V přírodě rostou mikroby většinou v podobě biofilmu. Biofilm je strukturované mikrobiální společenství, uložené v mezibuněčné hmotě a adherující k inertním i živým povrchům. Mikrobiální buňky rostoucí v podobě biofilmu se svými vlastnostmi zásadně liší od volně se vznášejících buněk planktonických, především jsou vysoce odolné k zevním vlivům. Popsán je vývoj biofilmu a jeho architektura. Biofilmy představují vyšší a složitější způsob života mikrobů a jsou analogií tkání vyšších organismů. Vykazují totiž 1. účinnou homeostázu, 2. prvky primitivního oběhového systému, 3. rysy buněčné kooperace a specializace a 4. značný způsob ochrany před antimikrobiálními činiteli.Povědomí o biofilmu proniká do lékařské mikrobiologie pomalu, i když platí, že bakterie v biofilmu jsou až o tři řády odolnější k účinku antibiotik než buňky planktonické. Uvedeny jsou příklady chronických a perzistentních infekcí, v jejichž patogenezi se významně uplatňuje biofilm vznikající jak na přirozeném povrchu tkání, tak na neživém povrchu různých pomůcek a náhrad zaváděných do makroorganismu. Naznačeny jsou cesty k terapeutickému ovlivnění biofilmu a je zdůrazněna prospěšná role biofilmu v ochraně sliznic před patogeny.
In natural environment, microbes grow mostly in the form of a biofilm. Biofilm is a structured microbial community placed in an extracellular matrix and adhering to both inert and live surfaces. Microbial cells growing as a biofilm have qualities fundamentally different from those of freely floating planctonic cells, in the first place they are extremely resistant to outer influences. The development and the architecture of the biofilm are described. Biofilms represent a higher and more complex mode of microbial life and are an analogy of tissues of higher organisms. They are characterised by 1. an effective homeostasis, 2. components of a primitive circulatory system, 3. elements of cellular cooperation and specialization, and 4. a considerable way of protection against antimicrobial agents. The awareness of the biofilm penetrates only slowly into medical microbiology, even though it has been known that bacteria in the biofilm are as much as a thousand timesmore resistant to the effect of antibiotics than planctonic cells. Examples of chronic and persistent infections are given, in the pathogenesis of which a significant role is played by the biofilm, growing both on the natural surface of tissues and on the inert surface of different devices and prostheses inserted into the macrooganism. Possible ways to the therapeutic tampering with the biofilm are foreshadowed and the beneficial role of the biofilm in the protection of mucosal surfaces against pathogens is emphasized.
- MeSH
- Drug Resistance, Microbial MeSH
- Bacterial Adhesion MeSH
- Biofilms microbiology MeSH
- Publication type
- Review MeSH
Peatland vegetation is composed mostly of mosses, graminoids and ericoid shrubs, and these have a distinct impact on peat biogeochemistry. We studied variation in soil microbial communities related to natural peatland microhabitats dominated by Sphagnum, cotton-grass and blueberry. We hypothesized that such microhabitats will be occupied by structurally and functionally different microbial communities, which will vary further during the vegetation season due to changes in temperature and photosynthetic activity of plant dominants. This was addressed using amplicon-based sequencing of prokaryotic and fungal rDNA and qPCR with respect to methane-cycling communities. Fungal communities were highly microhabitat-specific, while prokaryotic communities were additionally directed by soil pH and total N content. Seasonal alternations in microbial community composition were less important; however, they influenced the abundance of methane-cycling communities. Cotton-grass and blueberry bacterial communities contained relatively more α-Proteobacteria but less Chloroflexi, Fibrobacteres, Firmicutes, NC10, OD1 and Spirochaetes than in Sphagnum. Methanogens, syntrophic and anaerobic bacteria (i.e. Clostridiales, Bacteroidales, Opitutae, Chloroflexi and Syntrophorhabdaceae) were suppressed in blueberry indicating greater aeration that enhanced abundance of fungi (mainly Archaeorhizomycetes) and resulted in the highest fungi-to-bacteria ratio. Thus, microhabitats dominated by different vascular plants are inhabited by unique microbial communities, contributing greatly to spatial functional diversity within peatlands.
- MeSH
- Bacteria classification genetics isolation & purification metabolism MeSH
- Blueberry Plants growth & development microbiology MeSH
- Fungi classification genetics isolation & purification metabolism MeSH
- Poaceae growth & development microbiology MeSH
- Methane metabolism MeSH
- Microbiota MeSH
- Soil chemistry MeSH
- Soil Microbiology * MeSH
- Sphagnopsida growth & development microbiology MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, N.I.H., Extramural MeSH
Plant and microbial community composition in connection with soil chemistry determines soil nutrient cycling. The study aimed at demonstrating links between plant and microbial communities and soil chemistry occurring among and within four sites: two pine forests with contrasting soil pH and two grasslands of dissimilar soil chemistry and vegetation. Soil was characterized by C and N content, particle size, and profiles of low-molecular-weight compounds determined by high-performance liquid chromatography (HPLC) of soil extracts. Bacterial and actinobacterial community composition was assessed by terminal restriction fragment length polymorphism (T-RFLP) and cloning followed by sequencing. Abundances of bacteria, fungi, and actinobacteria were determined by quantitative PCR. In addition, a pool of secondary metabolites was estimated by erm resistance genes coding for rRNA methyltransferases. The sites were characterized by a stable proportion of C/N within each site, while on a larger scale, the grasslands had a significantly lower C/N ratio than the forests. A Spearman's test showed that soil pH was correlated with bacterial community composition not only among sites but also within each site. Bacterial, actinobacterial, and fungal abundances were related to carbon sources while T-RFLP-assessed microbial community composition was correlated with the chemical environment represented by HPLC profiles. Actinobacteria community composition was the only studied microbial characteristic correlated to all measured factors. It was concluded that the microbial communities of our sites were influenced primarily not only by soil abiotic characteristics but also by dominant litter quality, particularly, by percentage of recalcitrant compounds.
- MeSH
- Bacteria classification genetics isolation & purification MeSH
- Bacterial Load MeSH
- Biodiversity MeSH
- DNA, Bacterial chemistry genetics MeSH
- Nitrogen analysis MeSH
- Phylogeny MeSH
- Fungi classification genetics isolation & purification MeSH
- Hydrogen-Ion Concentration MeSH
- Methyltransferases genetics MeSH
- Molecular Sequence Data MeSH
- Organic Chemicals analysis MeSH
- Colony Count, Microbial MeSH
- Polymorphism, Restriction Fragment Length MeSH
- Soil chemistry MeSH
- Soil Microbiology MeSH
- Plants microbiology MeSH
- Sequence Analysis, DNA MeSH
- Cluster Analysis MeSH
- Carbon analysis MeSH
- Chromatography, High Pressure Liquid MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
One of the universal traits of microorganisms is their ability to form multicellular structures, the cells of which differentiate and communicate via various signaling molecules. Reactive oxygen species (ROS), and hydrogen peroxide in particular, have recently become well-established signaling molecules in higher eukaryotes, but still little is known about the regulatory functions of ROS in microbial structures. Here we summarize current knowledge on the possible roles of ROS during the development of colonies and biofilms, representatives of microbial multicellularity. In Saccharomyces cerevisiae colonies, ROS are predicted to participate in regulatory events involved in the induction of ammonia signaling and later on in programmed cell death in the colony center. While the latter process seems to be induced by the total ROS, the former event is likely to be regulated by ROS-homeostasis, possibly H(2)O(2)-homeostasis between the cytosol and mitochondria. In Candida albicans biofilms, the predicted signaling role of ROS is linked with quorum sensing molecule farnesol that significantly affects biofilm formation. In bacterial biofilms, ROS induce genetic variability, promote cell death in specific biofilm regions, and possibly regulate biofilm development. Thus, the number of examples suggesting ROS as signaling molecules and effectors in the development of microbial multicellularity is rapidly increasing.
Earthworms and their casts have been widely used for organic waste degradation and plant growth promotion. The microbial communities that reside in the guts and casts of earthworms markedly influence both applications. In the present study, next-generation sequencing was applied to identify the microbial communities in the guts and casts of three epigeic earthworm species, Eudrilus eugeniae, Perionyx excavatus, and Eisenia fetida, reared under two different feeding conditions. A total of 580 genera belonging to 43 phyla were identified. By comparing bacterial diversity among samples divided into groups based on the earthworm species, sample types, and conditions, the beta diversity analysis supported the impact of the sample type and suggested that there was significant dissimilarity of the bacterial diversity between the gut and cast. Besides, bacterial Phylum compositions within the group were compared. The result showed that the top three high relative frequency phyla found in the casts were the same regardless of earthworm species, while those found in the gut depended on both the condition and earthworm species. Focusing on the cellulolytic and plant growth-promoting bacteria, certain cellulolytic bacteria, Paenibacillus, Comamonas, and Cytophaga, were found only in the cast. Citrobacter and Streptomyces aculeolatus were detected only in the guts of earthworms reared in the bedding containing vegetables and bedding alone, respectively. Besides, Actinomadura and Burkholderia were detected only in the gut of E. eugeniae and E. fetida, respectively. The results proved that the microbial composition was affected by sample type, condition, and earthworm species. In addition, the proportion of these beneficial bacteria was also influenced by these factors. Hence, the information from this study can be used as a guide for selecting earthworm species or their casts for more efficient organic waste decomposition and plant growth promotion.
- MeSH
- Bacteria genetics MeSH
- Microbiota * MeSH
- Oligochaeta * microbiology MeSH
- Soil MeSH
- Gastrointestinal Microbiome * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article 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
- Rain * MeSH
- Extreme Weather * MeSH
- Forests MeSH
- Microbiota * MeSH
- Plankton growth & development MeSH
- Food Chain MeSH
- Rivers chemistry microbiology MeSH
- Ponds chemistry microbiology MeSH
- Fresh Water chemistry microbiology MeSH
- Floods MeSH
- Nutrients analysis MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Nitrogen leaching owing to elevated acid deposition remains the main ecosystem threat worldwide. We aimed to contribute to the understanding of the highly variable nitrate losses observed in Europe after acid deposition retreat. Our study proceeded in adjacent beech and spruce forests undergoing acidification recovery and differing in nitrate leaching. We reconstructed soil microbial functional characteristics connected with nitrogen and carbon cycling based on community composition. Our results showed that in the more acidic spruce soil with high carbon content, where Acidobacteria and Actinobacteria were abundant (Proteo:Acido = 1.3), the potential for nitrate reduction and loss via denitrification was high (denitrification: dissimilative nitrogen reduction to ammonium (DNRA) = 3). In the less acidic beech stand with low carbon content, but high nitrogen availability, Proteobacteria were more abundant (Proteo:Acido = 1.6). Proportionally less nitrate could be denitrified there (denitrification:DNRA = 1), possibly increasing its availability. Among 10 potential keystone species, microbes capable of DNRA were identified in the beech soil while instead denitrifiers dominated in the spruce soil. In spite of the former acid deposition impact, distinct microbial functional guilds developed under different vegetational dominance, resulting in different N immobilization potentials, possibly influencing the ecosystem's nitrogen retention ability.
- MeSH
- Bacteria classification metabolism MeSH
- Fagus growth & development MeSH
- Denitrification * MeSH
- Nitrates analysis MeSH
- Hydrogen-Ion Concentration MeSH
- Microbiota * MeSH
- Soil chemistry MeSH
- Soil Microbiology * MeSH
- Picea growth & development MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Europe MeSH
Microbial ecology has been recognized as useful in archaeological studies. At Archaic Monte Iato in Western Sicily, a native (indigenous) building was discovered. The objective of this study was the first examination of soil microbial communities related to this building. Soil samples were collected from archaeological layers at a ritual deposit (food waste disposal) in the main room and above the fireplace in the annex. Microbial soil characterization included abundance (cellular phospholipid fatty acids (PLFA), viable bacterial counts), activity (physiological profiles, enzyme activities of viable bacteria), diversity, and community structure (bacterial and fungal Illumina amplicon sequencing, identification of viable bacteria). PLFA-derived microbial abundance was lower in soils from the fireplace than in soils from the deposit; the opposite was observed with culturable bacteria. Microbial communities in soils from the fireplace had a higher ability to metabolize carboxylic and acetic acids, while those in soils from the deposit metabolized preferentially carbohydrates. The lower deposit layer was characterized by higher total microbial and bacterial abundance and bacterial richness and by a different carbohydrate metabolization profile compared to the upper deposit layer. Microbial community structures in the fireplace were similar and could be distinguished from those in the two deposit layers, which had different microbial communities. Our data confirmed our hypothesis that human consumption habits left traces on microbiota in the archaeological evidence; therefore, microbiological residues as part of the so-called ecofacts are, like artifacts, key indicators of consumer behavior in the past.
- MeSH
- Acetates metabolism MeSH
- Archaeology * MeSH
- Bacteria classification genetics isolation & purification metabolism MeSH
- Bacterial Load MeSH
- Biodiversity MeSH
- Biomass MeSH
- History, Ancient MeSH
- DNA, Bacterial MeSH
- DNA, Fungal MeSH
- Enzyme Assays MeSH
- Phospholipids metabolism MeSH
- Heterotrophic Processes MeSH
- Fungi classification genetics metabolism MeSH
- Carboxylic Acids metabolism MeSH
- Human Activities history MeSH
- Fatty Acids metabolism MeSH
- Microbial Consortia genetics physiology MeSH
- Soil chemistry MeSH
- Soil Microbiology * MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Cluster Analysis MeSH
- Check Tag
- History, Ancient MeSH
- Publication type
- Journal Article MeSH
- Historical Article MeSH
The North of Romania is known for its wooden churches dating from the seventeenth and eighteenth centuries. Their deterioration constitutes a major problem due to their value for the cultural heritage. The microbial community from a seventeenth-century wooden church (Nicula, Romania) was investigated by characterization of uncultivated and cultivated bacteria using 16S rDNA sequence analysis. The study revealed not only the prevalence of the Bacillus thuringiensis strain IAM 12077 but also the presence of new microbial communities of Planomicrobium and Variovorax that were not previously reported in paintings or on wood. The identification of fungi showed the presence of seven common genera found on the walls and icon surfaces. Common bacteria from the human oral microbiota were not identified in the bacterial community.
- MeSH
- Bacteria classification genetics isolation & purification MeSH
- DNA, Bacterial chemistry genetics MeSH
- DNA, Fungal chemistry genetics MeSH
- Wood microbiology MeSH
- Fungi classification genetics isolation & purification MeSH
- Humans MeSH
- Environmental Microbiology * MeSH
- Molecular Sequence Data MeSH
- DNA, Ribosomal chemistry genetics MeSH
- Sequence Analysis, DNA MeSH
- Biota * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Romania MeSH
