84 research outputs found

    Thiobacillus

    Get PDF
    File replaced (incorrect version) on 18/7/22 by KT (LDS) (1.4)Thi.o.ba.cil'lus. Gr. neut. n. theîon, sulfur, brimstone; L. masc. n. bacillus, a short rod, a short wand; N.L. masc. n. Thiobacillus, sulfur rodlet. Proteobacteria / Betaproteobacteria / Nitrosomonadales / Thiobacillaceae / Thiobacillus Cells are short rods. Cytochrome c oxidase‐positive and catalase‐positive when grown on thiosulfate. Gram‐stain‐negative. Endospores, exospores, and cysts are not produced. Metabolically obligate chemolithoautotrophs, supported by reduced sulfur species and elementary sulfur, and some methylated sulfur compounds. Genes encoding Form IAc, Form IAq, and Form II d‐ribulose 1,5‐bisphosphate carboxylase/oxygenases (RuBisCO) are present in the genomes. Carboxysomes are produced in some species and are repressed at high CO2 partial pressures. Volutin (polyphosphate) granules formed in most species. Produce tetrathionate as a detectable intermediate of thiosulfate oxidation. Obligately respiratory, with molecular oxygen and nitrate the only known terminal electron acceptors, with the latter only used in some species. Mesophilic, growing optimally at 25–32°C, and one psychrophilic species capable of growth down to −2°C. The major respiratory quinone is ubiquinone‐8 (UQ‐8). Dominant fatty acids are C16:0, C16:1, C15:0, and C17:1. DNA G + C content (mol%): 61.5–66.0. Type species: Thiobacillus thioparus Beijerinck 1904b, 153AL

    Viroids: survivors from the RNA world?

    Get PDF
    [EN] Because RNA can be a carrier of genetic information and a biocatalyst, there is a consensus that it emerged before DNA and proteins, which eventually assumed these roles and relegated RNA to intermediate functions. If such a scenario¿the so-calledRNAworld¿existed,wemight hope to find its relics in our presentworld. The properties of viroids that make them candidates for being survivors of the RNA world include those expected for primitive RNA replicons: (a) small size imposed by error-prone replication, (b) high G + C content to increase replication fidelity, (c) circular structure for assuring complete replication without genomic tags, (d ) structural periodicity for modular assembly into enlarged genomes, (e) lack of protein-coding ability consistent with a ribosome-free habitat, and ( f ) replication mediated in some by ribozymes, the fingerprint of the RNA world. With the advent of DNA and proteins, those protoviroids lost some abilities and became the plant parasites we now know.R.F. has received funding by grant BFU2011-28443 from Ministerio de Economia y Competititvidad (MINECO, Spain), R.S. by grants BFU2011-25271 (MINECO) and ERC-2011-StG-281191-VIRMUT (European Research Council), and S.F.E. by grant BFU2012-30805 (MINECO). P.S. has been supported by postdoctoral contracts from Generalitat Valenciana (APOSTD/2010, program VALi+d) and MINECO (program Juan de la Cierva).Flores Pedauye, R.; Gago Zachert, SP.; Serra Alfonso, P.; Sanjuan Verdeguer, R.; Elena Fito, SF. (2014). Viroids: survivors from the RNA world?. Annual Review of Microbiology. 68:395-414. https://doi.org/10.1146/annurev-micro-091313-103416S3954146

    The hidden world within plants: ecological and evolutionary considerations for defining functioning of microbial endophytes

    Get PDF
    All plants are inhabited internally by diverse microbial communities comprising bacterial, archaeal, fungal, and protistic taxa. These microorganisms showing endophytic lifestyles play crucial roles in plant development, growth, fitness, and diversification. The increasing awareness of and information on endophytes provide insight into the complexity of the plant microbiome. The nature of plant-endophyte interactions ranges from mutualism to pathogenicity. This depends on a set of abiotic and biotic factors, including the genotypes of plants and microbes, environmental conditions, and the dynamic network of interactions within the plant biome. In this review, we address the concept of endophytism, considering the latest insights into evolution, plant ecosystem functioning, and multipartite interactions.EU Cost Action [FA1103, 312117]; FWF (Austrian Science Foundation) [P26203-B22, P24569-B25]; Portuguese FCT (Foundation for Science and Technology) [SFRH/BPD/78931/2011]info:eu-repo/semantics/publishedVersio

    Bacteria-inducing legume nodules involved in the improvement of plant growth, health and nutrition

    Get PDF
    Bacteria-inducing legume nodules are known as rhizobia and belong to the class Alphaproteobacteria and Betaproteobacteria. They promote the growth and nutrition of their respective legume hosts through atmospheric nitrogen fixation which takes place in the nodules induced in their roots or stems. In addition, rhizobia have other plant growth-promoting mechanisms, mainly solubilization of phosphate and production of indoleacetic acid, ACC deaminase and siderophores. Some of these mechanisms have been reported for strains of rhizobia which are also able to promote the growth of several nonlegumes, such as cereals, oilseeds and vegetables. Less studied are the mechanisms that have the rhizobia to promote the plant health; however, these bacteria are able to exert biocontrol of some phytopathogens and to induce the plant resistance. In this chapter, we revised the available data about the ability of the legume nodule-inducing bacteria for improving the plant growth, health and nutrition of both legumes and nonlegumes. These data showed that rhizobia meet all the requirements of sustainable agriculture to be used as bio-inoculants allowing the total or partial replacement of chemicals used for fertilization or protection of crops

    De Mechanische Verklaring in de Physiologie

    No full text
    corecore