The objectives of this study were (i) to isolate and characterize of cultivable denitrifying bacteria using classic microbiological and molecular methods, (ii) to compare of 16S rRNA and nosZ genes as molecular markers, (iii) to determine bacterial community structure and diversity in soil samples using single-strand conformation polymorphism (SSCP) analysis. In this study, 49 bacterial isolates were cultivated and phylogenetic analyses grouped them into two phyla: Proteobacteria (37 species) and Firmicutes (12 species). Our study showed that the nosZ functional gen could be used to identify denitrifying bacteria abundance in environment but could not be used to identify pure bacterial cultures. In addition, the bacterial community structure showed significant differences among the various soil types. Phylogenetic analysis of community structure indicated that 51 clones could be divided into 2 phylotypes. Uncultured bacteria (80.4%) and Gammaproteobacteria (19.6%) were the dominant components of the soil bacterial community. For 16S rRNA, PCR products of 49 bacteria were obtained with 27F-1492R primer pairs. For nosZ, PCR products were obtained with primers 1F-1R (259 bp), 2F-2R (267 bp), and F-1622R (453 bp) of 39 bacteria that the single nosZ band provided on the agarose gel. The bacterial 16S rRNA gene clone library was dominated by Gammaproteobacteria and Bacilli. The nosZ clone sequences did not represent the bacteria from which they were obtained but were found to be closer to the environmental clones. Our study showed that the nosZ functional gene could be used to identify denitrification abundance in environment but could not be used to identify pure bacterial cultures. It was also found that the nosZ sequences showed uncultured denitrifier species.
- MeSH
- Bacillus klasifikace izolace a purifikace MeSH
- Bacteria klasifikace izolace a purifikace MeSH
- bakteriální geny MeSH
- denitrifikace * MeSH
- DNA bakterií genetika MeSH
- fylogeneze MeSH
- Gammaproteobacteria klasifikace izolace a purifikace MeSH
- mikrobiota * MeSH
- polymorfismus délky restrikčních fragmentů MeSH
- půdní mikrobiologie * MeSH
- RNA ribozomální 16S genetika MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Pectinatella magnifica is a freshwater bryozoan, which has become a subject of scientific interest because of its invasive expansion worldwide. To obtain a comprehensive overview of its influence on environments, information on associated bacteria is needed. In this study, cultivable bacteria associated with P. magnifica were investigated. In total, 253 isolates were selected for preliminary identification by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry and clustered based on repetitive extragenic palindromic-PCR profiles. Among these, 169 strains were selected and identified using 16S rRNA gene comparative analyses. The sequences were grouped into 76 phylotypes and affiliated with 67 species. The majority of isolated bacteria belonged to Gammaproteobacteria, followed by Betaproteobacteria, Firmicutes, Bacteroidetes and Actinobacteria. Most strains within the Betaproteobacteria were isolated exclusively from bryozoan colonies. Aeromonas was the genus predominantly isolated from both P. magnifica and the water samples. Based on 16S rDNA similarity values, 15 putative new species belonging to the genera Aeromonas, Aquitalea, Clostridium, Herbaspirillum, Chromobacterium, Chryseobacterium, Morganella, Paludibacterium, Pectobacterium, Rahnella, Rhodoferax and Serratia, and putative new genera belonging to families Clostridiaceae and Sporomusaceae were revealed. The majority of the detected bacteria were species widely distributed in the environments; nevertheless, a possible symbiotic association of two new putative species with P. magnifica cannot be excluded.
- MeSH
- Betaproteobacteria klasifikace genetika růst a vývoj izolace a purifikace MeSH
- Bryozoa mikrobiologie MeSH
- Firmicutes klasifikace genetika růst a vývoj izolace a purifikace MeSH
- fylogeneze MeSH
- Gammaproteobacteria klasifikace genetika růst a vývoj izolace a purifikace MeSH
- sladká voda mikrobiologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
A spectrogram reflects the arrangement of nucleotides through the whole chromosome or genome. Our previous study suggested that the spectrogram of whole genome DNA sequences is a suitable tool for the determination of relationships among bacteria. Related bacteria have similar spectrograms, and similarity in spectrograms was measured using a color layout descriptor. Several parameters, such as the mapping of four bases into a spectrogram, the number of considered elements in the color layout descriptor, the color model of the image and the building tree method, can be changed. This study addresses the use of parameter selection to ensure the best classification results. The quality of the classification was measured by Matthew's correlation coefficient (MCC). The proposed method with optimal parameters (called SpectCMP-Spectrogram CoMParison method) achieved an average MCC of 0.73 at the phylum level. The SpectCMP method was also tested at the order level; the average MCC in the classification of class Gammaproteobacteria was 0.76. The success of a classification with respect to the correct phyla was compared to three methods that are used in bacterial phylogeny: the CVTree method, OGTree method and moment vector method. The results show that the SpectCMP method can be used in bacterial classification at various taxonomic levels.
The phylogenetic and physiological characteristics of cultivable-dependent approaches were determined to establish the diversity of marine bacteria associated with the intestines of benthonic organisms and seawater samples from the Argentina's Beagle Channel. A total of 737 isolates were classified as psychrophlic and psychrotolerant culturable marine bacteria. These cold-adapted microorganisms are capable of producing cold-active glycosyl hydrolases, such as β-glucosidases, celulases, β-galactosidases, xylanases, chitinases, and proteases. These enzymes could have potential biotechnological applications for use in low-temperature manufacturing processes. According to polymerase chain reaction-restriction fragment length polymorphism analysis of part of genes encoding 16S ribosomal DNA (ARDRA) and DNA gyrase subunit B (gyrB-RFLP), 11 operational taxonomic units (OTU) were identified and clustered in known genera using InfoStat software. The 50 isolates selected were sequenced based on near full sequence analysis of 16S rDNA and gyrB sequences and identified by their nearest neighbors ranging between 96 and 99 % of identities. Phylogenetic analyses using both genes allowed relationships between members of the cultured marine bacteria belonging to the γ-Proteobacteria group (Aeromonas, Halteromonas, Pseudomonas, Pseudoalteromonas, Shewanella, Serratia, Colwellia, Glacielocola, and Psychrobacter) to be evaluated. Our research reveals a high diversity of hydrolytic bacteria, and their products actuality has an industrial use in several bioprocesses at low-temperature manufacturing.
- MeSH
- bakteriální proteiny genetika metabolismus MeSH
- biodiverzita MeSH
- celulasy chemie genetika metabolismus MeSH
- DNA bakterií genetika MeSH
- fylogeneze * MeSH
- Gammaproteobacteria klasifikace enzymologie genetika izolace a purifikace MeSH
- molekulární sekvence - údaje MeSH
- mořská voda mikrobiologie MeSH
- nízká teplota MeSH
- proteasy chemie genetika metabolismus MeSH
- ribozomální DNA genetika MeSH
- RNA ribozomální 16S genetika MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Argentina MeSH
Amoebae play an important ecological role as predators in microbial communities. They also serve as niche for bacterial replication, harbor endosymbiotic bacteria and have contributed to the evolution of major human pathogens. Despite their high diversity, marine amoebae and their association with bacteria are poorly understood. Here we describe the isolation and characterization of two novel marine amoebae together with their bacterial endosymbionts, tentatively named 'Candidatus Occultobacter vannellae' and 'Candidatus Nucleophilum amoebae'. While one amoeba strain is related to Vannella, a genus common in marine habitats, the other represents a novel lineage in the Amoebozoa. The endosymbionts showed only low similarity to known bacteria (85-88% 16S rRNA sequence similarity) but together with other uncultured marine bacteria form a sister clade to the Coxiellaceae. Using fluorescence in situ hybridization and transmission electron microscopy, identity and intracellular location of both symbionts were confirmed; one was replicating in host-derived vacuoles, whereas the other was located in the perinuclear space of its amoeba host. This study sheds for the first time light on a so far neglected group of protists and their bacterial symbionts. The newly isolated strains represent easily maintainable model systems and pave the way for further studies on marine associations between amoebae and bacterial symbionts.
- MeSH
- Amoeba klasifikace mikrobiologie MeSH
- buněčné jádro mikrobiologie MeSH
- cytoplazma mikrobiologie MeSH
- druhová specificita MeSH
- Gammaproteobacteria klasifikace izolace a purifikace fyziologie MeSH
- symbióza fyziologie MeSH
- vodní organismy klasifikace izolace a purifikace mikrobiologie MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
We present a fascinating triad relationship between a eukaryotic amoeba and its two bacterial symbionts. The morphological characteristics of the amoeba allowed for a confident assignment to the genus Nuclearia (Opisthokonta, Nucleariidae), but species identification resulted in an ambiguous result. Sequence analysis indicated an affiliation to the species N. thermophila, however, several morphological features contradict the original description. Amoebal isolates were cultured for several years with their preferred food source, the microcystin-producing harmful cyanobacterium Planktothrix rubescens. Symbioses of the amoeba with ecto- and endosymbiotic bacteria were maintained over this period. Several thousand cells of the ectosymbiont are regularly arranged inside a layer of extracellular polymeric substances produced by the amoeba. The ectosymbiont was identified as Paucibacter toxinivorans (Betaproteobacteria), which was originally isolated by enrichment with microcystins. We found indications that our isolated ectosymbiont indeed contributed to toxin-degradation. The endosymbiont (Gammaproteobacteria, 15-20 bacteria per amoeba) is enclosed in symbiosomes inside the host cytoplasm and represents probably an obligate symbiont. We propose the name "Candidatus Endonucleariobacter rarus" for this bacterium that was neither found free-living nor in a symbiotic association. Nucleariidae are uniquely suited model organisms to study the basic principles of symbioses between opisthokonts and prokaryotes.
- MeSH
- Amoeba klasifikace cytologie izolace a purifikace mikrobiologie MeSH
- Betaproteobacteria klasifikace izolace a purifikace fyziologie MeSH
- DNA bakterií chemie genetika MeSH
- Gammaproteobacteria klasifikace izolace a purifikace fyziologie MeSH
- geny rRNA MeSH
- jezera parazitologie MeSH
- mezerníky ribozomální DNA chemie genetika MeSH
- molekulární sekvence - údaje MeSH
- protozoální DNA chemie genetika MeSH
- ribozomální DNA chemie genetika MeSH
- RNA protozoální genetika MeSH
- RNA ribozomální 16S genetika MeSH
- RNA ribozomální 18S genetika MeSH
- sekvenční analýza DNA MeSH
- symbióza * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Švýcarsko MeSH
Morphologically similar microbial communities that often form on the walls of geographically distinct limestone caves have not yet been comparatively studied. Here, we analysed phylotype distribution in yellow microbial community samples obtained from the walls of distinct caves located in Spain, Czech Republic and Slovenia. To infer the level of similarity in microbial community membership, we analysed inserts of 474 16S rRNA gene clones and compared those using statistical tools. The results show that the microbial communities under investigation are composed solely of Bacteria. The obtained phylotypes formed three distinct groups of operational taxonomic units (OTUs). About 60% of obtained sequences formed three core OTUs common to all three sampling sites. These were affiliated with actinobacterial Pseudonocardinae (30-50% of sequences in individual sampling site libraries), but also with gammaproteobacterial Chromatiales (6-25%) and Xanthomonadales (0.5-2.0%). Another 7% of sequences were common to two sampling sites and formed eight OTUs, while the remaining 35% were site specific and corresponded mostly to OTUs containing single sequences. The same pattern was observed when these data were compared with sequence data available from similar studies. This comparison showed that distinct limestone caves support microbial communities composed mostly of phylotypes common to all sampling sites.
- MeSH
- Bacteria klasifikace genetika izolace a purifikace MeSH
- fylogeneze MeSH
- Gammaproteobacteria klasifikace genetika izolace a purifikace MeSH
- geny rRNA MeSH
- jeskyně mikrobiologie MeSH
- RNA ribozomální 16S genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
- Slovinsko MeSH
- Španělsko MeSH
Aerobic bacterial strains from the salt water of Lake Red (Sovata, Romania) were cultivated. More than half of the 80 strains were G(-) and formed motile straight rods. Only a few strains produced acid from D-glucose and reduced nitrate to nitrite. Optimum NaCl concentration for growth varied between 5 and 15 % in the majority of the strains, so the isolates were regarded moderately halophilic. On the basis of the 16S rRNA gene sequence similarity almost half of the strains were identified as members of genus Halomonas. Other strains belonged to genera Marinobacter, Psychrobacter, Serratia, Morganella (?-Proteobacteria), Bacillus, Exiguobacterium, Planococcus (Firmicutes), and Arthrobacter, Micrococcus, Microbacterium, and Nesterenkonia (Actinobacteria).
- MeSH
- Actinobacteria genetika izolace a purifikace klasifikace metabolismus MeSH
- aerobní bakterie genetika izolace a purifikace klasifikace metabolismus MeSH
- biodiverzita MeSH
- chlorid sodný MeSH
- DNA bakterií genetika MeSH
- fenotyp MeSH
- fylogeneze MeSH
- Gammaproteobacteria genetika izolace a purifikace klasifikace metabolismus MeSH
- Halomonas genetika izolace a purifikace klasifikace metabolismus MeSH
- kultivační média MeSH
- plankton růst a vývoj MeSH
- počet mikrobiálních kolonií MeSH
- RNA ribozomální 16S genetika MeSH
- sekvenční analýza DNA MeSH
- sladká voda chemie mikrobiologie MeSH
- Geografické názvy
- Rumunsko MeSH
