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The interaction of warming and soil texture on responsiveness of the key soil processes i.e. organic carbon (C) fractions, soil microbes, extracellular enzymes and CO2 emissions remains largely unknown. Global warming raises the relevant question of how different soil processes will respond in near future, and what will be the likely regulatory role of texture? To bridge this gap, this work applied the laboratory incubation method to investigate the effects of temperature changes (10-50 °C) on dynamics of labile, recalcitrant and stable C fractions, soil microbes, microbial biomass, activities of extracellular enzymes and CO2 emissions in sandy and clayey textured soils. The role of texture (sandy and clayey) in the mitigation of temperature effect was also investigated. The results revealed that the temperature sensitivity of C fractions and extracellular enzymes was in the order recalcitrant C fractions > stable C fractions > labile C fractions and oxidative enzymes > hydrolytic enzymes. While temperature sensitivity of soil microbes and biomass was in the order bacteria > actinomycetes > fungi ≈ microbial biomass C (MBC) > microbial biomass N (MBN) > microbial biomass N (MBP). Conversely, the temperature effect and sensitivity of all key soil processes including CO2 emissions were significantly (P < 0.05) higher in sandy than clayey textured soil. Results confirmed that under the scenario of global warming and climate change, soils which are sandy in nature are more susceptible to temperature increase and prone to become the CO2-C sources. It was revealed that clayey texture played an important role in mitigating and easing off the undue temperature influence, hence, the sensitivity of key soil processes.
- Klíčová slova
- CO2 fluxes, Extracellular enzymes, Soil C fractions, Soil microbes and biomass, Temperature sensitivity, Texture,
- MeSH
- jíl MeSH
- oxid uhličitý * analýza MeSH
- písek MeSH
- půda * MeSH
- půdní mikrobiologie MeSH
- teplota MeSH
- uhlík MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- jíl MeSH
- oxid uhličitý * MeSH
- písek MeSH
- půda * MeSH
- uhlík MeSH
Pelagic microbes have adopted distinct strategies to inhabit the pelagial of lakes and oceans and can be broadly categorized in two groups: free-living, specialized oligotrophs and patch-associated generalists or copiotrophs. In this review, we aim to identify genomic traits that enable pelagic freshwater microbes to thrive in their habitat. To do so, we discuss the main genetic differences of pelagic marine and freshwater microbes that are both dominated by specialized oligotrophs and the difference to freshwater sediment microbes, where copiotrophs are more prevalent. We phylogenomically analysed a collection of >7700 metagenome-assembled genomes, classified habitat preferences on different taxonomic levels, and compared the metabolic traits of pelagic freshwater, marine, and freshwater sediment microbes. Metabolic differences are mainly associated with transport functions, environmental information processing, components of the electron transport chain, osmoregulation and the isoelectric point of proteins. Several lineages with known habitat transitions (Nitrososphaeria, SAR11, Methylophilaceae, Synechococcales, Flavobacteriaceae, Planctomycetota) and the underlying mechanisms in this process are discussed in this review. Additionally, the distribution, ecology and genomic make-up of the most abundant freshwater prokaryotes are described in details in separate chapters for Actinobacteriota, Bacteroidota, Burkholderiales, Verrucomicrobiota, Chloroflexota, and 'Ca. Patescibacteria'.
- MeSH
- Bacteria genetika MeSH
- ekologie * MeSH
- ekosystém MeSH
- fylogeneze MeSH
- genomika MeSH
- jezera * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Biomolecules for OMIC analysis of microbial communities are commonly extracted by bead-beating or ultra-sonication, but both showed varying yields. In addition to that, different disruption pressures are necessary to lyse bacteria and fungi. However, the disruption efficiency and yields comparing bead-beating and ultra-sonication of different biological material have not yet been demonstrated. Here, we show that ultra-sonication in a bath transfers three times more energy than bead-beating over 10 min. TEM imaging revealed intact gram-positive bacterial and fungal cells whereas the gram-negative bacterial cells were destroyed beyond recognition after 10 min of ultra-sonication. DNA extraction using 10 min of bead-beating revealed higher yields for fungi but the extraction efficiency was at least three-fold lower considering its larger genome. By our critical viewpoint, we encourage the review of the commonly used extraction techniques as we provide evidence for a potential underrepresentation of resistant microbes, particularly fungi, in ecological studies.
- MeSH
- Bacteria genetika MeSH
- bakteriální léková rezistence genetika MeSH
- bakteriální proteiny chemie izolace a purifikace MeSH
- DNA bakterií genetika MeSH
- DNA chemie izolace a purifikace MeSH
- fungální léková rezistence genetika MeSH
- fungální proteiny chemie izolace a purifikace MeSH
- houby genetika MeSH
- mikrosféry MeSH
- vibrace ultrazvukové metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Názvy látek
- bakteriální proteiny MeSH
- DNA bakterií MeSH
- DNA MeSH
- fungální proteiny MeSH
The aim of this work was to test the hypothesis that antimicrobial food additives may alter the composition of human gut microbiota by selectively suppressing the growth of susceptible gut microbes. To explore the influence of antimicrobial food additives on the composition of the human gut microbiota, we examined the susceptibility of both aerobic and anaerobic gut bacteria to sodium benzoate, sodium nitrite, and potassium sorbate, and their combinations, using a broth microdilution method. The tested bacteria exhibited a wide range of susceptibilities to food additives. For example, the most susceptible strain, Bacteroides coprocola, was almost 580 times more susceptible to sodium nitrite than the most resistant strain, Enterococcus faecalis. However, most importantly, we found that gut microbes with known anti-inflammatory properties, such as Clostridium tyrobutyricum or Lactobacillus paracasei, were significantly more susceptible to additives than microbes with known proinflammatory or colitogenic properties, such as Bacteroides thetaiotaomicron or Enterococcus faecalis. Our data show that some human gut microbes are highly susceptible to antimicrobial food additives. We speculate that permanent exposure of human gut microbiota to even low levels of additives may modify the composition and function of gut microbiota and thus influence the host's immune system. Whether the effect of additive-modified gut microbiota on the human immune system could explain, at least in part, the increasing incidence of allergies and autoimmune diseases remains to be shown.
- Klíčová slova
- Autoimmune diseases, Chou-Talalay method, Dysbiosis, Food additives, Gut microbiota, Mucosal immunology,
- MeSH
- antibakteriální látky farmakologie MeSH
- gastrointestinální trakt imunologie mikrobiologie MeSH
- lidé MeSH
- potravinářské přísady farmakologie MeSH
- střevní mikroflóra účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antibakteriální látky MeSH
- potravinářské přísady MeSH
Thanks to modern molecular biology methods, our understanding of the impact of (endo)symbiotic bacteria on parasitic protists and helminths is growing fast. In this issue, 9 papers have been brought together that describe various facets of the relationships between these microorganisms, reveal their range and high frequency, as well as their capacity to create novel biological complexity. Comparative analyses of these host-endosymbiont interactions indicate that there may be no discrete types of relationships but rather a continuum ranging from a dispensable endosymbiont minimally integrated within the host cell to organelles, such as mitochondria and plastids that evolved into an indispensable, deeply integrated components of the cell. We hope that this series of studies on parasites and (endo)symbiotic bacteria will increase awareness about these relationships and their representation in microbial ecology models.
- Klíčová slova
- Endosymbiont, microbiome, organelle, protist, symbiosis,
- MeSH
- biologická evoluce MeSH
- organely MeSH
- paraziti mikrobiologie MeSH
- symbióza * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- úvodníky MeSH
Insects nurture a panoply of microbial populations that are often obligatory and exist mutually with their hosts. Symbionts not only impact their host fitness but also shape the trajectory of their phenotype. This co-constructed niche successfully evolved long in the past to mark advanced ecological specialization. The resident microbes regulate insect nutrition by controlling their host plant specialization and immunity. It enhances the host fitness and performance by detoxifying toxins secreted by the predators and abstains them. The profound effect of a microbial population on insect physiology and behaviour is exploited to understand the host-microbial system in diverse taxa. Emergent research of insect-associated microbes has revealed their potential to modulate insect brain functions and, ultimately, control their behaviours, including social interactions. The revelation of the gut microbiota-brain axis has now unravelled insects as a cost-effective potential model to study neurodegenerative disorders and behavioural dysfunctions in humans. This article reviewed our knowledge about the insect-microbial system, an exquisite network of interactions operating between insects and microbes, its mechanistic insight that holds intricate multi-organismal systems in harmony, and its future perspectives. The demystification of molecular networks governing insect-microbial symbiosis will reveal the perplexing behaviours of insects that could be utilized in managing insect pests.
- Klíčová slova
- arthropod vector, detoxification, gut microbiome, holobiont, host immunity, insect symbiosis, nutrition provisioning, omics technology,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Protein production must be strictly controlled at its beginning and end to synthesize a polypeptide that faithfully copies genetic information carried in the encoding mRNA. In contrast to viruses and prokaryotes, the majority of mRNAs in eukaryotes contain only one coding sequence, resulting in production of a single protein. There are, however, many exceptional mRNAs that either carry short open reading frames upstream of the main coding sequence (uORFs) or even contain multiple long ORFs. A wide variety of mechanisms have evolved in microbes and higher eukaryotes to prevent recycling of some or all translational components upon termination of the first translated ORF in such mRNAs and thereby enable subsequent translation of the next uORF or downstream coding sequence. These specialized reinitiation mechanisms are often regulated to couple translation of the downstream ORF to various stimuli. Here we review all known instances of both short uORF-mediated and long ORF-mediated reinitiation and present our current understanding of the underlying molecular mechanisms of these intriguing modes of translational control.
- MeSH
- Bacteria genetika metabolismus MeSH
- Eukaryota genetika MeSH
- lidé MeSH
- otevřené čtecí rámce genetika MeSH
- proteosyntéza genetika fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, N.I.H., Intramural MeSH
- Klíčová slova
- ESCHERICHIA COLI *, SPERMATOZOA *, STAPHYLOCOCCUS *,
- MeSH
- Escherichia coli * MeSH
- lidé MeSH
- spermicidy * MeSH
- spermie * MeSH
- Staphylococcus * MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- spermicidy * MeSH
The gut microbes, collectively called microbiota, are linked to the brain through a bidirectional system that involves the vagus nerve, the immune system, and various neurotransmitters. Stress response, memory functions, social behavior, and mood are modulated by microbiota. Furthermore, microbiota play a role in the development of the central nervous system. These features, established largely in rodent studies, have informed hypotheses about the role of microbiota in human psychiatric disorders. Microbiota affect phenomena that are known to be parts of the depression phenotype, such as exaggerated response to stress and inflammatory features. Furthermore, the role of microbiota in neurodevelopment and in the modulation of social behavior suggests the possibility of its role in autism spectrum disorder and in schizophrenia. If altered, microbiota play a role in psychiatric disorders, then efforts to normalize the gut microbial population by the ingestion of probiotics (live bacteria) could have antidepresssant or antipsychotic effects. Testing such hypotheses in translational human studies is a matter of future research.
- MeSH
- depresivní poruchy farmakoterapie mikrobiologie patofyziologie MeSH
- duševní poruchy farmakoterapie mikrobiologie patofyziologie MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- mozek účinky léků patofyziologie MeSH
- neurovývojové poruchy farmakoterapie mikrobiologie patofyziologie MeSH
- obsedantně kompulzivní porucha farmakoterapie mikrobiologie patofyziologie MeSH
- probiotika terapeutické užití MeSH
- střevní mikroflóra účinky léků fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Plant beneficial microbes (PBMs), such as plant growth-promoting bacteria, rhizobia, arbuscular mycorrhizal fungi, and Trichoderma, can reduce the use of agrochemicals and increase plant yield, nutrition, and tolerance to biotic-abiotic stresses. Yet, large-scale applications of PBM have been hampered by the high amounts of inoculum per plant or per cultivation area needed for successful colonization and consequently the economic feasibility. Seed coating, a process that consists in covering seeds with low amounts of exogenous materials, is gaining attention as an efficient delivery system for PBM. Microbial seed coating comprises the use of a binder, in some cases a filler, mixed with inocula, and can be done using simple mixing equipment (e.g., cement mixer) or more specialized/sophisticated apparatus (e.g., fluidized bed). Binders/fillers can be used to extend microbial survival. The most reported types of seed coating are seed dressing, film coating, and pelleting. Tested in more than 50 plant species with seeds of different dimensions, forms, textures, and germination types (e.g., cereals, vegetables, fruits, pulses, and other legumes), seed coating has been studied using various species of plant growth-promoting bacteria, rhizobia, Trichoderma, and to a lesser extent mycorrhizal fungi. Most of the studies regarding PBM applied via seed coating are aimed at promoting crop growth, yield, and crop protection against pathogens. Studies have shown that coating seeds with PBM can assist crops in improving seedling establishment and germination or achieving high yields and food quality, under reduced chemical fertilization. The right combination of biological control agents applied via seed coating can be a powerful tool against a wide number of diseases and pathogens. Less frequently, studies report seed coating being used for adaptation and protection of crops under abiotic stresses. Notwithstanding the promising results, there are still challenges mainly related with the scaling up from the laboratory to the field and proper formulation, including efficient microbial combinations and coating materials that can result in extended shelf-life of both seeds and coated PBM. These limitations need to be addressed and overcome in order to allow a wider use of seed coating as a cost-effective delivery method for PBM in sustainable agricultural systems.
- Klíčová slova
- Trichoderma, arbuscular mycorrhizal fungi, plant growth-promoting bacteria, rhizobia, seed coating, sustainable agriculture,
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH