Symbionts of the gut flagellate Staurojoenina sp. from Neotermes cubanus represent a novel, termite-associated lineage of Bacteroidales: description of ‘Candidatus Vestibaculum illigatum’

Microbiology ◽  
2004 ◽  
Vol 150 (7) ◽  
pp. 2229-2235 ◽  
Author(s):  
Ulrich Stingl ◽  
Annelie Maass ◽  
Renate Radek ◽  
Andreas Brune
Keyword(s):  
Electron Microscopy ◽  
Cell Envelope ◽  
Pcr Amplification ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phylogenetic Position ◽  
New Taxon ◽  
Uniform Size ◽  
Special Attachment ◽  
Size And Morphology

The symbioses between cellulose-degrading flagellates and bacteria are one of the most fascinating phenomena in the complex micro-ecosystem found in the hindgut of lower termites. However, little is known about the identity of the symbionts. One example is the epibiotic bacteria colonizing the surface of hypermastigote protists of the genus Staurojoenina. By using scanning electron microscopy, it was shown that the whole surface of Staurojoenina sp. from the termite Neotermes cubanus is densely covered with long rod-shaped bacteria of uniform size and morphology. PCR amplification of 16S rRNA genes from isolated protozoa and subsequent cloning yielded a uniform collection of clones with virtually identical sequences. Phylogenetic analysis placed them as a new lineage among the Bacteroidales, only distantly related to other uncultivated bacteria in the hindgut of other termites, including an epibiont of the flagellate Mixotricha paradoxa. The closest cultivated relative was Tannerella forsythensis (<85 % sequence identity). Fluorescence in situ hybridization with a newly designed clone-specific oligonucleotide probe confirmed that these sequences belong to the rod-shaped epibionts of Staurojoenina sp. Transmission electron microscopy confirmed the presence of a Gram-negative cell wall and revealed special attachment sites for the symbionts on the cell envelope of the flagellate host. Based on the isolated phylogenetic position and the specific association with the surface of Staurojoenina sp., we propose to classify this new taxon of Bacteroidales under the provisional name ‘Candidatus Vestibaculum illigatum’.

scholarly journals “Candidatus Hepatoplasma crinochetorum,” a New, Stalk-Forming Lineage of Mollicutes Colonizing the Midgut Glands of a Terrestrial Isopod

2004 ◽  
Vol 70 (10) ◽  
pp. 6166-6172 ◽  
Author(s):  
Yongjie Wang ◽  
Ulrich Stingl ◽  
Friederike Anton-Erxleben ◽  
Sabine Geisler ◽  
Andreas Brune ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
New Taxon ◽  
Epithelial Surface ◽  
Porcellio Scaber ◽  
Homogeneous Population ◽  
Terrestrial Isopod

ABSTRACT Uncultivated bacteria that densely colonize the midgut glands (hepatopancreas) of the terrestrial isopod Porcellio scaber (Crustacea: Isopoda) were identified by cloning and sequencing of their 16S rRNA genes. Phylogenetic analysis revealed that these symbionts represent a novel lineage of the Mollicutes and are only distantly related (<82% sequence identity) to members of the Mycoplasmatales and Entomoplasmatales. Fluorescence in situ hybridization with a specific oligonucleotide probe confirmed that the amplified 16S rRNA gene sequences indeed originated from a homogeneous population of symbionts intimately associated with the epithelial surface of the hepatopancreas. The same probe also detected morphotypically identical symbionts in other crinochete isopods. Scanning and transmission electron microscopy revealed uniform spherical bacterial cells without a cell wall, sometimes interacting with the microvilli of the brush border by means of stalk-like cytoplasmic appendages, which also appeared to be involved in cell division through budding. Based on the isolated phylogenetic position and unique cytological properties, the provisional name “Candidatus Hepatoplasma crinochetorum” is proposed for this new taxon of Mollicutes colonizing the hepatopancreas of P. scaber.

Blomineral Compartmentalization in Uncultured Magnetic Bacteria

2001 ◽  
Vol 7 (S2) ◽  
pp. 758-759
Author(s):  
Ulysses Lins ◽  
Carolina N. Keim ◽  
Marcos Farina
Keyword(s):  
Electron Microscopy ◽  
Element Distribution ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phylogenetic Position ◽  
Energy Filtering ◽  
Cell Compartments ◽  
Transmission Electron ◽  
Membrane Bound ◽  
Field Lines

Magnetic bacteria are a group of motile microorganisms that orient to magnetic field lines because of membrane-bound organelles called magnetosomes. Magnetic bacteria precipitate magnetite (Fe3O4) or greigite (Fe3S4) in their magnetosomes. The ability of uncultured magnetic bacteria of accumulating minerals in different cell compartments is still poorly understood. We have been studying natural enrichments of magnetic bacteria from the Itaipu and Rodrigo de Freitas lagoons, in Rio de Janeiro, Brazil. Here, we have used energy-filtering transmission electron microscopy to study the element distribution in biocomposites found in magnetic bacteria from both lagoons. in Itaipu lagoon, electron microscopy and phylogenetic position determination by 16S rRNA genes sequencing identified at least four morphotypes of magnetic bacteria. Typical structures found in all gram-negative bacteria, in addition to some internal compartments were observed (Fig. la). Amorphous granules (Fig. la) and magnetosomes (Fig. lb) were the two well-defined compartments that accumulated significant amounts of minerals.

scholarly journals Evaluation of 16S, map1 and pCS20 probes for detection of Cowdria and Ehrlichia species

1999 ◽  
Vol 122 (2) ◽  
pp. 323-328 ◽  
Author(s):  
M. T. E. P. ALLSOPP ◽  
C. M. HATTINGH ◽  
S. W. VOGEL ◽  
B. A. ALLSOPP
Keyword(s):  
16S Rrna ◽  
Ribosomal Rna ◽  
Pcr Amplification ◽  
16S Ribosomal Rna ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Amblyomma Hebraeum ◽  
Ribosomal Rna Gene ◽  
Group Iii ◽  
16S Ribosomal Rna Gene

A panel of 16S ribosomal RNA gene probes has been developed for the study of the epidemiology of heartwater; five of these detect different cowdria genotypes, one detects five distinct genotypes; one detects any Group III Ehrlichia species other than Cowdria and one detects any Group II Ehrlichia species. These probes have been used on PCR-amplified rickettsial 16S rRNA genes from over 200 Amblyomma hebraeum ticks. Control ticks were laboratory-reared and either uninfected or fed on sheep experimentally infected with different cowdria isolates, field ticks were collected from animals in heartwater-endemic areas. All tick-derived DNA samples were also examined by PCR amplification and probing for two other cowdria genes (map1 and pCS20) which have previously been used for heartwater epidemiology. This paper describes the first direct comparison of all currently available DNA probes for heartwater-associated organisms.

Alkalibacterium gilvum sp. nov., slightly halophilic and alkaliphilic lactic acid bacterium isolated from soft and semi-hard cheeses

2013 ◽  
Vol 63 (Pt_4) ◽  
pp. 1471-1478 ◽  
Author(s):  
Morio Ishikawa ◽  
Kazuhide Yamasato ◽  
Kayo Kodama ◽  
Hinako Yasuda ◽  
Mioko Matsuyama ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Molar Ratio ◽  
Phylogenetic Position ◽  
Growth Responses ◽  
Cultivation Conditions ◽  
Content Type ◽  
Link Type

Nine novel strains of halophilic and alkaliphilic lactic acid bacteria isolated from European soft and semi-hard cheeses by using a saline, alkaline medium (7 % NaCl, pH 9.5) were taxonomically characterized. The isolates were Gram-stain-positive, non-sporulating and non-motile. They lacked catalase and quinones. Under anaerobic cultivation conditions, lactate was produced from d-glucose with the production of formate, acetate and ethanol with a molar ratio of approximately 2 : 1 : 1. Under aerobic cultivation conditions, acetate and lactate were produced from d-glucose. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. The optimum NaCl concentration for growth ranged between 2.0 % and 5.0 % (w/v), with a growth range of 0–1 % to 15–17.5 %. The optimum pH for growth ranged between 8.5 and 9.5, with a growth range of 7.0–7.5 to 9.5–10.0. Comparative sequence analysis of the 16S rRNA genes revealed that the isolates occupied a phylogenetic position within the genus Alkalibacterium , showing the highest sequence similarity (98.2 %) to Alkalibacterium kapii T22-1-2T. The isolates constituted a single genomic species with DNA–DNA hybridization values of 79–100 % among the isolates and <29 % between the isolates and other members of the genus Alkalibacterium , from which the isolates were different in motility and flagellation, growth responses to NaCl concentrations and pH, and profiles of sugar fermentation. The DNA G+C contents were between 36.0 and 37.6 mol%. The cell-wall peptidoglycan was type A4β, Orn-d-Asp. The major components of cellular fatty acids were C14 : 0, C16 : 0 and C16 : 1ω9c. Based on the phenotypic characteristics and genetic distinctness, the isolates are classified as a novel species within the genus Alkalibacterium , for which the name Alkalibacterium gilvum sp. nov. is proposed. The type strain is 3AD-1T ( = DSM 25751T = JCM 18271T).

scholarly journals Reclassification of Trichlorobacter thiogenes as Geobacter thiogenes comb. nov.

2007 ◽  
Vol 57 (3) ◽  
pp. 463-466 ◽  
Author(s):  
Kelly P. Nevin ◽  
Dawn E. Holmes ◽  
Trevor L. Woodard ◽  
Sean F. Covalla ◽  
Derek R. Lovley
Keyword(s):  
Type Strain ◽  
Original Description ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Phylogenetic Position ◽  
Temperature Optimum ◽  
Ph Optimum ◽  
Donor And Acceptor ◽  
The Family ◽  
Electron Donor And Acceptor

Reclassification of the species Trichlorobacter thiogenes as Geobacter thiogenes comb. nov. is proposed on the basis of physiological traits and phylogenetic position. Characteristics additional to those provided in the original description revealed that the type strain (strain K1T=ATCC BAA-34T=JCM 14045T) has the ability to use Fe(III) as an electron acceptor for acetate oxidation and has an electron donor and acceptor profile typical of a Geobacter species, contains abundant c-type cytochromes, and has a temperature optimum of 30 °C and a pH optimum near pH 7.0; traits typical of members of the genus Geobacter. Phylogenetic analysis of nifD, recA, gyrB, rpoB, fusA and 16S rRNA genes further indicated that T. thiogenes falls within the Geobacter cluster of the family Geobacteraceae. Based on extensive phylogenetic evidence and the fact that T. thiogenes has the hallmark physiological characteristics of a Geobacter species, Trichlorobacter thiogenes should be reclassified as a member of the genus Geobacter.

scholarly journals Oligonucleotide Microarray for 16S rRNA Gene-Based Detection of All Recognized Lineages of Sulfate-Reducing Prokaryotes in the Environment

2002 ◽  
Vol 68 (10) ◽  
pp. 5064-5081 ◽  
Author(s):  
Alexander Loy ◽  
Angelika Lehner ◽  
Natuschka Lee ◽  
Justyna Adamczyk ◽  
Harald Meier ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Pcr Amplification ◽  
Oligonucleotide Microarray ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Clinical Samples ◽  
Rrna Gene ◽  
Sulfate Reducing ◽  
Specific Pcr

ABSTRACT For cultivation-independent detection of sulfate-reducing prokaryotes (SRPs) an oligonucleotide microarray consisting of 132 16S rRNA gene-targeted oligonucleotide probes (18-mers) having hierarchical and parallel (identical) specificity for the detection of all known lineages of sulfate-reducing prokaryotes (SRP-PhyloChip) was designed and subsequently evaluated with 41 suitable pure cultures of SRPs. The applicability of SRP-PhyloChip for diversity screening of SRPs in environmental and clinical samples was tested by using samples from periodontal tooth pockets and from the chemocline of a hypersaline cyanobacterial mat from Solar Lake (Sinai, Egypt). Consistent with previous studies, SRP-PhyloChip indicated the occurrence of Desulfomicrobium spp. in the tooth pockets and the presence of Desulfonema- and Desulfomonile-like SRPs (together with other SRPs) in the chemocline of the mat. The SRP-PhyloChip results were confirmed by several DNA microarray-independent techniques, including specific PCR amplification, cloning, and sequencing of SRP 16S rRNA genes and the genes encoding the dissimilatory (bi)sulfite reductase (dsrAB).

Changes in the structure and diversity of bacterial communities during the process of adaptation to organic wastewater

2010 ◽  
Vol 56 (4) ◽  
pp. 352-355 ◽  
Author(s):  
Junmin Li ◽  
Zexin Jin ◽  
Binbin Yu
Keyword(s):  
Bacterial Communities ◽  
Denaturing Gradient Gel Electrophoresis ◽  
Similarity Index ◽  
Pcr Amplification ◽  
Genotypic Diversity ◽  
Diversity Indices ◽  
Inhibitory Effect ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Gradient Gel Electrophoresis

To explore changes in the structure and diversity of activated sludge-derived microbial communities during adaptation to gradual increases in the concentration of wastewater, RAPD–PCR and the combination of PCR amplification of 16S rRNA genes with denaturing gradient gel electrophoresis (DGGE) analysis were used. In bacterial communities exposed to 0%, 5%, 10%, 20%, or 40% wastewater, there were 27, 25, 18, 17 and 16 bands, respectively, based on DGGE data, while there were 69, 83, 97, 86, and 88 bands, respectively, based on RAPD data. The community similarity index among bacterial communities during the process of adaptation to different concentrations of wastewater was different based on DGGE and RAPD data. Based on DGGE and RAPD profiles, the Shannon–Weiner and Simpson’s diversity indices decreased sharply upon exposure to 10% wastewater, indicating that 10% wastewater might be a critical point at which the growth of bacteria could be significantly inhibited and the genotypic diversity could change. This indicated that changes in structure and diversity might have an inhibitory effect on the toxicity of organic matter and that selection and adaptation could play important roles in the changes.

scholarly journals Prey Range Characterization, Ribotyping, and Diversity of Soil and Rhizosphere Bdellovibriospp. Isolated on Phytopathogenic Bacteria

2000 ◽  
Vol 66 (6) ◽  
pp. 2365-2371 ◽  
Author(s):  
E. Jurkevitch ◽  
D. Minz ◽  
Barak Ramati ◽  
Gili Barel
Keyword(s):  
16S Rrna ◽  
Common Bean ◽  
Pcr Amplification ◽  
Erwinia Carotovora ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
Range Analysis ◽  
Pcr Product ◽  
Utilization Patterns ◽  
Range Characterization

ABSTRACT Thirty new Bdellovibrio strains were isolated from an agricultural soil and from the rhizosphere of plants grown in that soil. Using a combined molecular and culture-based approach, we found that the soil bdellovibrios included subpopulations of organisms that differed from rhizosphere bdellovibrios. Thirteen soil and seven common bean rhizosphere Bdellovibrio strains were isolated when Pseudomonas corrugata was used as prey; seven and two soil strains were isolated when Erwinia carotovora subsp.carotovora and Agrobacterium tumefaciens, respectively, were used as prey; and one tomato rhizosphere strain was isolated when A. tumefaciens was used as prey. In soil and in the rhizosphere, depending on the prey cells used, the concentrations of bdellovibrios were between 3 × 102 to 6 × 103 and 2.8 × 102 to 2.3 × 104 PFU g−1. A prey range analysis of five soil and rhizosphereBdellovibrio isolates performed with 22 substrate species, most of which were plant-pathogenic and plant growth-enhancing bacteria, revealed unique utilization patterns and differences between closely related prey cells. An approximately 830-bp fragment of the 16S rRNA genes of all of theBdellovibrio strains used was obtained by PCR amplification by using a Bdellovibrio-specific primer combination. Soil and common bean rhizosphere strains produced two and one restriction patterns for this PCR product, respectively. The 16S rRNA genes of three soil isolates and three root-associated isolates were sequenced. One soil isolate belonged to theBdellovibrio stolpii-Bdellovibrio starrii clade, while all of the other isolates clustered withBdellovibrio bacteriovorus and formed two distantly related, heterogeneous groups.

scholarly journals rDNA analyses of planktonic heterocystous cyanobacteria, including members of the genera Anabaenopsis and Cyanospira The GenBank accession numbers of the 16S rDNA gene sequences reported in this paper are AY038032–AY038037.

Microbiology ◽  
2002 ◽  
Vol 148 (2) ◽  
pp. 481-496 ◽  
Author(s):  
Isabelle Iteman ◽  
Rosmarie Rippka ◽  
Nicole Tandeau de Marsac ◽  
Michael Herdman
Keyword(s):  
16S Rrna ◽  
16S Rdna ◽  
Genomic Sequence ◽  
Sequence Similarity ◽  
16S Rrna Genes ◽  
Rrna Genes ◽  
23S Rrna ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Heterocystous Cyanobacteria

The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphanizomenon flos-aquae, Nodularia sp. and two alkaliphilic planktonic members of the genera Anabaenopsis and Cyanospira, whose phylogenetic position was previously unknown. Comparison of the data with those previously published for individual groups of planktonic heterocystous cyanobacteria showed that, with the exception of members assigned to the genus Cylindrospermopsis, all the planktonic strains form a distinct subclade within the monophyletic clade of heterocystous cyanobacteria. Within this subclade five different phylogenetic clusters were distinguished. The phylogenetic groupings of Anabaena and Aphanizomenon strains within three of these clusters were not always consistent with their generic or specific assignments based on classical morphological definitions, and the high degree of sequence similarity between strains of Anabaenopsis and Cyanospira suggests that they may be assignable to a single genus. Ribotyping and additional studies performed on PCR amplicons of the 16S rDNA or the ITS for the 11 planktonic heterocystous strains demonstrated that they all contain multiple rrn operons and ITS regions of variable size. Finally, evidence is provided for intra-genomic sequence heterogeneity of the 16S rRNA genes within most of the individual isolates.

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