Current models predict increases in High Arctic temperatures and precipitation that will have profound impacts on the Arctic hydrological cycle, including enhanced glacial melt and thawing of active layer soils. However, it remains uncertain how these changes will impact the structure of downstream resident freshwater microbial communities and ensuing microbially driven freshwater ecosystem services. Using the Lake Hazen watershed (Nunavut, Canada; 82°N, 71°W) as a sentinel system, we related microbial community composition (16S rRNA gene sequencing) to physicochemical parameters (e.g. dissolved oxygen and nutrients) over an annual hydrological cycle in three freshwater compartments within the watershed: (i) glacial rivers; (ii) active layer thaw-fed streams and waterbodies and (iii) Lake Hazen, into which (i) and (ii) drain. Microbial communities throughout these freshwater compartments were strongly interconnected, hydrologically, and often correlated with the presence of melt-sourced chemicals (e.g. dissolved inorganic carbon) as the melt season progressed. Within Lake Hazen itself, water column microbial communities were generally stable over spring and summer, despite fluctuating lake physicochemistry, indicating that these communities and the potential ecosystem services they provide therein may be resilient to environmental change. This work helps to establish a baseline understanding of how microbial communities and the ecosystem services they provide in Arctic watersheds might respond to future climate change.

• Klíčová slova
• Arctic, Lake Hazen, biogeochemistry, freshwaters, glacial rivers, microbial ecology, soil active layer streams, watersheds,
• MeSH
• ekosystém MeSH
• jezera mikrobiologie   MeSH
• klimatické změny MeSH
• mikrobiologie vody * MeSH
• mikrobiota * MeSH
• půda MeSH
• půdní mikrobiologie MeSH
• řeky mikrobiologie   MeSH
• RNA ribozomální 16S MeSH
• roční období MeSH
• sladká voda mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Arktida MeSH
• Nunavut MeSH
• Názvy látek
• půda MeSH
• RNA ribozomální 16S MeSH

Soil from Trhové Dušníky (Příbram, Czech Republic) is characterized by its high polymetallic accumulations in Pb-Ag-Zn due to mining and smelting activities. In previous studies performed in our research group, we have evaluated the potential use of amendments that would reduce the mobility and availability of metals such as Hg. We have observed that the application of digestate and fly ash in metal-polluted soil has an impact in immobilizing these metals. However, until now we have lacked information about the effect of these amendments on soil microbial functionality and communities. The multi-contaminated soil was used to grow wheat in a pot experiment to evaluate the impact of digestate and fly ash application in soil microbial communities. Soil samples were collected after 30 and 60 days of treatment. The digestate application improved chemical attributes such as the content in total organic carbon (TOC), water soluble carbon (WSOC), total soluble carbon (C), total soluble nitrogen (N), and inorganic N forms (NO3(-)) as consequence of high content in C and N which is contained in digestate. Likewise, microbial activity was greatly enhanced by digestate application, as was physiological diversity. Bacterial and fungal communities were increased, and the microbial biomass was highly enhanced. These effects were evident after 30 and 60 days of treatment. In contrast, fly ash did not have a remarkable effect when compared to digestate, but soil microbial biomass was positively affected as a consequence of macro- and micro-nutrient sources applied by the addition of fly ash. This study indicates that digestate can be used successfully in the remediation of metal-contaminated soil.

• Klíčová slova
• Amendments, Communities structure, Microbial biomass, Microbial functionality, Physiological diversity, Soil pollution,
• MeSH
• biomasa MeSH
• dusík analýza   MeSH
• hornictví MeSH
• houby fyziologie   MeSH
• kovy analýza   metabolismus   MeSH
• látky znečišťující půdu analýza   metabolismus   MeSH
• mikrobiální společenstva MeSH
• popel uhelný * MeSH
• pšenice růst a vývoj   MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• rtuť analýza   metabolismus   MeSH
• uhlík analýza   chemie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• dusík MeSH
• kovy MeSH
• látky znečišťující půdu MeSH
• popel uhelný * MeSH
• půda MeSH
• rtuť MeSH
• uhlík MeSH

Understanding the ecology of coniferous forests is very important because these environments represent globally largest carbon sinks. Metatranscriptomics, microbial community and enzyme analyses were combined to describe the detailed role of microbial taxa in the functioning of the Picea abies-dominated coniferous forest soil in two contrasting seasons. These seasons were the summer, representing the peak of plant photosynthetic activity, and late winter, after an extended period with no photosynthate input. The results show that microbial communities were characterized by a high activity of fungi especially in litter where their contribution to microbial transcription was over 50%. Differences in abundance between summer and winter were recorded for 26-33% of bacterial genera and < 15% of fungal genera, but the transcript profiles of fungi, archaea and most bacterial phyla were significantly different among seasons. Further, the seasonal differences were larger in soil than in litter. Most importantly, fungal contribution to total microbial transcription in soil decreased from 33% in summer to 16% in winter. In particular, the activity of the abundant ectomycorrhizal fungi was reduced in winter, which indicates that plant photosynthetic production was likely one of the major drivers of changes in the functioning of microbial communities in this coniferous forest.

• MeSH
• Archaea klasifikace   genetika   MeSH
• Bacteria klasifikace   genetika   MeSH
• borovicovité mikrobiologie   MeSH
• ekosystém MeSH
• fotosyntéza MeSH
• genetická transkripce genetika   MeSH
• houby klasifikace   genetika   MeSH
• lesy MeSH
• messenger RNA biosyntéza   genetika   MeSH
• mikrobiota genetika   MeSH
• mykorhiza MeSH
• půda MeSH
• půdní mikrobiologie * MeSH
• roční období MeSH
• stanovení celkové genové exprese MeSH
• stromy mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• půda MeSH

Forests are essential biomes for global biogeochemical cycles, and belowground microorganisms have a key role in providing relevant ecosystem services. To predict the effects of environmental changes on these ecosystem services requires a comprehensive understanding of how biotic and abiotic factors drive the composition of microbial communities in soil. However, microorganisms are not homogeneously distributed in complex environments such as soil, with different features affecting microbes at different extent depending on the niche they occupy. Indeed, this spatial heterogeneity hampers the extrapolation of microbial diversity study results from particular habitats to the ecosystem level, even if the resolution of the more recent studies has increased significantly after the standardization of high-throughput sequencing techniques. The present work intends to give a comprehensive view of the knowledge accumulated until date defining the more important drivers determining the structure of forest soil microbial communities from fine to continental scales.

• Klíčová slova
• Community structure, Drivers, Forest, Microbial diversity, Soil,
• MeSH
• Bacteria MeSH
• ekosystém * MeSH
• lesy * MeSH
• mikrobiota fyziologie   MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• půda MeSH

The aims of this study were to determine the microbial community in five rivers in the proximity of a city in the Czech Republic using 454-pyrosequencing, as well as to assess seasonal variability over the course of 1 year and to identify the factors influencing the structure of bacterial communities. Samples from five rivers around the city of Brno were obtained during four seasons and analysed using 454 pyrosequencing of the 16S rRNA gene. The core composition of bacterial communities consisted of Actinobacteria, Bacteroidetes, Proteobacteria, Firmicutes, Fusobacteria, TM7 and others. Our approach enabled us to more closely study the correlation between the abundance of different families and environmental factors. Overall, Actinobacteria negatively correlated with phosphorus, sulphate, dissolved particle and chloride levels. In contrast, Proteobacteria positively correlated with sulphate, dissolved particle, chloride, dissolved oxygen and nitrite levels. Future work should focus on the dynamics of bacterial communities present in river water and their relation to the overall stability of the water ecosystem.

• Klíčová slova
• Environmental factors, Microbial community, Pyrosequencing, River water,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: The application of a biochar in agronomical soil offers a dual benefit of improving soil quality and sustainable waste recycling. However, utilizing new organic waste sources requires exploring the biochar's production conditions and application parameters. Woodchips (W) and bone-meat residues (BM) after mechanical deboning from a poultry slaughterhouse were subjected to pyrolysis at 300 °C and 500 °C and applied to cambisol and luvisol soils at ratios of 2% and 5% (w/w). RESULTS: Initially, the impact of these biochar amendments on soil prokaryotes was studied over the course of one year. The influence of biochar variants was further studied on prokaryotes and fungi living in the soil, rhizosphere, and roots of Triticum aestivum L., as well as on soil enzymatic activity. Feedstock type, pyrolysis temperature, application dose, and soil type all played significant roles in shaping both soil and endophytic microbial communities. BM treated at a lower pyrolysis temperature of 300 °C increased the relative abundance of Pseudomonadota while causing a substantial decrease in soil microbial diversity. Conversely, BM prepared at 500 °C favored the growth of microbes known for their involvement in various nutrient cycles. The W biochar, especially when pyrolysed at 500 °C, notably affected microbial communities, particularly in acidic cambisol compared to luvisol. In cambisol, biochar treatments had a significant impact on prokaryotic root endophytes of T. aestivum L. Additionally, variations in prokaryotic community structure of the rhizosphere depended on the increasing distance from the root system (2, 4, and 6 mm). The BM biochar enhanced the activity of acid phosphatase, whereas the W biochar increased the activity of enzymes involved in the carbon cycle (β-glucosidase, β-xylosidase, and β-N-acetylglucosaminidase). CONCLUSIONS: These results collectively suggest, that under appropriate production conditions, biochar can exert a positive influence on soil microorganisms, with their response closely tied to the biochar feedstock composition. Such insights are crucial for optimizing biochar application in agricultural practices to enhance soil health.

• Klíčová slova
• Biochar, Enzymatic activity, Microbial composition, Organic waste recycling, Soil quality,
• Publikační typ
• časopisecké články MeSH

The rhizosphere is the hotspot for microbial enzyme activities and contributes to carbon cycling. Precipitation is an important component of global climate change that can profoundly alter belowground microbial communities. However, the impact of precipitation on conifer rhizospheric microbial populations has not been investigated in detail. In the present study, using high-throughput amplicon sequencing, we investigated the impact of precipitation on the rhizospheric soil microbial communities in two Norway Spruce clonal seed orchards, Lipová Lhota (L-site) and Prenet (P-site). P-site has received nearly double the precipitation than L-site for the last three decades. P-site documented higher soil water content with a significantly higher abundance of Aluminium (Al), Iron (Fe), Phosphorous (P), and Sulphur (S) than L-site. Rhizospheric soil metabolite profiling revealed an increased abundance of acids, carbohydrates, fatty acids, and alcohols in P-site. There was variance in the relative abundance of distinct microbiomes between the sites. A higher abundance of Proteobacteria, Acidobacteriota, Ascomycota, and Mortiellomycota was observed in P-site receiving high precipitation, while Bacteroidota, Actinobacteria, Chloroflexi, Firmicutes, Gemmatimonadota, and Basidiomycota were prevalent in L-site. The higher clustering coefficient of the microbial network in P-site suggested that the microbial community structure is highly interconnected and tends to cluster closely. The current study unveils the impact of precipitation variations on the spruce rhizospheric microbial association and opens new avenues for understanding the impact of global change on conifer rizospheric microbial associations.

• Klíčová slova
• FUNGuild, Norway spruce, PICRUSt2, amplicon sequencing, microbial communities, network analysis, precipitation, rhizosphere, seed orchards, soil metabolites,
• MeSH
• Bacteria genetika   klasifikace   metabolismus   MeSH
• déšť MeSH
• klimatické změny MeSH
• mikrobiota * genetika   MeSH
• půda chemie   MeSH
• půdní mikrobiologie * MeSH
• rhizosféra * MeSH
• semena rostlinná růst a vývoj   mikrobiologie   MeSH
• smrk * mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• půda MeSH

Fifty-six calves in the period of a milk nutrition, randomly assigned to two groups (control and alpha amylase fed) were used to monitor the changes in the rumen microbial populations and total volatile fatty acids (VFA) concentrations associated with feeding Amylosubtilin G10X (0.6 g.day-1). Statistically significant increase was observed for amylolytic counts in experimental calves on 20th or 30th days. The counts of rumen cellulolytic bacteria and selenomonas tended to have increase in the value, but were not significantly different from those in the control valves. The results show that alpha amylase fed calves has a relative higher rumen microbial population.

• MeSH
• alfa-amylasy aplikace a dávkování   MeSH
• bachor mikrobiologie   MeSH
• Bacteria růst a vývoj   MeSH
• dieta * MeSH
• skot mikrobiologie   MeSH
• zvířata MeSH
• Check Tag
• skot mikrobiologie   MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-amylasy MeSH

Genomic reorganisation between species and horizontal gene transfer have been considered the most important mechanism of biological adaptation under selective pressure. Still, the impact of mobile genes in microbial ecology is far from being completely understood. Here we present the collection and characterisation of microbial consortia enriched from environments contaminated with emerging pollutants, such as non-steroidal anti-inflammatory drugs. We have obtained and further enriched two ibuprofen-degrading microbial consortia from two unrelated wastewater treatment plants. We have also studied their ability to degrade the drug and the dynamics of the re-organisations of the genetic information responsible for its biodegradation among the species within the consortium. Our results show that genomic reorganisation within microorganisms and species rearrangements occur rapidly and efficiently during the selection process, which may be facilitated by plasmids and/or transposable elements located within the sequences. We show the evolution of at least two different plasmid backbones on samples from different locations, showing rearrangements of genomic information, including genes encoding activities for IBU degradation. As a result, we found variations in the expression pattern of the consortia after evolution under selective pressure, as an adaptation process to the new conditions. This work provides evidence for changes in the metagenomes of microbial communities that allow adaptation under a selective constraint -ibuprofen as a sole carbon source- and represents a step forward in knowledge that can inspire future biotechnological developments for drug bioremediation.

• Klíčová slova
• biodegradation, consortia evolution, emerging pollutants, ibuprofen, microbial ecology,
• MeSH
• Bacteria genetika   metabolismus   klasifikace   MeSH
• biodegradace * MeSH
• genová přestavba MeSH
• ibuprofen * metabolismus   MeSH
• metagenom MeSH
• mikrobiální společenstva * genetika   MeSH
• odpadní voda mikrobiologie   MeSH
• plazmidy * genetika   MeSH
• přenos genů horizontální MeSH
• transpozibilní elementy DNA MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ibuprofen * MeSH
• odpadní voda MeSH
• transpozibilní elementy DNA MeSH

The growth and survival of plants in semiarid Mediterranean forests can be improved through the benefits conferred by thinning, a forest management practice that removes trees and reduces the competition between the remaining ones. Here, we evaluate the impacts of induced drought (the exclusion of 25% of the natural rainfall for 5 years) and thinning, and their interaction, with the objective of determining whether the thinning of Holm oak (Quercus ilex L.) modulates the resistance of the soil microbial community to drought. Sequencing of 16S rRNA and ITS amplicons revealed that drought, thinning, and their interaction influenced the composition of the bacterial community, while the fungal community was exclusively affected by thinning. Thinning consisted of the removal of the aboveground parts of the Holm oak trees, which were thereafter left in forest stand. Thinning contributed to the C and N contents, with parallel increases in microbial biomass, particularly in summer. Drought increased the amounts of total organic C and total N, likely due to the reduced enzyme activities. Indeed, the composition of the bacterial community was modulated primarily by the indirect and long-term effects of drought - the accumulation of soil organic matter - rather than by the direct effect of the lower water content imposed by the drought treatments. Thinning under drought conditions did not increase soil organic C (SOC) content. However, the resistance of the soil microbial community to drought was fostered by thinning, particularly at the functional level, as indicated by the enzyme activities related to C, N and P cycles. These responses were associated to variations in the composition of the microbial communities in thinned, drought-exposed plots, in comparison to unthinned, drought-exposed plots. In conclusion, the interaction between forest management and drought influenced the soil microbial community of a Holm oak-dominated Mediterranean ecosystem.

• Klíčová slova
• Drought, Enzyme activity, Holm oak, Semiarid, Soil microbial community, Thinning,
• MeSH
• Bacteria MeSH
• biomasa MeSH
• dub (rod) růst a vývoj   MeSH
• houby MeSH
• klimatické změny * MeSH
• lesnictví metody   MeSH
• lesy * MeSH
• mikrobiota * MeSH
• období sucha * MeSH
• půdní mikrobiologie * MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Španělsko MeSH