobiologie MeSH
- Limosilactobacillus fermentum izolace a purifikace MeSH
- mikrobiota * MeSH
- Saccharomyces cerevisiae izolace a purifikace MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Východisko. Hodnocení spotřeby antibiotik a surveillance rezistence bakteriálních původců je nezbytnou součástí tvorby antibiotické politiky. Cílem práce bylo zhodnocení vývoje spotřeby antibiotik a rozvoje rezistence vybraných bakteriálních kmenů (Pseudomonas aeruginosa, Staphylococcus aureus a Staphylococcus epidermidis) v podmínkách fakultní nemocnice. Metody a výsledky. Rozbor se soustředil na vývoj spotřeby antibiotik a na sledování bakteriální rezistence na interní a chirurgické klinice Všeobecné fakultní nemocnice v Praze v letech 1992–1999. Hodnocení spotřeby vycházelo z anatomicko-terapeuticko-chemické klasifikace léčiv a z definovaných denních dávek. Zatímco na chirurgické klinice došlo k nárůstu celkové spotřeby antibiotik přibližně o polovinu, na interní klinice se ve sledovaném období snížila spotřeba téměř o jednu třetinu. Na obou pracovištích, zejména na chirurgické klinice jsme zjistili závažný nárůst bakteriální rezistence k testovaným antibiotikům. Závěry. Sledování vývoje rezistence i spotřeby antibiotik je důležitou součástí místní antibiotické politiky.
Background. Evaluation of antibiotic consumption and the surveillance of bacterial pathogens resistance appears to be an indispensable part of antibiotic policy. The aim of this study was to evaluate dynamics of antibiotics consumption and resistance development in selected bacterial strains (Pseudomonas aueruginosa, Staphylococcus aureus and Staphylococcus epidermidis) in the environment of Faculty Hospital. Methods and Results. The analysis was focused on the development of antibiotic consumption and monitoring of the development of bacterial resistance. Samples were taken in internal and surgical departments of General Faculty Hospital in Prague in 1992, 1995, and 1999. The evaluation of antibiotic consumption was based on Anatomical Therapeutic and Chemical classification system and the Defined Daily Doses (DDD). The consumption in the follow up period almost doubled in surgical department while in internal medicine department was decreased by almost one third. In both department, namely in the surgical one significant increase of bacterial resistance to tested antibiotics was noted. Conclusion. The important part of the local antibiotic policy is the monitoring of development of bacterial resistance and consumption of antibiotics.
Microbial activity in forest soils is driven by the dynamics of ecosystem processes, largely dependent on trees as the major primary producers. Diurnal variation of root activity, seasonality of photosynthate production or recalcitrance of decomposing plant biomass all affect microbial abundance, composition of their communities and activity. Due to low N content, fungi appear to be the major decomposers of complex plant biomass: litter and deadwood and to largely shape associated bacterial communities and their activity. On the other hand, bacteria are important in decomposition of fungal mycelia and N-cycle processes including N-fixation. Microbial activity is also affected in the short term by climatic events and in the long-term by ecosystem development after disturbances.
Mikrobiota osídlující různé tělní oddíly poskytuje za fyziologických podmínek člověku komplexní podporu, která se výrazně podílí na jeho zdraví. Je proto přirozené, že k rozvoji mikrobioty dochází již ve velmi časných fázích ontogenetického vývoje. Přes kontroverznost tvrzení máme jasné důkazy přítomnosti bakterií ve fetálních tkáních ve druhém trimestru intrauterinního vývoje s prokázanou imunitní reakcí plodu na ně. Podstatným pozitivním podnětem pro rozvoj mikrobioty je porod per vaginam a kojení. Tím matka předá kojenci selektivní vzorce své mikrobioty. Prebiotika mateřského mléka stimulují rozvoj mikrobioty trávicí trubice, jejichž definitivní vzor je ovlivněn časově optimálním zařazením pevné stravy. V časném postnatálním období dochází vysoce regulovaně k osídlení ústní dutiny, kůže a dýchacího systému. Dysbiotické osídlovací vzory získané v časném dětství mají nezvratné negativní dopady na zdraví člověka po celý další ontogenetický vývoj.
Microbiota occupying different body compartments under physiological circumstances provides the complex support participating substantially on human health. It is therefore natural that the expansion of microbiota takes place very early during ontogenetic development. Despite some controversy, there is substantial evidence of the presence of bacteria in the tissue of midterm fetuses, with documented immune response to these bacterial stimuli. The optimal stimulus for the development of body microbiota is vaginal birth and breast‐feeding. Selective maternal microbial patterns are transferred to the newborn this way. Mother milk is enriched with prebiotic oligosaccharides, which are essential for the stimulation of gut microbiota of a toddler. The final shape of gut microbiota in a breast‐fed kid very much depends on the optimal timing of solid food introduction. Highly regulated gradual development of oral cavity, respiratory tract and skin microbiota is seen early in the postnatal period. Abnormal dysbiotic microbial patterns gained early in childhood may exert and irreversible negative influence on further ontogenetic development.
The aim of this study was to investigate how the microbial community structure adapts during the start-up phase and how the 13C fractionation of biogas reflects the microbial population dynamics in two parallel swine manure-fed anaerobic digesters. Two swine manure-fed reactors for the start-up of continuously stirred tank reactors at mesophilic condition were evaluated. Changes in community structure were monitored using 16S rRNA high-throughput sequencing to measure the abundance of fermenting bacteria and methanogens. Digesters with relatively stable Methanosarcinaceae started up successfully and contained high gas production and low levels of propionate. In contrast, the digester that experienced a difficult start-up period had reduced Methanosarcinaceae along with accumulated propionate and low gas production. Specific gas production, specific methane production, and 13C fractionation of biogas were influenced significantly by Methanosarcinaceae, Methanobacteriaceae, and Clostridiaceae, indicating that the 13C fractionation of biogas had significant potential to reflect microbial population changes and digester performance during the start-up period.
- MeSH
- anaerobióza MeSH
- Bacteria MeSH
- biopaliva MeSH
- bioreaktory mikrobiologie MeSH
- chemická frakcionace MeSH
- fermentace MeSH
- hnůj mikrobiologie MeSH
- prasata MeSH
- RNA ribozomální 16S genetika MeSH
- uhlík chemie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Small lakes and ponds occupy an enormous surface area of inland freshwater and represent an important terrestrial-water interface. Disturbances caused by extreme weather events can have substantial effects on these ecosystems. Here, we analysed the dynamics of nutrients and the entire plankton community in two flood events and afterwards, when quasi-stable conditions were established, to investigate the effect of such disturbances on a small forest pond. We show that floodings result in repeated washout of resident organisms and hundredfold increases in nutrient load. Despite this, the microbial community recovers to a predisturbance state within two weeks of flooding through four well-defined succession phases. Reassembly of phytoplankton and especially zooplankton takes up to two times longer and features repetitive and adaptive patterns. Release of dissolved nutrients from the pond is associated with inflow rates and community recovery, and returns to predisturbance levels before microbial compositions recover. Our findings shed light on the mechanisms underlying functional resilience of small waterbodies and are relevant to global change-induced increases in weather extremes.
- MeSH
- déšť * MeSH
- extrémní počasí * MeSH
- lesy MeSH
- mikrobiota * MeSH
- plankton růst a vývoj MeSH
- potravní řetězec MeSH
- řeky chemie mikrobiologie MeSH
- rybníky chemie mikrobiologie MeSH
- sladká voda chemie mikrobiologie MeSH
- záplavy MeSH
- živiny analýza MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
