scholarly journals “Candidatus Bacilloplasma,” a Novel Lineage of Mollicutes Associated with the Hindgut Wall of the Terrestrial Isopod Porcellio scaber (Crustacea: Isopoda)

2007 ◽  
Vol 73 (17) ◽  
pp. 5566-5573 ◽  
Author(s):  
Rok Kostanjšek ◽  
Jasna Štrus ◽  
Gorazd Avguštin
Keyword(s):  
Electron Microscopy ◽  
Sequence Similarity ◽  
Mycoplasma Hominis ◽  
Sister Group ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Porcellio Scaber ◽  
Terrestrial Isopod ◽  
Transmission Electron ◽  
A Cell

ABSTRACT Pointed, rod-shaped bacteria colonizing the cuticular surface of the hindgut of the terrestrial isopod crustacean Porcellio scaber (Crustacea: Isopoda) were investigated by comparative 16S rRNA gene sequence analysis and electron microscopy. The results of phylogenetic analysis, and the absence of a cell wall, affiliated these bacteria with the class Mollicutes, within which they represent a novel and deeply branched lineage, sharing less than 82.6% sequence similarity to known Mollicutes. The lineage has been positioned as a sister group to the clade comprising the Spiroplasma group, the Mycoplasma pneumoniae group, and the Mycoplasma hominis group. The specific signature sequence was identified and used as a probe in in situ hybridization, which confirmed that the retrieved sequences originate from the attached rod-shaped bacteria from the hindgut of P. scaber and made it possible to detect these bacteria in their natural environment. Scanning and transmission electron microscopy revealed a spherically shaped structure at the tapered end of the rod-shaped bacteria, enabling their specific and exclusive attachment to the tip of the cuticular spines on the inner surface of the gut. Specific adaptation to the gut environment, as well as phylogenetic positioning, indicate the long-term association and probable coevolution of the bacteria and the host. Taking into account their pointed, rod-shaped morphology and their phylogenetic position, the name “Candidatus Bacilloplasma” has been proposed for this new lineage of bacteria specifically associated with the gut surface of P. scaber.

scholarly journals Canibacter oris gen. nov., sp. nov., isolated from an infected human wound

2014 ◽  
Vol 64 (Pt_5) ◽  
pp. 1635-1640 ◽  
Author(s):  
M. Aravena-Román ◽  
T. J. J. Inglis ◽  
C. Siering ◽  
P. Schumann ◽  
A. F. Yassin
Keyword(s):  
Sequence Similarity ◽  
Molecular Genetic ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Content Type ◽  
Phenotypic Differences ◽  
Link Type ◽  
Novel Genus And Species ◽  
Chemical Studies ◽  
A Cell

A facultatively anaerobic, Gram-reaction-positive, catalase- and oxidase-negative, rod-shaped bacterium isolated from an infected human wound caused by a dog bite was characterized by phenotypic and molecular genetic methods. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain IMMIB Q2029717T was a member of the order Micrococcales of the class Actinobacteria , displaying 91.6 % to 96 % sequence similarity with members of the family Microbacteriaceae . Phylogentic trees generated by different algorithms indicated that the strain forms an independent phylogenetic line of descent that consistently clustered proximal to the base of the genus Leucobacter . Chemical studies revealed the presence of a cell-wall murein based on l-lysine (type B1α), major menaquinone (MK-10) and a DNA G+C content of 56.9 mol%. The distinct phylogenetic position, ribotyping and matrix-assisted laser desorption/ionization time-of-flight MS profiles and the significant phenotypic differences clearly separate strain IMMIB Q2029717T from its nearest phylogenetic neighbour and support its classification as a representative of a novel genus and species, with the suggested name Canibacter oris gen. nov., sp. nov. The type strain is IMMIB Q2029717T ( = DSM 27064T = CCUG 64069T).

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.

Some Unique Features in Compound Eyes of Two Isopods

1972 ◽  
Vol 30 ◽  
pp. 48-49
Author(s):  
Paula Nemanic
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Suture Line ◽  
Compound Eyes ◽  
Porcellio Scaber ◽  
Crystalline Cone ◽  
Trichoid Sensilla ◽  
Terrestrial Isopod ◽  
Transmission Electron ◽  
Dioptric Apparatus

I have observed certain unique features in the ultrastructure of the compound eyes of the terrestrial isopod crustaceans Porcellio scaber and Armadillidium vulgare, using both scanning and transmission electron microscopy.Only about twenty ommatidia, arranged into four rows, constitute an eye, giving the organ the appearance of a cluster of grapes (Fig. 1). A few trichoid sensilla are interspersed between the ommatidia.The dioptric apparatus of each ommatidium is composed of a biconvex, cuticular lens and an underlying spherical crystalline cone. In these isopods each crystalline cone is the secretion of only two cells (Fig. 2), rather than four as in most malacostracans. The suture line between the two cone hemispheres is always parallel to the long axis of the ommatidium.

Electrolytic synthesis of ZrSi/ZrC nanocomposites from ZrSiO4 and carbon black powder in molten salt

2020 ◽  
Vol 111 (7) ◽  
pp. 581-586
Author(s):  
Li Ming ◽  
Wu Xiufeng
Keyword(s):  
Electron Microscopy ◽  
High Temperature ◽  
Carbon Black ◽  
Molten Salt ◽  
Cell Voltage ◽  
Black Powder ◽  
X Ray ◽  
Carbon Black Powder ◽  
Transmission Electron ◽  
A Cell

Abstract ZrSi/ZrC nanocomposites have stable high-temperature properties, where conventional materials cannot meet increasingly demanding high-temperature environments. In this paper, the microstructure and electrochemical reduction mechanism of ZrSi/ZrC nanocomposites have been studied. A mixture of ZrSiO4 and carbon black powder was processed using ball grinding, sheet pressing, and sintering, and cylindrically-sintered sheet was prepared as the cathode for the electrolytic work. A high purity graphite rod was utilized as the anode.The microstructure of the electrolytic product was characterized and analyzed using X-ray diffraction, scanning electron microscopy equipped with energy-dispersive X-ray spectroscopy, and transmission electron microscopy. The experimental results showed that the diameter of the as-synthesized ZrSi/ ZrC fibers typically range between 100-400 nm when produced by the electrolysis of sintered pellets in equimolar CaCl2-NaCl molten salt at 850°C with a cell voltage of 2.8 V for 20 h under an argon atmosphere. The nanofibers were formed in core-shell microstructures that overlap and grow.

scholarly journals Permeabilization of rat hepatocytes with Staphylococcus aureus alpha-toxin.

1985 ◽  
Vol 100 (6) ◽  
pp. 1922-1929 ◽  
Author(s):  
B F McEwen ◽  
W J Arion
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Rat Hepatocytes ◽  
Alpha Toxin ◽  
Cellular Functions ◽  
Transmembrane Channel ◽  
Selective Permeability ◽  
Treatment Conditions ◽  
Transmission Electron ◽  
A Cell

Pathogenic staphylococci secrete a number of exotoxins, including alpha-toxin. alpha-Toxin induces lysis of erythrocytes and liposomes when its 3S protein monomers associate with the lipid bilayer and form a hexomeric transmembrane channel 3 nm in diameter. We have used alpha-toxin to render rat hepatocytes 93-100% permeable to trypan blue with a lactate dehydrogenase leakage less than or equal to 22%. Treatment conditions included incubation for 5-10 min at 37 degrees C and pH 7.0 with an alpha-toxin concentration of 4-35 human hemolytic U/ml and a cell concentration of 13-21 mg dry wt/ml. Scanning electron microscopy revealed signs of swelling in the treated hepatocytes, but there were no large lesions or gross damage to the cell surface. Transmission electron microscopy indicated that the nucleus, mitochondria, and cytoplasm were similar in control and treated cells and both had large regions of well-defined lamellar rough endoplasmic reticulum. Comparisons of the mannose-6-phosphatase and glucose-6-phosphatase activities demonstrated that 5-10 U/ml alpha-toxin rendered cells freely permeable to glucose-6-phosphate, while substantially preserving the selective permeability of the membranes of the endoplasmic reticulum and the functionality of the glucose-6-phosphatase system. Thus, alpha-toxin appears to have significant potential as a means to induce selective permeability to small ions. It should make possible the study of a variety of cellular functions in situ.

scholarly journals Antricoccus suffuscus gen. nov., sp. nov., isolated from a natural cave

2015 ◽  
Vol 65 (Pt_12) ◽  
pp. 4410-4416 ◽  
Author(s):  
Soon Dong Lee
Keyword(s):  
Type Strain ◽  
New Genus ◽  
Novel Species ◽  
Sequence Similarity ◽  
Diaminopimelic Acid ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Diamino Acid ◽  
Unknown Phospholipid

A novel actinobacterium, designated strain C4-31T, was isolated from soil collected from a cave. Cells were aerobic, Gram-reaction-positive, oxidase-negative, catalase-positive and non-motile cocci. Comparison of 16S rRNA gene sequences showed that the organism occupied a distinct phylogenetic position within the suborder Frankineae, with sequence similarity values of less than 93.2 % to members of this suborder. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The major menaquinone was MK-9(H4). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, an unknown aminophospholipid and an unknown phospholipid. The major fatty acids were iso-C16 : 0, C17 : 1ω6c and C16 : 0. The G+C content of the DNA was 62.8 mol%. On the basis of morphological and chemotaxonomic data as well as phylogenetic evidence, strain C4-31T ( = KCTC 39556T = DSM 100065T) is considered to represent the type strain of a novel species of a new genus in the suborder Frankineae, for which the name Antricoccus suffuscus gen. nov., sp. nov. is proposed.

scholarly journals Alkalibacterium subtropicum sp. nov., a slightly halophilic and alkaliphilic marine lactic acid bacterium isolated from decaying marine algae

2011 ◽  
Vol 61 (12) ◽  
pp. 2996-3002 ◽  
Author(s):  
Morio Ishikawa ◽  
Kazuyuki Nakajima ◽  
Shihomi Ishizaki ◽  
Kayo Kodama ◽  
Akiko Okamoto-Kainuma ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Marine Algae ◽  
Sequence Similarity ◽  
Distinct Species ◽  
Molar Ratio ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Optimum Growth ◽  
Cultivation Conditions ◽  
Dna Relatedness

Two novel strains of marine lactic acid bacteria, isolated from decaying marine algae collected from a subtropical area of Japan, are described. The isolates, designated O24-2T and O25-2, were Gram-positive, non-sporulating and non-motile. They lacked catalase and quinones. Under anaerobic cultivation conditions, lactate was produced from glucose with the production of formate, acetate and ethanol in a molar ratio of approximately 2 : 1 : 1. Under aerobic cultivation conditions, acetate and lactate were produced from carbohydrates and related compounds. The isolates were slightly halophilic, highly halotolerant and alkaliphilic. They were able to grow in 0–17.0 % (w/v) NaCl, with optimum growth of strains O24-2T and O25-2 at 1.0–3.0 and 1.0–2.0 % (w/v) NaCl, respectively. Growth of strain O24-2T was observed at pH 7.5–9.5, with optimum growth at pH 8.0–8.5. Comparative 16S rRNA gene sequence analysis revealed that the isolates occupied a phylogenetic position within the genus Alkalibacterium, showing highest similarity (99.6 %) to Alkalibacterium putridalgicola T129-2-1T. Although sequence similarity was high, the DNA–DNA relatedness value between strain O24-2T and A. putridalgicola T129-2-1T was 27 %, indicating that they are members of distinct species. The DNA G+C contents of O24-2T and O25-2 were 43.7 and 44.4 mol%, respectively, and DNA–DNA relatedness between the isolates was 89 %. The cell-wall peptidoglycan was type A4β, Orn-d-Asp. The major cellular fatty acid components were C14 : 0, C16 : 0 and C16 : 1ω9c. Based on phenotypic characteristics and genetic distinctiveness, the isolates were classified as representatives of a novel species within the genus Alkalibacterium, for which the name Alkalibacterium subtropicum sp. nov. is proposed; the type strain is O24-2T ( = DSM 23664T = NBRC 107172T).

scholarly journals Thermoflavifilum aggregans gen. nov., sp. nov., a thermophilic and slightly halophilic filamentous bacterium from the phylum Bacteroidetes

2014 ◽  
Vol 64 (Pt_4) ◽  
pp. 1264-1270 ◽  
Author(s):  
Heike Anders ◽  
Peter F. Dunfield ◽  
Kirill Lagutin ◽  
Karen M. Houghton ◽  
Jean F. Power ◽  
...  
Keyword(s):  
Type Species ◽  
Sequence Similarity ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Total Lipid Extract ◽  
Strictly Aerobic ◽  
Respiratory Quinone ◽  
Content Type ◽  
Link Type ◽  
Heated Soil

A strictly aerobic, thermophilic, moderately acidophilic, non-spore-forming bacterium, strain P373T, was isolated from geothermally heated soil at Waikite, New Zealand. Cells were filamentous rods, 0.2–0.4 µm in diameter and grew in chains up to 80 µm in length. On the basis of 16S rRNA gene sequence similarity, strain P373T was shown to belong to the family Chitinophagaceae (class Sphingobacteriia ) of the phylum Bacteroidetes , with the most closely related cultivated strain, Chitinophaga pinensis UQM 2034T, having 87.6 % sequence similarity. Cells stained Gram-negative, and were catalase- and oxidase-positive. The major fatty acids were i-15 : 0 (10.8 %), i-17 : 0 (24.5 %) and i-17 : 0 3-OH (35.2 %). Primary lipids were phosphatidylethanolamine, two unidentified aminolipids and three other unidentified polar lipids. The presence of sulfonolipids (N-acyl-capnines) was observed in the total lipid extract by mass spectrometry. The G+C content of the genomic DNA was 47.3 mol% and the primary respiratory quinone was MK-7. Strain P373T grew at 35–63 °C with an optimum temperature of 60 °C, and at pH 5.5–8.7 with an optimum growth pH of 7.3–7.4. NaCl tolerance was up to 5 % (w/v) with an optimum of 0.1–0.25 % (w/v). Cell colonies were non-translucent and pigmented vivid yellow–orange. Cells displayed an oxidative chemoheterotrophic metabolism. The distinct phylogenetic position and the phenotypic characteristics separate strain P373T from all other members of the phylum Bacteroidetes and indicate that it represents a novel species in a new genus, for which the name Thermoflavifilum aggregans gen. nov., sp. nov. is proposed. The type strain of the type species is P373T ( = ICMP 20041T = DSM 27268T).

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.

scholarly journals Amphibacillus jilinensis sp. nov., a facultatively anaerobic, alkaliphilic bacillus from a soda lake

2010 ◽  
Vol 60 (11) ◽  
pp. 2540-2543 ◽  
Author(s):  
Xiao-Yue Wu ◽  
Gang Zheng ◽  
Wen-Wu Zhang ◽  
Xue-Wei Xu ◽  
Min Wu ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Soda Lake ◽  
Soluble Starch ◽  
Biochemical Properties ◽  
Phylogenetic Position ◽  
Rrna Gene ◽  
Positive Staining ◽  
Strictly Anaerobic ◽  
Dna Relatedness ◽  
Facultatively Anaerobic

A facultatively anaerobic, alkaliphilic, spore-forming, Gram-positive-staining rod, designated Y1T, was isolated under strictly anaerobic conditions from sediment of a soda lake in Jilin province, China. The strain was not dependent on Na+ but was highly halotolerant and grew optimally in medium JY with 0.5 M Na+ (0.06 M NaHCO3 and 0.44 M NaCl). The optimum pH for growth was 9.0, with a range of pH 7.5–10.5. No growth occurred at pH 7.0 or 11.0. The strain was mesophilic, with a temperature range of 15–45 °C and optimum growth at 32 °C. Strain Y1T was able to use certain mono- and oligosaccharides. Soluble starch and casein were hydrolysed. The methyl red test, Voges–Proskauer test and tests for catalase and oxidase activities were negative. The predominant fatty acids were anteiso-C15 : 0 and iso-C15 : 0. Comparative 16S rRNA gene sequence analysis revealed 93.4–96.8 % sequence similarity to members of the genus Amphibacillus. The DNA G+C content was 37.7 mol% (T m method). The DNA–DNA relatedness of strain Y1T with respect to Amphibacillus tropicus DSM 13870T and Amphibacillus sediminis DSM 21624T was 48 and 37 %, respectively. On the basis of its phylogenetic position and the DNA–DNA relatedness data as well as its physiological and biochemical properties, strain Y1T represents a novel species of the genus Amphibacillus, for which the name Amphibacillus jilinensis sp. nov. is proposed. The type strain is Y1T (=CGMCC 1.5123T =JCM 16149T).

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