Obtaining full-length 16S rRNA gene sequences is important for generating accurate taxonomy assignments of bacteria, which normally is realized via clone library construction. However, the application of clone library has been hindered due to its limitations in sample throughput and in capturing minor populations (<1 % of total microorganisms). To overcome these limitations, a new strategy, two-step denaturing gradient gel electrophoresis (2S-DGGE), is developed to obtain full-length 16S rRNA gene sequences. 2S-DGGE can compare microbial communities based on its first-round DGGE profiles and generate partial 16S rRNA gene sequences (8-534 bp, Escherichia coli numbering). Then, strain-specific primers can be designed based on sequence information of bacteria of interest to PCR amplify their remaining 16S rRNA gene sequences (515-1541 bps, E. coli numbering). The second-round DGGE can confirm DNA sequence purity of these PCR products. Finally, the full-length 16S rRNA gene sequences can be ...
Two Gram-stain-positive, aerobic, pink, curved, rod-shaped, non-motile bacterial strains, designated MI-28T and SKY-11, were isolated from freshwater samples taken from a river and fish pond, respectively. Based on characterization using a polyphasic approach, the two strains showed highly similar phenotypic, physiological and genetic profiles. They demonstrated 99.9 % 16S rRNA gene sequence similarity and a 93-95 % DNA-DNA relatedness value, suggesting that they represent a single genomic species. Phylogenetic analyses, based on 16S rRNA gene sequences, showed that strains MI-28T and SKY-11 form a distinct lineage with respect to closely related genera within the family Microbacteriaceae of the class Actinobacteria , which is most closely related to Rhodoluna and Pontimonas, and levels of 16S rRNA gene sequence similarity with the type species of related genera were less than 95 %. Cell-wall analysis showed that the peptidoglycan contained 2,4-diaminobutyric acid, alanine, glycine and glutamic acid.
A novel Ferrimonas species is described on the basis of phenotypic, chemotaxonomic and phylogenetic studies. Four halophilic organisms were isolated from marine sand and marine macroalgae samples by using high-pH marine agar 2216. An analysis of the nearly complete 16S rRNA gene sequences of these new isolates indicated that they were phylogenetically close (16S rRNA gene sequence similarity |99·5 %, gyrB gene sequence similarity |97·8 %), and were most closely related to Ferrimonas balearica (16S rRNA gene sequence similarity 97·1-97·3 %, gyrB gene sequence similarity 84·4-85·0 %). Chemotaxonomic data (major menaquinone MK7; major fatty acids C16 : 0 and C18 : 1 ω9c) supported the affiliation of the new isolates to the genus Ferrimonas. The results of physiological and biochemical tests allowed phenotypic differentiation of the isolates from F. balearica. It is therefore proposed that the new isolates represent a novel species with the name Ferrimonas marina sp. nov. and type strain A4D-4T (
A Gram-positive, motile, round to ellipsoidal, endospore-forming, rod-shaped bacterial strain, SF-57T, was isolated from a marine solar saltern in Korea. This organism grew between 4 and 39 °C, with optimum growth at 30 °C. Strain SF-57T grew in the presence of 0·5-15·0 % NaCl, with optimum growth at 2-3 % NaCl. The peptidoglycan type of strain SF-57T was A1α linked directly through l-Lys. In strain SF-57T, menaquinone-7 (MK-7) was the predominant isoprenoid quinone and anteiso-C15 : 0 was the major fatty acid. The DNA G+C content was 41·8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain SF-57T formed a coherent cluster with Marinibacillus marinus, with a bootstrap resampling value of 100 %. The level of 16S rRNA gene sequence similarity between strain SF-57T and M. marinus DSM 1297T was 98·9 %. The mean DNA-DNA relatedness level between strain SF-57T and the type strain of M. marinus was 20·6 %. Based on phenotypic properties, phylogenetic analyses and genomic
A Gram-stain-positive, aerobic, non-motile, rod-shaped bacterium, strain 0704C9-2T, was isolated from hydrothermal sediment of the Indian Ocean. The organism grew with 0-5 % (w/v) NaCl and at 10-37 °C, with optimal growth occurring with 1 % NaCl and at 28-30 °C. Comparative 16S rRNA gene sequence analysis revealed that strain 0704C9-2T belonged to the genus Microbacterium . It exhibited highest 16S rRNA gene sequence similarity with Microbacterium testaceum DSM 20166T (98.4 %). Levels of similarity with the type strains of all other recognized species of the genus Microbacterium were less than 98.0 %. DNA-DNA hybridization experiments with strain 0704C9-2T and its closest relative, M. testaceum DSM 20166T, revealed a low reassociation value of 42.9 %. The DNA G+C content of strain 0704C9-2T was 73.3 mol%. The cell-wall peptidoglycan contained ornithine and the acyl type was glycolyl. The major whole-cell sugars were mannose, galactose, rhamnose and glucose. The major cellular fatty acids were
Over a period of ten months a total of 5618 cord blood units (CBU) were screened for microbial contamination under routine conditions. The antibiotic resistance profile for all isolates was also examined using ATB strips. The detection rate for culture positive units was 7.5%, corresponding to 422 samples.16S rRNA sequence analysis and identification with API test system were used to identify the culturable aerobic, microaerophilic and anaerobic bacteria from CBUs. From these samples we recovered 485 isolates (84 operational taxonomic units, OTUs) assigned to the classes Bacteroidia, Actinobacteria, Clostridia, Bacilli, Betaproteobacteria and primarily to the Gammaproteobacteria. Sixty-nine OTUs, corresponding to 447 isolates, showed 16S rRNA sequence similarities above 99.0% with known cultured bacteria. However, 14 OTUs had 16S rRNA sequence similarities between 95 and 99% in support of genus level identification and one OTU with 16S rRNA sequence similarity of 90.3% supporting a family level
INTRODUCTION. The genus Bacillus is a phenotypically large, diverse collection of Gram-positive or Gram-variable staining, endospore-forming, aerobic or facultatively anaerobic, rod-shaped bacteria that have undergone considerable reclassification as advances in molecular biology have revealed a high phylogenetic heterogeneity (5, 21). The genus Bacillus and related genera are distributed widely in nature and include thermophilic, psychrophilic, acidophilic, alkalophilic and halophilic bacteria that utilize a wide range of carbon sources for heterotrophic growth or grow autotrophically.. The investigations on phylogenetic divergence of the genus Bacillus and its mesophilic and thermophilic members indicated the need for further and extensive studies to place some of these bacilli in appropriate taxonomic levels (1, 23, 21). With the accumulation of further 16S rRNA gene sequence data, Bacillus has been divided into more manageable and better-defined groups (16). According to Ludwig et al. (2007) ...
Background. 16S rRNA gene sequences are routinely assigned to operational taxonomic units (OTUs) that are then used to analyze complex microbial communities. A number of methods have been employed to carry out the assignment of 16S rRNA gene sequences to OTUs leading to confusion over which method is the most rigorous. A recent study suggested that a clustering method should be selected based on its ability to generate stable OTU assignments that do not change as additional sequences are added to the dataset. In contrast, we contend that the ability of the method to properly represent the distances between the sequences is more important. Methods. Our analysis implemented five de novo clustering algorithms including the single linkage, complete linkage, average linkage, abundance-based greedy clustering, distance-based greedy clustering, and the open and closed-reference methods. Using two previously published datasets we used the Matthews Correlation Coefficient (MCC) to assess the stability and
1), metal-rich acid mine drainage habitats in the Richmond Mine at Iron Mountain, Calif., we detected 16S rRNA gene sequences of a novel bacterial group belonging to the order Rickettsiales in the Alphaproteobacteria. The closest known relatives of this group (92% 16S rRNA gene sequence identity) are endosymbionts of the protist Acanthamoeba. Oligonucleotide 16S rRNA probes were designed and used to observe members of this group within acidophilic protists. To improve visualization of eukaryotic populations in the acid mine drainage samples, broad-specificity probes for eukaryotes were redesigned and combined to highlight this component of the acid mine drainage community. Approximately 4% of protists in the acid mine drainage samples contained endosymbionts. Measurements of internal pH of the protists showed that their cytosol is close to neutral, indicating that the endosymbionts may be neutrophilic. The endosymbionts had a conserved 273-nucleotide intervening sequence (IVS) in variable region ...
The recent development of methods applying next-generation sequencing to microbial community characterization has led to the proliferation of these studies in a wide variety of sample types. Yet, variation in the physical properties of environmental samples demands that optimal DNA extraction techniques be explored for each new environment. The microbiota associated with many species of insects offer an extraction challenge as they are frequently surrounded by an armored exoskeleton, inhibiting disruption of the tissues within. In this study, we examine the efficacy of several commonly used protocols for extracting bacterial DNA from ants. While bacterial community composition recovered using Illumina 16S rRNA amplicon sequencing was not detectably biased by any method, the quantity of bacterial DNA varied drastically, reducing the number of samples that could be amplified and sequenced. These results indicate that the concentration necessary for dependable sequencing is around 10,000 copies of ...
A bacterial strain, B5-2(T), was isolated from an ice core drilled from Muztagh Glacier, China. Strain B5-2(T) was a Gram-stainnegative, short rod-shaped, motile by polar flagella, aerobic bacterium. The major fatty acids of strain B5-2(T) were summed feature 8 (C-18 : 1 omega 7c and/ or C-18 : 1 omega 6c) and iso-C-13 : 0. The G+C content of the DNA from strain B5-2(T) was 69.3 mol%. The predominant isoprenoid quinone of strain B5-2(T) was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidyldimethylethanolamine, phosphatidylcholine, an unidentified phospholipid and sulfoquinovosyldiacylglycerol. Comparative 16S rRNA gene sequence analysis revealed that the novel strain B5-2(T) shared highest similarity (96.7 %) with Aureimonas altamirensis S21B(T). On the basis of the results of this polyphasic study, strain B5-2(T) represents a novel species of the genus Aureimonas, for which the name Aureimonas glaciei sp. nov. is ...
Community Structure, Diversity, and Vertical Distribution of Archaea Revealed by 16S rRNA Gene Analysis in the Deep Sea Sediment of the Ulleung Basin, East Sea - archaeal diversity;16S rRNA gene;marine group;Ulleung Basin;East Sea;
In a recent study, rich clinical assessment and longitudinal study design are combined with host gene expression and microbial sequencing analyses to develop a framework for exploring disease etiology and outcomes in the context of human inflammatory disease. See related article: http://dx.doi.org/10.1186/s13059-015-0637-x
An obligately aerobic, chemoheterotrophic, mesophilic prosthecate bacterium, designated strain CGM1-3ENT, was isolated from the enrichment cultures of forest soil from Cheonggyesan Mountain, Republic of Korea. Cells were Gram-reaction-negative, motile rods (1.3–2.4 µm long by 0.30–0.75 µm wide) with single flagella. The strain grew at 10–37 °C (optimum 25–30 °C) and at pH 4.5–9.5 (optimum 5.0–7.0). The major cellular fatty acids were C16 : 0, C18 : 1ω7c 11-methyl, C12 : 1 3-OH and summed feature 8 (comprising C18 : 1ω7c/C18 : 1ω6c). The genomic DNA G+C content of strain CGM1-3ENT was 63.7 mol%. The closest phylogenetic neighbour to strain CGM1-3ENT was identified as Asticcacaulis biprosthecium DSM 4723T (97.2 % 16S rRNA gene sequence similarity) and the DNA–DNA hybridization value between strain CGM1-3ENT and A. biprosthecium DSM 4723T was less than 24.5 %. Strain ...
16S rRNA amplicon analysis and shotgun metagenome sequencing are two main culture-independent strategies to explore the genetic landscape of various microbial communities. Recently, numerous studies have employed these two approaches together, but downstream data analyses were performed separately, which always generated incongruent or conflict signals on both taxonomic and functional classifications. Here we propose a novel approach, RiboFR-Seq (Ribosomal RNA gene flanking region sequencing), for capturing both ribosomal RNA variable regions and their flanking protein-coding genes simultaneously. Through extensive testing on clonal bacterial strain, salivary microbiome and bacterial epibionts of marine kelp, we demonstrated that RiboFR-Seq could detect the vast majority of bacteria not only in well-studied microbiomes but also in novel communities with limited reference genomes. Combined with classical amplicon sequencing and shotgun metagenome sequencing, RiboFR-Seq can link the annotations of 16S
The PyroTRF-ID bioinformatics methodology (http://bbcf.epfl.ch/PyroTRF-ID/) was developed to combine pyrosequencing and T-RFLP for describing microbial communities and identifying T-RFs by comparison of experimental and digital T-RFLP profiles obtained from the same biological samples. DNA extracts were subjected to amplification of the 16S rRNA gene pool, T-RFLP with the HaeIII restriction enzyme, 454 tag encoded FLX amplicon pyrosequencing, and PyroTRF-ID analysis. Digital T-RFLP profiles were generated from the denoised pyrosequencing datasets. Sequences contributing to each digital T-RF were classified to taxonomic bins using the Greengenes reference database. The method was tested on bacterial communities found in chloroethene-contaminated groundwater samples and in granular biofilms from lab-scale wastewater treatment systems. PyroTRF-ID was efficient for high-throughput mapping and digital T-RFLP profiling of pyrosequencing datasets. After denoising, multiple datasets comprising ca. ...
Objectives Dysbiosis of the intestinal microbiota is associated with Crohns disease (CD). Functional evidence for a causal role of bacteria in the development of chronic small intestinal inflammation is lacking. Similar to human pathology, TNFdeltaARE mice develop a tumour necrosis factor (TNF)-driven CD-like transmural inflammation with predominant ileal involvement. Design Heterozygous TNFdeltaARE mice and wildtype (WT) littermates were housed under conventional (CONV), specific pathogen-free (SPF) and germ-free (GF) conditions. Microbial communities were analysed by high-throughput 16S ribosomal RNA gene sequencing. Metaproteomes were measured using LC-MS. Temporal and spatial resolution of disease development was followed after antibiotic treatment and transfer of microbial communities into GF mice. Granulocyte infiltration and Paneth cell function was assessed by immunofluorescence and gene expression analysis. Results GF-TNFdeltaARE mice were free of inflammation in the gut and antibiotic ...
View more ,A new extremely halophilic chemoorganotrophic bacterium (strain H200T [T = type strain]) was isolated from the hypersaline sediments of Retba Lake in Senegal. This organism was a sluggishly motile, rod-shaped, non-spore-forming, gram-negative, obligate anaerobe that grew optimally at 40 degrees C in the presence of 180 to 200 g of NaCl per liter. The DNA base composition was 32 mol% guanine plus cytosine. The fermentation products from glucose were ethanol, acetate, H2, and CO2. Yeast extract was required for growth. The fermentable substrates included D-fructose, galactose, D-xylose, cellobiose, lactose, maltose, sucrose, starch, D-mannitol, glycerol, and Casamino Acids. On the basis of the results of a 16S rRNA sequence analysis, strain H200T was found to be related to Haloanaerobium species. The 16S rRNA sequence of strain H200T differed from the sequences of the three previously described Haloanaerobium species, and strain H200T also differed from these organisms in its NaCl range ...
The appeal of using MinION for 16S rRNA sequencing is the portability, the potential to get near full-length 16S rRNA reads, and the ability for rapid (same day) sequence data. The capital costs are also low (a laptop), which is a step forward in the democratization of sequencing. While there are many potential applications, some may include sample screening prior to sequencing on another platform, sequencing in the field, or sequencing in the clinic for patient monitoring. The obvious challenge is the error rate.. To initially evaluate the potential of this technology, we sequenced 16S rRNA sequences from pure-culture E. coli and P. fluorescens, as well as a low-diversity sample from hydraulic fracturing produced water that we had previously analyzed using Illumina sequencing. We actually evaluated many more samples, but were forced to exclude them due to sample carryover between washes, which I discuss below.. We attempted to cluster the pure-culture reads into Operational Taxonomic Units ...
Bacterial community composition, as revealed by deep 16S sequence analyses, is argued to contribute to diverse human health and disease states (10). While the microbial community structure has been shown to influence susceptibility to infection in models of gastrointestinal disease (2, 4, 5, 34), the application of this concept to the female urinary tract has not been pursued. To define the existence and compositions of bladder bacterial communities in human females without the confounding factor of possible vulvo-vaginal contamination, we carefully sampled urine directly from female bladders using TUC and SPA. Deep 16S rRNA gene sequencing of these samples revealed that bacterial bladder communities of different types do exist in women, although not in all individuals. These data confirm and extend results of earlier studies (17, 21-23), clearly showing that urine specimens reported to clinicians as culture-negative or insignificant growth can contain varied bacterial communities that can ...
Widdel 1981) Kuever 2006 may be the type and only species of the genus and the order GEBAproject. class represents a separate lineage within the which is only distantly related to most other members of this class. The closest relatives based on 16S rRNA gene sequence similarity values are the type strains of (87.6% sequence identity) and (87.2%) both belonging to the family within the order [9]. The most similar cloned 16S rRNA gene EUB-42 [10] shared only 95.5% sequence similarity with and was retrieved from anaerobic sludge. Strain 2st14T WYE-354 represents the only stress of this varieties obtainable from a tradition collection so far. Available data from cultivation 3rd party studies (environmental testing and genomic studies) didnt surpass 86% series similarity indicating that people of this varieties are limited to specific habitats which are undersampled generally in most conditions or are in low great quantity (status Oct 2010). The solitary genomic 16S rRNA series of stress 2st14T was ...
Strains VIM M 10366(T), YIM M 10378(T) and YIM M 10400(T) were isolated from marine sediments collected from the Xisha Islands in the South China Sea. All three isolates were able to grow optimally at pH 7.0, 28-37 degrees C and 0-3% (w/v) NaCl. Comparison of 16S rRNA gene sequences showed that these strains are members of the genus Streptomyces, exhibiting moderately high 16S rRNA gene sequence similarities of 97.0-98.8% to members of the most closely related Streptomyces species. Morphological characteristics, physiological characteristics and compositions of whole-cell sugars and phospholipids are consistent with the diagnostic characteristics of the genus Streptomyces, but still allowed differentiation amongst the three strains and their neighbours. Based on 16S rRNA gene sequence analysis, DNA DNA relatedness, phenotypic characteristics and chemotaxonomic data, strains VIM M 10366(T), VIM M 10378(T) and VIM M 10400(T) were identified as members of three novel species of the genus ...
A Gram-stain-positive, aerobic, non-spore-forming, atrichous and short rod-shaped endophytic actinomycete, designated strain BGMRC 2075 , was isolated from the leaves of Kandelia candel, and was subjected to polyphasic characterization to unravel its taxonomic position. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain BGMRC 2075 belongs to the genus Nocardioides ,showing the highest 16S rRNA gene sequence similarity to Nocardioides aestuarii JC2056 (96.1 %), Nocardioides agariphilus MSL-28 (95.1 %) andNocardioides islandiensis MSL-26 (95.1 %). The predominant cellular fatty acids of strain BGMRC 2075 were iso-C16 : 0, C17 : 1ω8c and C17 : 0. The major menaquinone was MK-8(H4). The diagnostic diamino acid in the cell-wall peptidoglycan was ll-2,6-diaminopimelic acid. The predominant cell-wall sugars were composed of ribose and glucose. The polar lipid pattern contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylcholine, ...
A Gram-staining-positive, cocci, halotolerant bacterial strain, designated as SV-16T, was isolated from marine sediment and subjected to a polyphasic taxonomic study. The strain exhibited phenotypic properties that included chemotaxonomic characteristics consistent with its classification in the genus Salinicoccus. Growth occurs at temperatures in the range between 25-37 °C (optimum 30 °C), pH 7.0-11.0 (optimum 8.0) and at NaCl concentrations up to 25 .0 % (optimum 15.0 %). The highest level of 16S rRNA gene sequence similarity was with Salinicoccus carnicancri CrmT (98.6 %) followed by Salinicoccus halodurans W24T (96.6 %). The predominant polar lipids are diphosphatidylglycerol (DPG), phosphatidylinositol (PI) and phosphatidylglycerol (PG). The major cellular fatty acids are iso-C15: 0, anteiso-C15: 0, iso-C17: 0 and anteiso C17: 0. The draft genome of strain SV-16T consisted of 2,591,284 bp with G+C content of 48.7 mol %. On the basis of the phenotypic characteristics and genotypic ...
Background Next-generation sequencing platforms have revolutionised our ability to investigate the microbiota composition of complex environments, frequently through 16S rRNA gene sequencing of the bacterial component of the community. Numerous factors, including DNA extraction method, primer sequences and sequencing platform employed, can affect the accuracy of the results achieved. The aim of this study was to determine the impact of these three factors on 16S rRNA gene sequencing results, using mock communities and mock community DNA. Results The use of different primer sequences (V4-V5, V1-V2 and V1-V2 degenerate primers) resulted in differences in the genera and species detected. The V4-V5 primers gave the most comparable results across platforms. The three Ion PGM primer sets detected more of the 20 mock community species than the equivalent MiSeq primer sets. Data generated from DNA extracted using the 2 extraction methods were very similar. Conclusions Microbiota compositional data ...
article{7225551, abstract = {A Gram-stain-positive, ovoid, lactic acid bacterium, strain LMG 27676(T), was isolated from a spoiled sous-vide-cooked rutabaga. 16S rRNA gene sequence analysis indicated that the novel strain belongs to the genus Leuconostoc, with Leuconostoc kimchii and Leuconostoc miyukkimchii as the nearest neighbours (99.1 and 98.8\% 16S rRNA gene sequence similarity towards the type strain, respectively). Phylogenetic analysis of the 16S rRNA gene, multilocus sequence analysis of the pheS, rpoA and atpA genes, and biochemical and genotypic characteristics allowed differentiation of strain LMG 27676(T) from all established species of the genus Leuconostoc. Strain LMG 27676(T) (=R-50029(T)=MHB 277(T)=DSM 27776(T)) therefore represents the type strain of a novel species, for which the name Leuconostoc rapi sp. nov. is proposed.}, author = {Lyhs, Ulrike and Snauwaert, Isabel and Pihlajaviita, Seija and De Vuyst, Luc and Vandamme, Peter}, issn = {1466-5026}, journal = {INTERNATIONAL ...
Globally, marine surface sediments constitute a habitat for estimated 1.7 × 1028 prokaryotes. For benthic microbial community analysis, usually, several grams of sediment are processed. In this study, we made the step from bulk sediments to single sand grains to address the microbial community directly in its micro-habitat: the individual bacterial diversity on 17 sand grains was analyzed by 16S ribosomal RNA gene sequencing and visualized on sand grains using catalyzed reporter deposition fluorescence in situ hybridization. In all, 104-105 cells were present on grains from 202 to 635 μm diameter. Colonization was patchy, with exposed areas largely devoid of any epi-growth (mean cell-cell distance 4.5±5.9 μm) and protected areas more densely populated (0.5±0.7 μm). Mean cell-cell distances were 100-fold shorter compared with the water column. In general, growth occurred in monolayers. Each sand grain harbors a highly diverse bacterial community as shown by several thousand species-level
Multiyear comparisons of bacterioplankton succession reveal that environmental conditions drive community shifts with repeatable patterns between years. However, corresponding insight into bacterioplankton dynamics at a temporal resolution relevant for detailed examination of variation and characteristics of specific populations within years is essentially lacking. During 1 year, we collected 46 samples in the Baltic Sea for assessing bacterial community composition by 16S rRNA gene pyrosequencing (nearly twice weekly during productive season). Beta-diversity analysis showed distinct clustering of samples, attributable to seemingly synchronous temporal transitions among populations (populations defined by 97% 16S rRNA gene sequence identity). A wide spectrum of bacterioplankton dynamics was evident, where divergent temporal patterns resulted both from pronounced differences in relative abundance and presence/absence of populations. Rates of change in relative abundance calculated for individual ...
Terminal restriction fragment length polymorphism (TRFLP or sometimes T-RFLP) is a molecular biology technique for profiling of microbial communities based on the position of a restriction site closest to a labelled end of an amplified gene. The method is based on digesting a mixture of PCR amplified variants of a single gene using one or more restriction enzymes and detecting the size of each of the individual resulting terminal fragments using a DNA sequencer. The result is a graph image where the x-axis represents the sizes of the fragment and the y-axis represents their fluorescence intensity. TRFLP is one of several molecular methods aimed to generate a fingerprint of an unknown microbial community. Other similar methods include DGGE, TGGE, ARISA, ARDRA, PLFA, etc. These relatively high throughput methods were developed in order to reduce the cost and effort in analyzing microbial communities using a clone library. The method was first described by Liu and colleagues in 1997 which employed ...
A polyphasic taxonomic approach including analysis of phenotypic, physiological and genotypic characteristics, 16S rRNA gene sequence and DNA-DNA hybridization analysis was used to determine the most consistent affiliation of Pseudomonas pictorum. Pseudomonas pictorum ATCC 23328 T exhibited phenotypic traits of members of the genus Stenotrophomonas including cellular fatty acid composition, quinone and limited range of substrates that could be used. Antibiotic susceptibility and physiological characteristics were determined. The DNA G+C content was 65.7 mol%. Phylogenetic analysis revealed that the type strains of Stenotrophomonas terrae, Stenotrophomonas humi, Stenotrophomonas nitritireducens and Stenotrophomonas acidaminiphila were the nearest relatives (16S rRNA gene sequence similarity of 98.0 to 98.8 %). All the other type strains of species of the genus Stenotrophomonas showed high 16S rRNA gene sequence similarities (96.8 to 97.2 %). DNA-DNA hybridizations revealed 31.0, 32.0, 43.3 and 43.6 %
A Gram-positive, spore-forming, aerobic, rod-shaped, xylanolytic bacterium designated strain CC-Alfalfa-35T was isolated from the rhizosphere of Medicago sativa L. in Taiwan. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain CC-Alfalfa-35T was affiliated to the genus Cohnella. Strain CC-Alfalfa-35T shared 95.3 % pairwise 16S rRNA gene sequence similarity to the type strain of the type species of the genus Cohnella (Cohnella thermotolerans DSM 17683T) besides showing a similarity of 97.4-93.6 % with other recognized species of the genus Cohnella. The DNA-DNA hybridization value between CC-Alfalfa-35T and Cohnella thailandensis KCTC 22296T was 37.7 %±1.7 % (reciprocal value, 55.7 %±3.0 %). Predominant cellular fatty acids were iso-C16 : 0 and anteiso-C15 : 0. The polar lipid profile constituted diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, lysyl-phosphatidylglycerol, three unidentified phospholipids and three unidentified aminophospholipids. The ...
Abstract: A group-specific PCR-based denaturing gradient gel electrophoresis (DGGE) method was developed and combined with group-specific clone library analysis to investigate the diversity of the Clostridium leptum subgroup in human feces. PCR products (length, 239 bp) were amplified using C. leptum cluster-specific primers and were well separated by DGGE. The DGGE patterns of fecal amplicons from 11 human individuals revealed host-specific profiles; the patterns for fecal samples collected from a child for 3 years demonstrated the structural succession of the population in the first 2 years and its stability in the third year. A clone library was constructed with 100 clones consisting of 1,143-bp inserts of 16S rRNA gene fragments that were amplified from one adult fecal DNA with one forward universal bacterial primer and one reverse group-specific primer. Eighty-six of the clones produced the 239-bp C. leptum cluster-specific amplicons, and the remaining 14 clones did not produce these ...
Background Assessment of the biodiversity of communities of small organisms is most readily done using PCR-based analysis of environmental samples consisting of mixtures of individuals. Known as metagenetics, this approach has transformed understanding of microbial communities and is beginning to be applied to metazoans as well. Unlike microbial studies, where analysis of the 16S ribosomal DNA sequence is standard, the best gene for metazoan metagenetics is less clear. In this study we designed a set of PCR primers for the mitochondrial 12S ribosomal DNA sequence based on 64 complete mitochondrial genomes and then tested their efficacy. Methodology/Principal Findings A total of the 64 complete mitochondrial genome sequences representing all metazoan classes available in GenBank were downloaded using the NCBI Taxonomy Browser. Alignment of sequences was performed for the excised mitochondrial 12S ribosomal DNA sequences, and conserved regions were identified for all 64 mitochondrial genomes. These
The 2,030 isolates analyzed in the present study comprised 1,235 isolates from stool samples from hospital patients, 395 isolates from stool samples referred via community practitioners, 150 isolates from the hospital environment, 27 isolates from veterinary sources, 89 isolates from the general environment, 1 isolate from an extraintestinal human site, and 133 reference strains held in the National Collection of Type Cultures, the American Type Culture Collection and the Culture Collection, University of Göteborg, and in the personal collections of C. difficile types held by Delmee and others (6, 16) and other members of the International Study Group on C. difficile (3).. PCR ribotyping was performed in duplicate, with slight modifications to a method described previously (13). Briefly, bacteria were harvested from overnight anaerobic cultures on Fastidious Anaerobe Agar (LabM, Bury, United Kingdom) supplemented with 6% horse blood. Crude template nucleic acid was prepared by resuspension of ...
Résumé: Transfer of Pseudomonas pictorum Gray and Thornton 1928 to genus Stenotrophomonas as Stenotrophomonas pictorum comb. nov., and emended description of the genus Stenotrophomonas Abstract A polyphasic taxonomic approach including analysis of phenotypic, physiological and genotypic characteristics, 16S rRNA gene sequence and DNA-DNA hybridization analysis was used to determine the most consistent affiliation of Pseudomonas pictorum. Pseudomonas pictorum ATCC 23328 T exhibited phenotypic traits of members of the genus Stenotrophomonas including cellular fatty acid composition, quinone and limited range of substrates that could be used. Antibiotic susceptibility and physiological characteristics were determined. The DNA G+C content was 65.7 mol%. Phylogenetic analysis revealed that the type strains of Stenotrophomonas terrae, Stenotrophomonas humi, Stenotrophomonas nitritireducens and Stenotrophomonas acidaminiphila were the nearest relatives (16S rRNA gene sequence similarity of 98.0 to ...
Abstract Environmental enteric dysfunction (EED) is often measured with a dual sugar absorption test and implicated as a causative factor in childhood stunting. Disturbances in the gut microbiota are hypothesized to be a mechanism by which EED is exacerbated, although this supposition lacks support. We performed 16S ribosomal RNA gene sequencing of fecal samples from 81 rural Malawian children with varying degrees of EED to determine which bacterial taxa were associated with EED. At the phyla level, Proteobacteria abundance is reduced with severe EED. Among bacterial genera, Megasphaera, Mitsuokella, and Sutterella were higher in EED and Succinivibrio, Klebsiella, and Clostridium_XI were lower in EED. Bacterial diversity did not vary with the extent of EED. Though EED is a condition that is typically believed to affect the proximal small bowel, and our focus was on stool, our data do suggest that there are intraluminal microbial differences that reflect, or plausibly lead to, EED.
During a study of bacterial diversity of soil, a novel strain, CA-15 , was isolated from Kyonggi University forest soil. Cells were aerobic, Gram-stain-negative, motile, non-spore-forming, rod-shaped, oxidase-positive and catalase- negative. Tyrosine was not oxidized but produced red pigmentation on an agar palte. Strain CA-15 hydrolysed Tween 60 and DNA. It grew at 15-35 C (optimum, 25-30 C), pH 6.0-10.0 (optimum, 7.0-9.0) and at 1.5 % (w/v) NaCl concentration. Phylogenetic analysis based on its 16S rRNA gene sequence indicated that strain CA-15 formed a lineage within the family Caulobacteraceae of the class Alphaproteobacteria that was distinct from various species of the genus Brevundimonas. Brevundimonas bullata DSM 7126 was the closest member of strain CA-15 on the basis of 16S rRNA gene sequence similarity (98.48 %). Q-10 was only an isoprenoid quinone detected for strain CA-15 . The major polar lipids were 1,2-di-O-acyl-3-O-[d-glucopyranosyl-(1→4)-αd-glucopyranuronosyl]glycerol, ...
A novel halophilic actinomycete, strain H32T,was isolated froma Saharan soil sample collected in El-Oued province, south Algeria. The isolate was characterized by means of polyphasic taxonomy. Optimal growth was determined to occur at 28-32°C, pH 6.0-7.0 and in the presence of 15-25 %(w/v) NaCl. The strain was observed to produce abundant aerial mycelium, which formed long chains of rod-shaped spores at maturity, and fragmented substrate mycelium. The cell wall was determined to contain meso-diaminopimelic acid and the characteristic whole-cell sugars were arabinose and galactose. The predominant menaquinoneswere found to beMK-10(H4) andMK-9(H4). The predominant cellular fatty acids were determined to be anteiso C17:0, iso-C15:0 and iso-C16:0. The diagnostic phospholipid detected was phosphatidylcholine. Phylogenetic analyses based on the 16S rRNA gene sequence showed that this strain formed a distinct phyletic line within the radiation of the genus Actinopolyspora. The 16S rRNAgene sequence ...
Haemophilus segnis is a bacterium. H. segnis can be cultured on chocolate agar. Kilian, M. (1976). A Taxonomic Study of the Genus Haemophilus, with the Proposal of a New Species. Journal of General Microbiology. 93 (1): 9-62. doi:10.1099/00221287-93-1-9. ISSN 0022-1287. Kar-Pui Lau, Susanna; Chiu-Yat Woo, Patrick; Yin-Leung Chan, Benedict; Mei-Yuk Fung, Ami; Que, Tak-Lun; Yuen, Kwok-Yung (August 2002). Haemophilus Segnis Polymicrobial and Monomicrobial Bacteraemia Identified by 16S Ribosomal RNA Gene Sequencing. Journal of Medical Microbiology. 51 (8): 635-640. doi:10.1099/0022-1317-51-8-635. Retrieved 28 October 2014 ...
Chronic wounds affect millions of people and cost billions of dollars in the United States each year. These wounds harbor polymicrobial biofilm communities, which can be difficult to elucidate using culturing methods. Clinical molecular microbiological methods are increasingly being employed to investigate the microbiota of chronic infections, including wounds, as part of standard patient care. However, molecular testing is more sensitive than culturing, which results in markedly different results being reported to clinicians. This study compares the results of aerobic culturing and molecular testing (culture-free 16S ribosomal DNA sequencing), and it examines the relative abundance score that is generated by the molecular test and the usefulness of the relative abundance score in predicting the likelihood that the same organism would be detected by culture. Parallel samples from 51 chronic wounds were studied using aerobic culturing and 16S DNA sequencing for the identification of bacteria. One hundred
Four novel strains of saprophytic bacteria were isolated from the soil samples collected in the moist subtropics region (the Black Sea coast of the Caucasus) and studied using methods of polyphasic taxonomic analysis. Microorganisms were Gram-negative, oxidase positive, aerobic, rod-shaped motile bacteria that produced antibiotic named batumin with high and selective activity against staphylococci; its total formula was С 30Н48N2O7. Phylogenetic analysis of 16S rRNA gene sequences (1376 bp, accession number in Genbank - JF306642) indicated that the isolates belonged to the γ-Proteobacteria, formed a separate branch within the genus Pseudomonas and had 98% 16S rRNA gene sequence similarity with Pseudomonas gingeri. The latter essentially differed from the studied strains in its phenotypic characteristics ...
Experimental designs that take advantage of high-throughput sequencing to generate datasets include RNA sequencing (RNA-seq), chromatin immunoprecipitation sequencing (ChIP-seq), sequencing of 16S rRNA gene fragments, metagenomic analysis and selective growth experiments. In each case the underlying data are similar and are composed of counts of sequencing reads mapped to a large number of features in each sample. Despite this underlying similarity, the data analysis methods used for these experimental designs are all different, and do not translate across experiments. Alternative methods have been developed in the physical and geological sciences that treat similar data as compositions. Compositional data analysis methods transform the data to relative abundances with the result that the analyses are more robust and reproducible. Data from an in vitro selective growth experiment, an RNA-seq experiment and the Human Microbiome Project 16S rRNA gene abundance dataset were examined by ALDEx2, a
Two halophilic archaea, designated strains WSM-64(T) and WSM-66, were isolated from a sample taken from a borehole in the currently unexploited Barycz mining area belonging to the Wieliczka Salt Mine Company, in Poland. Strains are red pigmented and form non-motile cocci that stain Gram-negative. Strains WSM-64(T) and WSM-66 showed optimum growth at 40 °C, in 20% NaCl and at pH 6.5-7.5. The strains were facultative anaerobes. The major polar lipids of the two strains were phosphatidylglycerol (PG2), phosphatidylglycerol phosphate methyl ester (PGP-Me) and sulfated diglycosyl diether (S-DGD). Menaquinone MK-8 was the major respiratory quinone. The DNA G+C content of strain WSM-64(T) was 61.2 mol% by HPLC method; 61.0 mol% by genome sequencing. Analysis of the almost complete 16S rRNA gene sequence indicated that the strains WSM-64(T) and WSM-66 (99.7% identity) represented a member of the genus Halorhabdus in the family Halobacteriaceae. Both strains formed a distinct cluster and were most ...
Massively parallel high throughput sequencing technologies allow us to interrogate the microbial composition of biological samples at unprecedented resolution. The typical approach is to perform high-throughout sequencing of 16S rRNA genes, which are then taxonomically classified based on similarity to known sequences in existing databases. Current technologies cause a predicament though, because although they enable deep coverage of samples, they are limited in the length of sequence they can produce. As a result, high-throughout studies of microbial communities often do not sequence the entire 16S rRNA gene. The challenge is to obtain reliable representation of bacterial communities through taxonomic classification of short 16S rRNA gene sequences. In this study we explored properties of different study designs and developed specific recommendations for effective use of short-read sequencing technologies for the purpose of interrogating bacterial communities, with a focus on classification using
Members of phylum Acanthocephala are parasites of vertebrates and arthropods and are distributed worldwide. The phylum has traditionally been divided into three classes, Archiacanthocephala, Palaeacanthocephala, and Eoacanthocephala; a fourth class, Polyacanthocephala, has been recently proposed. However, erection of this new class, based on morphological characters, has been controversial. We sequenced the near complete 18S rRNA gene of Polyacanthorhynchus caballeroi (Polyacanthocephala) and Rhadinorhynchus sp. (Palaeacanthocephala); these sequences were aligned with another 21 sequences of acanthocephalans representing the three widely recognized classes of the phylum and with 16 sequences from outgroup taxa. Phylogenetic relationships inferred by maximum-likelihood and maximum-parsimony analyses showed Archiacanthocephala as the most basal group within the phylum, whereas classes Polyacanthocephala + Eoacanthocephala formed a monophyletic clade, with Palaeacanthocephala as its sister group. ...
A bacterial strain (CCUG 44693T) was recovered during an industrial hygiene control. Phylogenetic analyses using the 16S rRNA gene sequence of the isolate indicated that it represents a new lineage in the α-1 subclass of the Proteobacteria, with the highest sequence similarity of 93.3% to the type strain of Muricoccus roseus. In the polyamine pattern spermidine was the predominant compound. The polar lipid profile consisted of the major lipids phosphatidyl ethanolamine, phosphatidyl dimethylethanolamine, phosphatidyl glycerol, phosphatidyl cholin and an unknown amino lipid. The major respiratory quinone was a ubiquinone Q-10 and the major whole cell fatty acids were 19:0 cyclo ω8c and 18:1 ω7c. The isolate also contained 18:1 2-OH and other fatty acids typical for members of the α-1 subclass of the Proteobacteria in addition to 10:0 2-OH in low amounts, not detected in members of closely related genera. The strain grew heterotrophically and strictly aerobically and formed red-colored ...
A Gram-negative, heterotrophic, marine bacterium, designated strain SW-11(T), was isolated from the reef-building coral Isopora palifera in Kenting, Taiwan. Cells were rods and were motile by a single polar flagellum. The strain grew at 10-45 degrees C (optimum, 30-35 degrees C), at pH 7.0-8.0 (optimum, pH 7.5) and with 2.0-4.0% NaCl (optimum, 2.5-3.0%). The polar lipids comprised phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and four unknown phospholipids. Isoprenoid quinones consisted of ubiquinone 9 (78.8%) and ubiquinone 8(21.1%). Major cellular fatty acids were summed feature 3 (C(16:1)omega 7c and/or C(16:1)omega 6c; 22.3%), C(17:1)omega 8c (13.4%), summed feature 8 (C(18:1)omega 6c and/or C(18:1)omega 7c; 13.1%), C(16:0) (10.3%) and anteiso-C(17:1)omega 9c (10.0%). The DNA G+C content was 51.6 mol%. 165 rRNA gene sequence analysis indicated that strain SW-11(T) belongs to the class Gammaproteobacteria and is a member of the order ...
The 16S rRNA gene sequence analysis of Bifidobacterium species reveals high interspecies sequence similarity in the range of 87.7-99.5%. This study illustrated the extent of superiority of a multigenic approach, involving protein-coding genes, in comparison to the 16S rRNA gene, to precisely delineate presumptive Bifidobacterium isolates obtained from probiotic milk beverages, culture collections and pharmaceutical probiotic preparations. Oligonucleotide pairs PurF-rev/PurF-uni; RpoCuni/ RpoC-rev; DnaB-uni/DnaB-rev; DnaG-uni/DnaG-rev; and ClpC-uni/ClpC-rev amplified housekeeping genes while 27F/ 1492R amplified the 16S rRNA gene of the presumptive bifidobacteria in a polymerase chain reaction. Sequences of 16S rRNA gene and some protein-coding genes effectively identified the isolates. Phylogenetic analysis together with concatenation showed that clpC, purF and dnaG genes had over 8-fold better discriminatory power than the 16S rRNA gene in discriminating between Bifidobacterium isolates. ...
The structure of microbial communities was examined as a function of community composition and the relative abundance of specific microbial groups to examine the effects that plant community composition and land-use history have on microbial communities in the soil. The sites sampled were part of the Long Term Ecological Research (LTER) project in agricultural ecology at the W.K. Kellogg Biological Station of Michigan State University (Hickory Corners, MI) and included both active and abandoned agricultural fields as well as nearby fields that had never been cultivated. Microbial community structure was assessed by extracting total RNA from soil samples and using 16S rRNA-targeted oligonucleotide probes to quantify the abundance of rRNA from the alpha, beta, and gamma Proteobacteria, the Actinobacteria (Gram positive bacteria with a high mol % G+C genome), the Bacteria, and the Eukarya. In addition, soil microbial communities were characterized by examining fluorescently tagged terminal ...
Chen, H.,Lim, C.K.,Lee, Y.K.,Chan, Y.N. (2000). Comparative analysis of the genes encoding 23S-5S rRNA intergenic spacer regions of Lactobacillus casei-related strains. International Journal of Systematic and Evolutionary Microbiology 50 (2) : 471-478. [email protected] Repository ...
A novel Gram-negative, slightly halophilic, catalase-positive, oxidase-negative, obligately aerobic, non-sporulating rod-shaped bacterium, designated strain JSM 078169(T), was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. Growth occurred with 1-20 % (w/v) total salts (optimum, 3-5 %), at pH 6.0-10.5 (optimum, pH 7.5) and at 4-40 degrees C (optimum, 25-30 degrees C). The major cellular fatty acids were C-18: 1 omega 7c, C-16:0 and C-12:0 3-OH. The predominant respiratory quinone was Q-9 and the genomic DNA G + C content was 55.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 078169(T) should be assigned to the genus Halomonas. The sequence similarities between the isolate and the type strains of members of the genus Halomonas were in the range 92.4-97.0%. The combination of phylogenetic analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain JSM 078169(T) ...
Investigation of the initial and spoilage microbial diversity of iced stored sea bream was carried out. Culture dependent methods were used for bacterial enumeration and phenotypic identification of bacterial isolates, while culture independent methods, using bacterial 16S rRNA gene amplification, cloning and sequencing of DNA extracted directly from the flesh were also employed. The culture dependent approach revealed that the initial microbiota was dominated by Acinetobacter, Shewanella, Pseudomonas and Flavobacterium, while at the end of shelf-life determined by sensory analysis (16 days), the predominant microbiota was Pseudomonas and Shewanella. Culture independent approach showed that initially the sea bream flesh was strongly dominated by Acinetobacter, while Pseudomonas, Aeromonas salmonicida and Shewanella were the predominant phylotypes at the end of shelf-life. Initial and spoilage microbiota comprised of phylotypes previously identified by others using traditional or molecular ...
TY - JOUR. T1 - Diversity of Haloquadratum and other haloarchaea in three, geographically distant, Australian saltern crystallizer ponds. AU - Oh, Dickson. AU - Porter, Kate. AU - Russ, Brendan. AU - Burns, David. AU - Dyall-Smith, Mike. PY - 2010/3. Y1 - 2010/3. N2 - Haloquadratum walsbyi is frequently a dominant member of the microbial communities in hypersaline waters. 16S rRNA gene sequences indicate that divergence within this species is very low but relatively few sites have been examined, particularly in the southern hemisphere. The diversity of Haloquadratum was examined in three coastal, but geographically distant saltern crystallizer ponds in Australia, using both culture-independent and culture-dependent methods. Two 97%-OTU, comprising Haloquadratum- and Halorubrum-related sequences, were shared by all three sites, with the former OTU representing about 40% of the sequences recovered at each site. Sequences 99.5% identical to that of Hqr. walsbyi C23T were present at all three sites ...
PubMed journal article: Use of 16S rRNA gene sequencing for rapid identification and differentiation of Burkholderia pseudomallei and B. mallei. Download Prime PubMed App to iPhone, iPad, or Android
Staphylococcus aureus is an important human and animal pathogen, and is regarded as an important cause of intramammary infection (IMI) in ruminants. Staphylococcus aureus genetic variability and virulence factors have been well studied in veterinary medicine, especially in cows as support for control and management of IMI. The aim of the present study was to genotype 71 Staph. aureus isolates from the bulk tank and foremilk of water buffaloes (n. = 40) and from udder tissue (n. = 7) and foremilk (n. = 24) from small ruminants. The method used was previously applied to bovine Staph. aureus and is based on the amplification of the 16S-23S rRNA intergenic spacer region. The technique applied was able to identify different Staph. aureus genotypes isolated from dairy species other than the bovine species, and cluster the genotypes according to species and herds. Virulence gene distribution was consistent with genotype differentiation. The isolates were also characterized through determination of the ...
The bacterial communities of aphids were investigated by terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis analysis of 16S rRNA gene fragments generated by PCR with general eubacterial primers. By both methods, the -proteobacterium Buchnera was detected in laboratory cultures of six parthenogenetic lines of the pea aphid Acyrthosiphon pisum and one line of the black bean aphid Aphis fabae, and one or more of four previously described bacterial taxa were also detected in all aphid lines except one of A. pisum. These latter bacteria, collectively known as secondary symbionts or accessory bacteria, comprised three taxa of -proteobacteria (R-type [PASS], T-type [PABS], and U-type [PAUS]) and a rickettsia (S-type [PAR]). Complementary analysis of aphids from natural populations of four aphid species (A. pisum [n 74], Amphorophora rubi [n 109], Aphis sarothamni [n 42], and Microlophium carnosum [n 101]) from a single geographical location revealed Buchnera ...
Looking for online definition of DNA-DNA hybridization in the Medical Dictionary? DNA-DNA hybridization explanation free. What is DNA-DNA hybridization? Meaning of DNA-DNA hybridization medical term. What does DNA-DNA hybridization mean?
Evaluating the composition of the human gut microbiota greatly facilitates studies on its role in human pathophysiology, and is heavily reliant on culture-independent molecular methods. A microarray designated the Human Gut Chip (HuGChip) was developed to analyze and compare human gut microbiota samples. The PhylArray software was used to design specific and sensitive probes. The DNA chip was composed of 4,441 probes (2,442 specific and 1,919 explorative probes) targeting 66 bacterial families. A mock community composed of 16S rRNA gene sequences from intestinal species was used to define the threshold criteria to be used to analyze complex samples. This was then experimentally verified with three human faecal samples and results were compared (i) with pyrosequencing of the V4 hypervariable region of the 16S rRNA gene, (ii) metagenomic data, and (iii) qPCR analysis of three phyla. When compared at both the phylum and the family level, high Pearsons correlation coefficients were obtained between ...
The Hallman et al. [8] definition of endophytic bacteria requires surface-disinfested plant tissue or extraction from the plant. Disinfestation by killing all the epiphytic bacteria may be effective when culture-dependent protocols are used, but is not appropriate in culture-independent protocols, such as the present one, since the DNA or RNA of dead epiphytes, if not removed, would still be amplified by bacteria-specific PCR. For those organs, like tubers, whose outer layers can be easily peeled off, endophytic bacteria can be isolated from inside of the plants unambiguously. However, peeling the epidermis off leaves, while possible, is not practical for a study like the present one. Therefore, to study leaf endophytic bacterial communities, it is critical to dislodge epiphytic bacteria from the leaf surfaces as far as possible. We have dislodged epiphytes using methods similar to those reported by others [13, 26-28]. Since we did not test the rinse water for rDNA amplicons, we cannot be ...
Oceanospirillales merupakan ordo yang beraneka ragam jika dilihat dari sisi morfologi dan metabolismenya. Beberapa dapat tumbuh di tengah-tengah oksigen, sementara yang lain membutuhkan lingkungan yang anaerob.[2] Most Oceanospirillales are prefer or require high salt concentrations to grow.[2] Mereka ada di berbagai macam relung, tetapi Oceanospirillales memperoleh energi dengan mengolah berbagai produk organik. Semua bakteri Oceanospirillales bersifat motil kecuali untuk anggota genus Alcanivorax.[2] ...
The aim of this work was to determine the effect of light crude oil on bacterial communities during an experimental oil spill in the North Sea and in mesocosms (simulating a heavy, enclosed oil spill), and to isolate and characterize hydrocarbon-degrading bacteria from the water column. No oil-induced changes in bacterial community (3 m below the sea surface) were observed 32 h after the experimental spill at sea. In contrast, there was a decrease in the dominant SAR11 phylotype and an increase in Pseudoalteromonas spp. in the oiled mesocosms (investigated by 16S rRNA gene analysis using denaturing gradient gel electrophoresis), as a consequence of the longer incubation, closer proximity of the samples to oil, and the lack of replenishment with seawater. A total of 216 strains were isolated from hydrocarbon enrichment cultures, predominantly belonging to the genus Pseudoaltero monas; most strains grew on PAHs, branched and straight-chain alkanes, as well as many other carbon sources. No obligate ...
Automated Ribosomal Intergenic Spacer Analysis (ARISA) - Science Exchange Lets You Compare Quotes From Leading Service Providers.
16S rRNA sequencing data on human skin microbiome samples collected before and after swimming in the ocean. This dataset contains raw sequencing data contained in fasta and qual files produced from an Ion Torrent PGM sequencer. There were 2 sampling occurrences (041218 and 092718) and each occurrence has an associated fasta and qual file. This dataset contains the 092718 sampling data only due to storage restrictions. The other dataset is published separately. Our research has shown that the human skin microbiome is altered after swimming in the ocean. Normal commensals were washed off and simultaneously, exogenous bacteria were deposited on the skin. QIIME was used for initial analysis and indicated that the abundance and diversity of microbial communities on the skin increased after swimming and these changes persisted for more than 24 hours. Downstream analysis using PICRUSt to predict functional metagenomics indicated that there was an increase in antibiotic resistance genes, antibiotic biosynthesis
As the importance of beneficial bacteria is better recognized, understanding the dynamics of symbioses becomes increasingly crucial. In many gut symbioses, it is essential to understand whether changes in host diet play a role in the persistence of the bacterial gut community. In this study, termites were fed six dietary sources and the microbial community was monitored over a 49-day period using 16S rRNA gene sequencing. A deep backpropagation artificial neural network (ANN) was used to learn how the six different lignocellulose food sources affected the temporal composition of the hindgut microbiota of the termite as well as taxon-taxon and taxon-substrate interactions. Shifts in the termite gut microbiota after diet change in each colony were observed using 16S rRNA gene sequencing and beta diversity analyses. The artificial neural network accurately predicted the relative abundances of taxa at random points in the temporal study and showed that low-abundant taxa maintain community driving
Microbial biodiversity is difficult to measure in extreme environments due to the inability to culture many of the species, especially from hypersaline environments. Great Salt Lake (GSL), Utah, USA offers a unique ecology to study microbial diversity across a salt gradient. GSL has increasing salt from South to North that varies from marine salt concentrations to saturation, respectively. We used three methods to examine the biodiversity of the GSL-traditional cultivation on solid media, 16s rRNA gene sequencing, multiplexed 16s rRNA gene hybridization to the phylochip, and DNA hybridization to the Geochip for metabolic diversity estimates. Over 40 isolates from the North Arm were obtained, while six were selected for identification. Isolates included gammaproteobacteria, bacilli, and actinobacteria. Sequencing the 16S rRNA genes for identification yielded 350 clones. Refraction curves indicated that this did not represent the bacterial diversity of the GSL, while estimation of the diversity with the
Two bacterial species were isolated from a salt marsh located on privately owned land in Russell County, Kansas. Water samples from the saIt marsh were streaked for isolation on tryptic soy agar supplemented with 12 % NaCI. Visual scanning of the plates revealed two prominent colony types. The two colony types were subcultured repeatedly until axenic cultures were obtained. 80th of these organisms were shown to be moderately halophilic. The organisms were characterized partially by fatty acid methyl ester analysis, 16S rRNA sequencing, and scanning electron microscopy. These studies revealed that the bacteria previously were unreported members of genera Marinococcus and Halomonas.
Black Band Disease (BBD), the destructive microbial consortium dominated by the cyanobacterium Roseofilum reptotaenium, affects corals worldwide. While the taxonomic composition of BBD consortia has been well-characterized, substantially less is known about its functional repertoire. We sequenced the metagenomes of Caribbean and Pacific black band mats and cultured Roseofilum and obtained five metagenome-assembled genomes (MAGs) of Roseofilum, nine of Proteobacteria, and 12 of Bacteroidetes. Genomic content analysis suggests that Roseofilum is a source of organic carbon and nitrogen, as well as natural products that may influence interactions between microbes. Proteobacteria and Bacteroidetes members of the disease consortium are suited to the degradation of amino acids, proteins, and carbohydrates. The accumulation of sulfide underneath the black band mat, in part due to a lack of sulfur oxidizers, contributes to the lethality of the disease. The presence of sulfide:quinone oxidoreductase genes in all
In the present study, we investigated the bacterial diversity of aMasi, a traditional South African fermented milk product, by 16S rRNA clone library and Denaturing Gradient Gel Electrophoresis (DGGE) analysis. Two hundred and eighty two clones from clone library were isolated and identified from aMasi, prepared from the milk of four cows from one herd in the EkuPindiseni Community, North West of Hluhluwe-iMfolozi Park in KwaZulu-Natal Province. The majority of the identified sequences corresponded to lactic acid bacteria (LAB), with the genus Lactococcus as major representative. The species Lactococcus lactis accounted for 179 of the identified clones. In addition, several species of Lactobacillus, Leuconostoc and Enterococcus were detected. Furthermore, several clones belonging to Acinetobacter, Aeromonas and genera within the Enterobacteriaceae were detected. It is important to note that human pathogens such as Klebsiella pneumoniae were identified in aMasi in the present study. Conversely, ...
The screening of bacteria isolated from soil, water and sediment samples of the Gavkhooni Wetland in Iran led to the isolation of about 161 moderately halophilic and halotolerant bacteria which were able to accumulate intracellular lipid inclusions under conditions of nitrogen limitation. Primary studies showed that most of the isolates were able to produce these inclusions but that only a Gram-negative, rod-shaped halotolerant bacterium, designated as strain GK1(IBRC-M10197), showed high-capacity production in a wide range of culture conditions. Gas chromatography and Fourier transform infrared spectroscopy studies revealed that the inclusions were poly-β-hydroxybutyrate (PHB). Phenotypic characterization and phylogenetic analysis based on 16S rRNA gene sequence comparison showed that this strain is a member of the genus Oceanimonas. The genome sequence study of this bacterium revealed the presence of genes involved in the PHB synthesis pathway, which was supported by results of the ...
Three strictly anaerobic, Gram-positive, non-spore-forming, rod-shaped, motile bacteria, designated strains ACB1(T), ACB7(T) and ACB8, were isolated from human subgingival dental plaque. All strains required yeast extract for growth. Strains ACB1(T) and ACB8 were able to grow on glucose, lactose, maltose, maltodextrin and raffinose; strain ACB7(T) grew weakly on sucrose only. The growth temperature range was 30-42 °C with optimum growth at 37 °C. Major metabolic fermentation end products of strain ACB1(T) were acetate and lactate; the only product of strains ACB7(T) and ACB8 was acetate. Major fatty acids of strain ACB1(T) were C(14 : 0), C(16 : 0), C(16 : 1)ω7c dimethyl aldehyde (DMA) and C(18 : 1)ω7c DMA. Major fatty acids of strain ACB7(T) were C(12 : 0), C(14 : 0), C(16 : 0), C(16 : 1)ω7c and C(16 : 1)ω7c DMA. The hydrolysate of the peptidoglycan contained meso-diaminopimelic acid, indicating peptidoglycan type A1γ. Genomic DNA G+C content varied from 42 to 43.3% between strains. ...
Symbiotic relationships with subcuticular bacteria (SCB) have been identified and studied in numerous echinoderms, but have not been examined using current sequencing technologies in the brooding brittle star, Amphipholis squamata. Previously, A. squamata SCB were placed in the genus Vibrio (γ-Proteobacteria), but recent evidence suggests the SCB is primarily composed of α-Proteobacteria. The present study clarifies the taxonomic composition of SCB associated with A. squamata from the Northwest Atlantic. Isolated gDNA was amplified using 16S rRNA gene-targeted PCR and sequenced on an Illumina HiSeq at the UNH Genomics Center. Results suggest the presence of a single dominant bacterial type within the family Rhodobacteraceae, which composes 70-80% of the A. squamata microbiome. The majority of sequences within Rhodobacteraceae were identified as members of the genus Octadecabacter (97% similarity). By comparison, adjacent seawater and sediment support significantly more diverse bacterial communities,
TY - JOUR. T1 - Some Observations on the Taxonomy of the Genus Microbacterium. II. Cell Wall Analysis, Gel Electrophoresis and Serology. AU - Robinson, K.. PY - 1966/12. Y1 - 1966/12. N2 - Summary. The chemical composition of the cell wall mucopeptide, the esterases and catalases of the cell free extracts, and the serology of the 25 species of microbacteria whose morphological and cultural characteristics had been investigated previously, were examined. Suggestions are made about the relationships of the species within the genus Microbacterium and with other genera.. AB - Summary. The chemical composition of the cell wall mucopeptide, the esterases and catalases of the cell free extracts, and the serology of the 25 species of microbacteria whose morphological and cultural characteristics had been investigated previously, were examined. Suggestions are made about the relationships of the species within the genus Microbacterium and with other genera.. UR - ...
Volatile fatty acid intoxication (acidosis), a common process failure recorded in anaerobic reactors, leads to drastic losses in methane production. Unfortunately, little is known about the microbial mechanisms underlining acidosis and the potential to recover the process. In this study, triplicate mesophilic anaerobic reactors of 100 L were exposed to acidosis resulting from an excessive feeding with sugar beet pulp and were compared to a steady-state reactor. Stable operational conditions at the beginning of the experiment initially led to similar microbial populations in the four reactors, as revealed by 16S rRNA gene T-RFLP and high-throughput amplicon sequencing. Bacteroidetes and Firmicutes were the two dominant phyla, and although they were represented by a high number of operational taxonomic units, only a few were dominant. Once the environment became deterministic (selective pressure from an increased substrate feeding), microbial populations started to diverge between the overfed reactors.
The marine bacterium Halomonas titanicae strain BH1 was isolated from a sample of rusticles, which are formed in part by a consortium of microorganisms, collected from the RMS Titanic wreck site (1). This bacterium was previously characterized as a new species of the genus Halomonas, which includes a large number of species isolated predominantly from marine, hypersaline, or alkaline habitats (saline lakes, salterns, salted food, etc.). Although these species are easily isolated from saline and hypersaline environments, genome data are currently available only from the type species of the genus Halomonas, H. elongata (2). Halomonas titanicae is a Gram-negative, heterotrophic, aerobic rod, motile by peritrichous flagella. Phylogenetically this organism belongs to the Gammaproteobacteria within the family Halomonadaceae (3, 4). This halophilic organism has a respiratory metabolism, being able to grow in media with 0.5 to 25% NaCl (optimal growth at 2 to 8% NaCl); no growth occurs in the absence of ...