42 research outputs found

    Mucisphaera calidilacus gen. nov., sp. nov., a novel planctomycete of the class Phycisphaerae isolated in the shallow sea hydrothermal system of the Lipari Islands

    Get PDF
    For extending the current collection of axenic cultures of planctomycetes, we describe in this study the isolation and characterisation of strain Pan265(T) obtained from a red biofilm in the hydrothermal vent system close to the Lipari Islands in the Tyrrhenian Sea, north of Sicily, Italy. The strain forms light pink colonies on solid medium and grows as a viscous colloid in liquid culture, likely as the result of formation of a dense extracellular matrix observed during electron microscopy. Cells of the novel isolate are spherical, motile and divide by binary fission. Strain Pan265(T) is mesophilic (temperature optimum 30–33 °C), neutrophilic (pH optimum 7.0–8.0), aerobic and heterotrophic. The strain has a genome size of 3.49 Mb and a DNA G + C content of 63.9%. Phylogenetically, the strain belongs to the family Phycisphaeraceae, order Phycisphaerales, class Phycisphaerae. Our polyphasic analysis supports the delineation of strain Pan265(T) from the known genera in this family. Therefore, we conclude to assign strain Pan265(T) to a novel species within a novel genus, for which we propose the name Mucisphaera calidilacus gen. nov., sp. nov. The novel species is the type species of the novel genus and is represented by strain Pan265(T) (= DSM 100697(T) = CECT 30425(T)) as type strain

    Description of Polystyrenella longa gen. nov., sp. nov., isolated from polystyrene particles incubated in the Baltic Sea

    Get PDF
    Planctomycetes occur in almost all aquatic ecosystems on earth. They have a remarkable cell biology, and members of the orders Planctomycetales and Pirellulales feature cell division by polar budding, perform a lifestyle switch from sessile to motile cells and have an enlarged periplasmic space. Here, we characterise a novel planctomycetal strain, Pla110τ^{τ}, isolated from the surface of polystyrene particles incubated in the Baltic Sea. After phylogenetic analysis, the strain could be placed in the family Planctomycetaceae. Strain Pla110τ^{τ} performs cell division by budding, has crateriform structures and grows in aggregates or rosettes. The strain is a chemoheterotroph, grows under mesophilic and neutrophilic conditions, and exhibited a doubling time of 21 h. Based on our phylogenetic and morphological characterisation, strain Pla110τ^{τ} (DSM 103387τ^{τ} = LMG 29693τ^{τ}) is concluded to represent a novel species belonging to a novel genus, for which we propose the name Polystyrenella longa gen. nov., sp. nov

    Tautonia plasticadhaerens sp. nov., a novel species in the family Isosphaeraceae isolated from an alga in a hydrothermal area of the Eolian Archipelago

    Get PDF
    A novel planctomycetal strain, designated ElPT^{T}, was isolated from an alga in the shallow hydrothermal vent system close to Panarea Island in the Tyrrhenian Sea. Cells of strain ElPT^{T} are spherical, form pink colonies and display typical planctomycetal characteristics including division by budding and presence of crateriform structures. Strain ElPT^{T} has a mesophilic (optimum at 30 °C) and neutrophilic (optimum at pH 7.5) growth profile, is aerobic and heterotrophic. It reaches a generation time of 29 h (μmax_{max} = 0.024 h1^{-1}). The strain has a genome size of 9.40 Mb with a G + C content of 71.1% and harbours five plasmids, the highest number observed in the phylumPlanctomycetes thus far. Phylogenetically, the strain represents a novel species of the recently described genus Tautonia in the family Isosphaeraceae. A characteristic feature of the strain is ist tendency to attach strongly to a range of plastic surfaces. We thus propose the name Tautonia plasticadhaerens sp. nov. for the novel species, represented by the type strain ElPT^{T} (DSM 101012T^{T} = LMG 29141T^{T})

    Calycomorphotria hydatis gen. nov., sp. nov., a novel species in the family Planctomycetaceae with conspicuous subcellular structures

    Get PDF
    A novel strain belonging to the family Planctomycetaceae, designated V22T^{T}, was isolated from sediment of a seawater fish tank in Braunschweig, Germany. The isolate forms pink colonies on solid medium and displays common characteristics of planctomycetal strains, such as division by budding, formation of rosettes, a condensed nucleoid and presence of crateriform structures and fimbriae. Unusual invaginations of the cytoplasmic membrane and filamentous putative cytoskeletal elements were observed in thin sections analysed by transmission electron microscopy. Strain V22T^{T} is an aerobic heterotroph showing optimal growth at 30 °C and pH 8.5. During laboratory cultivations, strain V22T^{T} reached generation times of 10 h (maximal growth rate of 0.069 h1^{-1}). Its genome has a size of 5.2 Mb and a G + C content of 54.9%. Phylogenetically, the strain represents a novel genus and species in the family Planctomycetaceae, order Planctomycetales, class Planctomycetia. We propose the name Calycomorphotria hydatis gen. nov., sp. nov. for the novel taxon, represented by the type strain V22T^{T} (DSM 29767T^{T} = LMG 29080T^{T})

    Rosistilla oblonga gen. nov., sp. nov. and Rosistilla carotiformis sp. nov., isolated from biotic or abiotic surfaces in Northern Germany, Mallorca, Spain and California, USA

    Get PDF
    Planctomycetes are ubiquitous bacteria with fascinating cell biological features. Strains available as axenic cultures in most cases have been isolated from aquatic environments and serve as a basis to study planctomycetal cell biology and interactions in further detail. As a contribution to the current collection of axenic cultures, here we characterise three closely related strains, Poly24T^{T}, CA51T^{T} and Mal33, which were isolated from the Baltic Sea, the Pacific Ocean and the Mediterranean Sea, respectively. The strains display cell biological features typical for related Planctomycetes, such as division by polar budding, presence of crateriform structures and formation of rosettes. Optimal growth was observed at temperatures of 30–33 °C and at pH 7.5, which led to maximal growth rates of 0.065–0.079 h1^{-1}, corresponding to generation times of 9–11 h. The genomes of the novel isolates have a size of 7.3–7.5 Mb and a G + C content of 57.7–58.2%. Phylogenetic analyses place the strains in the family Pirellulaceae and suggest that Roseimaritima ulvae and Roseimaritima sediminicola are the current closest relatives. Analysis of five different phylogenetic markers, however, supports the delineation of the strains from members of the genus Roseimaritima and other characterised genera in the family. Supported by morphological and physiological differences, we conclude that the strains belong to the novel genus Rosistilla gen. nov. and constitute two novel species, for which we propose the names Rosistilla carotiformis sp. nov. and Rosistilla oblonga sp. nov. (the type species). The two novel species are represented by the type strains Poly24T^{T} (= DSM 102938T^{T} = VKM B-3434T^{T} = LMG 31347T^{T} = CECT 9848T^{T}) and CA51T^{T} (= DSM 104080T^{T} = LMG 29702T^{T}), respectively

    Physiological responses of crop plants against Trichoderma harzianum in saline environment

    Get PDF
    The physiological response of crop plants against Trichoderma harzianum (Th-6) in a saline habitat was studied. Trichoderma harzianum (Th-6) is an endophytic fungus that shows salt tolerance and establishes a symbiotic relationship with a host plant. To evaluate the role of Trichoderma harzianum (Th-6) in mitigating the consequences of salinity stress on crop plants, seeds of maize and rice were coated with Trichoderma before sowing and salt treatment. Later, after germination, twenty-one day old seedlings were subjected to NaCl concentrations (50, 100 and 150 mM). Salinity negatively affected all investigated physiological parameters in both crops. Treatment of seeds with Trichoderma improved plant growth and Th-treated plants exhibited substantial physiological adjustment in a saline environment compared to Th-untreated plants. The Th-treated plants under salt stress showed higher relative water content and stomatal conductance, better photosynthetic performance and higher pigment concentrations, as well as higher catalase and superoxide dismutase activities. Moreover, proline content in salt stress environment was higher in Th-treated plants, while H2O2 content declined. The physiological role of Trichoderma harzianum in mitigating the salt related consequences of both crop plants is discussed

    The efficacy of 'Radio guided Occult Lesion Localization' (ROLL) versus 'Wire-guided Localization' (WGL) in breast conserving surgery for non-palpable breast cancer: A randomized clinical trial – ROLL study

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>With the increasing number of non palpable breast carcinomas, the need of a good and reliable localization method increases. Currently the wire guided localization (WGL) is the standard of care in most countries. Radio guided occult lesion localization (ROLL) is a new technique that may improve the oncological outcome, cost effectiveness, patient comfort and cosmetic outcome. However, the studies published hitherto are of poor quality providing less than convincing evidence to change the current standard of care.</p> <p>The aim of this study is to compare the ROLL technique with the standard of care (WGL) regarding the percentage of tumour free margins, cost effectiveness, patient comfort and cosmetic outcome.</p> <p>Methods/design</p> <p>The ROLL trial is a multi center randomized clinical trial. Over a period of 2–3 years 316 patients will be randomized between the ROLL and the WGL technique. With this number, the expected 15% difference in tumour free margins can be detected with a power of 80%. Other endpoints include cosmetic outcome, cost effectiveness, patient (dis)comfort, degree of difficulty of the procedures and the success rate of the sentinel node procedure.</p> <p>The rationale, study design and planned analyses are described.</p> <p>Trial Registration</p> <p>(<url>http://www.clinicaltrials.gov</url>, study protocol number NCT00539474)</p

    Collagen fleeces do not improve colonic anastomotic strength but increase bowel obstructions in an experimental rat model

    Get PDF
    To investigate whether a collagen fleece kept in place by fibrin glue might seal off a colorectal anastomosis, provide reinforcement, and subsequently improve anastomotic healing. Wistar rats underwent a 1-cm left-sided colonic resection followed by a 4-suture end-to-end anastomosis. They were then randomly assigned to one of three treatment groups: no additional intervention (control, n = 20), the anastomosis covered with fibrin glue (fibrin glue, n = 20), the anastomosis covered with a collagen fleece, kept in place with fibrin glue (collagen fleece, n = 21). At either 3 or 7 days follow-up, anastomotic bursting pressure was measured and tissue was obtained for histology and collagen content assessment after which animals were sacrificed. Three rats in the control (15%), three in the fibrin glue (15%), and one in the collagen group (4.8%) died due to anastomotic complications (P = 0.497). Anastomotic bursting pressures were not significantly different between groups at 3 and 7 days follow-up (P = 0.659 and P = 0.427, respectively). However, bowel obstructions occurred significantly more often in the collagen group compared to the control group (14/21 vs. 3/20, P = 0.003). Collagen contents were not different between groups, but histology showed a more severe inflammation in the collagen group compared to the other groups at both 3 and 7 days follow-up. A collagen fleece kept in place by fibrin glue does not improve healing of colonic anastomoses in rats. Moreover, this technique induces significantly more bowel obstructions in rats, warranting further study before being translated to a clinical settin

    Non-essentiality of canonical cell division genes in the planctomycete Planctopirus limnophila

    No full text
    Most bacteria divide by binary fission using an FtsZ-based mechanism that relies on a multi-protein complex, the divisome. In the majority of non-spherical bacteria another multi-protein complex, the elongasome, is also required for the maintenance of cell shape. Components of these multi-protein assemblies are conserved and essential in most bacteria. Here, we provide evidence that at least three proteins of these two complexes are not essential in the FtsZ-less ovoid planctomycete bacterium Planctopirus limnophila which divides by budding. We attempted to construct P. limnophila knock-out mutants of the genes coding for the divisome proteins FtsI, FtsK, FtsW and the elongasome protein MreB. Surprisingly, ftsI, ftsW and mreB could be deleted without affecting the growth rate. On the other hand, the conserved ftsK appeared to be essential in this bacterium. In conclusion, the canonical bacterial cell division machinery is not essential in P. limnophila and this bacterium divides via budding using an unknown mechanism.This work was supported by BFU2016-78326-P and MDM-2016-0687, Spanish Ministerio de Economía y Competitividad. Also, part of this work was supported by a visiting scientist grant awarded to ERM by the Soehngen Institute of Anaerobic Microbiology (SIAM, project 024002002) of the Netherlands Organisation for Scientific Research (NWO). SHP is supported by the NWO grant ALWOP.308 and LC by the Spinoza prize awarded to Prof. dr. M.S.M. Jetten.Peer reviewe
    corecore