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    31833 results match your criteria Applied and Environmental Microbiology[Journal]

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    Biological Containment of Genetically Modified Bacillus subtilis.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    School of Biological Sciences, Royal Holloway University of London, Egham, Surrey, TW20 OEX, UK.
    Genetic manipulation of bacterial spores of the genus Bacillus has shown potential for vaccination and for delivery of drugs or enzymes. Remarkably, proteins displayed on the spore surface retain activity and generally are not degraded. The heat stability of spores coupled with their desiccation resistance makes them suitable for delivery to humans or to animals by the oral route. Read More

    Molecular characterization of an Endozoicomonas-like organism causing infection in king scallop Pecten maximus L.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Cefas Weymouth Laboratory, Centre for Environment, Fisheries and Aquaculture Science, Weymouth, Dorset, DT4 8UB. United Kingdom.
    One of the fastest growing fisheries in the UK is the king scallop Pecten maximus L., also currently rated as the second most valuable. Mass mortality events in scallops have been reported world-wide, often with the causative agent(s) remaining uncharacterized. Read More

    Multi-omics reveal the lifestyle of the acidophilic, mineral-oxidizing model species Leptospirillum ferriphilum(T).
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Centre for Ecology and Evolution in Microbial Model Systems, Linnaeus University, Kalmar, Sweden
    Leptospirillum ferriphilum plays a major role in acidic, metal rich environments where it represents one of the most prevalent iron oxidizers. These milieus include acid rock and mine drainage as well as biomining operations. Despite its perceived importance, no complete genome sequence of this model species' type strain is available, limiting the possibilities to investigate the strategies and adaptations Leptospirillum ferriphilum(T) applies to survive and compete in its niche. Read More

    dRNA-seq implicates sulfide as master regulator of S(0) metabolism in Chlorobaculum tepidum and other green sulfur bacteria.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    School of Marine Science and Policy, University of Delaware, Newark, DE U.S.A.
    The green sulfur bacteria (Chlorobiaceae) are anaerobes that use electrons from reduced sulfur compounds (sulfide, S(0), and thiosulfate) as electron donors for photoautotrophic growth. Chlorobaculum tepidum, the model system for the Chlorobiaceae, both produces and consumes extracellular S(0) globules depending on the availability of sulfide in the environment. These physiological changes imply significant changes in gene regulation, which has been observed when sulfide is added to Cba. Read More

    Loop of Streptomyces feruloyl esterase plays an important role in its activity of releasing ferulic acid from biomass.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Research Institute for Biological Sciences (RIBS), Okayama Prefectural Technology Center for Agriculture, Forestry, and Fisheries, 7549-1 Kibichuo-cho, Kaga-gun, Okayama 716-1241, Japan
    Feruloyl esterases (FAEs) are key enzymes required for the production of ferulic acid from agricultural biomass. Previously, we identified and characterized R18, an FAE from Streptomyces cinnamoneus NBRC 12852, which showed no sequence similarity with the known FAEs. To determine the region involved in its catalytic activity, we constructed chimeric enzymes using R18 and its homolog (TH2-18) from S. Read More

    Sinorhizobium meliloti glutathione reductase is required for both redox homeostasis and symbiosis.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, Shanghai 200444, China.
    Glutathione (L-γ-glutamyl-L-cysteinylglycine; GSH), one of the key antioxidants in Sinorhizobium meliloti, is required for the development of alfalfa (Medicago sativa) nitrogen-fixing nodules. Glutathione exists either in a reduced form (GSH) or an oxidized form (GSSG), and its content is regulated by two pathways in S. meliloti The first pathway is the de novo synthesis of glutathione from its constituent amino acids, namely, Glu, Cys, and Gly, catalyzed by γ-glutamyl cysteine synthetase (GshA) and glutathione synthetase (GshB). Read More

    High prevalence and genetic diversity of large phiCD211/phiCDIF1296T-like prophages in Clostridioides difficile.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Microbiology and Infectious Diseases, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, QC, Canada.
    Clostridioides difficile (formerly Clostridium difficile) is a pathogenic bacterium displaying great genetic diversity. A significant proportion of this diversity is due to the presence of integrated prophages. Here, we provide an in-depth analysis of phiCD211, also known as phiCDIF1296T, the largest phage identified in C. Read More

    A genetic system for the thermophilic acetogenic bacterium Thermoanaerobacter kivui.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Molecular Microbiology & Bioenergetics, Institute of Molecular Biosciences, Johann Wolfgang Goethe University, Frankfurt am Main, Germany.
    Thermoanaerobacter kivui is one of the very few thermophilic acetogenic microorganisms. It grows optimally at 66°C on sugars but also lithotrophically with H2 + CO2 or with CO, producing acetate as major product. While a genome-derived model of acetogenesis has been developed, only few physiological or biochemical experiments towards the function of important enzymes in carbon and energy metabolism have been carried out. Read More

    Sulfolobus acidocaldarius uptakes pentoses via a cut2-type ABC transporter and metabolizes them through the aldolase-independent Weimberg pathway.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Institute of Biology II, Molecular Biology of Archaea, University of Freiburg, Schaenzlestr.1, 79104 Freiburg, Germany
    Sulfolobus spp. possess a great metabolic versatility and grow heterotrophically on various carbon sources such as different sugars and peptides. Known sugar transporters in Archaea predominantly belong to ABC transport systems. Read More

    Characterization of Vibrio parahaemolyticus and Vibrio vulnificus Recovered from Oysters during an Oyster Relay Study.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    National Oceanic and Atmospheric Administration, National Centers for Coastal Ocean Science, Cooperative Oxford Lab, Oxford, MD 21654.
    Vibrio parahaemolyticus (Vp) and Vibrio vulnificus (Vv) are naturally occurring estuarine bacteria and are the leading causes of seafood-associated infections and mortality in the USA. Though multiple-antibiotic resistant Vp and Vv have been reported resistance patterns in vibrios are not as well documented as other food-borne bacterial pathogens. Salinity relaying (SR) is a Post-Harvest Processing (PHP) treatment to reduce the abundance of these pathogens in shellfish harvested during the warmer months. Read More

    The tape measure protein is involved in the heat stability of Lactococcus lactis phages.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Québec, Qc, Canada
    Virulent lactococcal phages are still a major risk for milk fermentation processes as they may lead to slowdowns and low quality fermented dairy products, particularly cheeses. Some of the phage control strategies used by the industry rely on heat treatments. Recently, a few Lactococcus lactis phages were found to be highly thermo-resistant. Read More

    Community composition and ultrastructure of a nitrate-dependent anaerobic methane-oxidizing enrichment culture.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Microbiology, IWWR, Faculty of Science, Radboud University, Nijmegen, the Netherlands
    Methane is a very potent greenhouse gas and can be oxidized aerobically or anaerobically through microbial-mediated processes, thus decreasing methane emissions to the atmosphere. Using a complementary array of methods including phylogenetic analysis, physiological experiments, and light and electron microscopy techniques (including electron tomography), we investigated the community composition and ultrastructure of a continuous bioreactor enrichment culture, in which anaerobic methane oxidation (AOM) was coupled to nitrate reduction. A membrane bioreactor was seeded with AOM biomass and continuously fed with excess methane. Read More

    Divalent metal cations potentiate the predatory capacity of amoeba for Cryptococcus neoformans.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD.
    Among the best studied interaction between soil phagocytic predators and a human pathogenic fungus is that of Acanthamoeba castellanii and Cryptococcus neoformans The experimental conditions used in amoeba-fungal confrontation assays can have major effects on whether the fungus or the protozoan is ascendant in the interaction. In the presence of Mg(2+) and Ca(2+) in PBS, C. neoformans was consistently killed when incubated with A. Read More

    The swinholide biosynthetic gene cluster from a terrestrial cyanobacterium Nostoc sp. UHCC 0450.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Food and Environmental Sciences, Viikki Biocenter 1, University of Helsinki, Helsinki, Finland
    Swinholides are 42-carbon ring polyketides with a twofold axis of symmetry. They are potent cytotoxins that disrupt the actin cytoskeleton. Swinholides were discovered from the marine sponge Theonella sp. Read More

    Cry64Ba and Cry64Ca, two ETX/MTX2 Bacillus thuringiensis insecticidal proteins against hemipteran pests.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, P. R. China
    Genetically modified crops that express insecticidal Bacillus thuringiensis (Bt) proteins have become a primary approach for control of lepidopteran (moth) and coleopteran (beetle) pests that feed by chewing the plants. However, the sap-sucking insects (Hemiptera) are not particularly susceptible to Bt toxins. In this study, we describe two Cry toxins (Cry64Ba and Cry64Ca) from a Bt 1012 strain showed toxicity against two important rice hemipteran pests, Laodelphax striatellus and Sogatella furcifera Both of these two proteins contain an ETX/MTX2 domain, and share common sequence features with the β-pore forming toxins. Read More

    Temporal stability of Escherichia coli concentrations in waters of two irrigation ponds in Maryland.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    USDA-ARS Environmental Microbial and Food Safety Laboratory, Beltsville, MD.
    Fecal contamination of water sources is an important water quality issue for agricultural irrigation ponds. Escherichia coli concentrations are commonly used to evaluate recreational and irrigation water quality. We hypothesized that there may exist temporally stable spatial patterns of E. Read More

    Carbon Amendments Alter Microbial Community Structure and Net Mercury Methylation Potential in Sediments.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, TN USA
    Neurotoxic methylmercury (MeHg) is produced by anaerobic Bacteria and Archaea possessing the genes hgcAB, but it is unknown how organic substrate and electron acceptor availability impact the distribution and abundance of these organisms. We evaluated the impact of organic substrate amendments on mercury (Hg) methylation rates, microbial community structure, and the distribution of hgcAB(+) microbes with sediments. Sediment slurries were amended with short-chain fatty acids, alcohols, or a polysaccharide. Read More

    Hyperthermophilic Carbamate Kinase Stability and Anabolic In Vitro Activity at Alkaline pH.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Research School of Chemistry, Australian National University, Canberra, Australia
    Carbamate kinases catalyze the conversion of carbamate to carbamoyl phosphate, which is readily transformed into other compounds. Carbamate forms spontaneously from ammonia and carbon dioxide in aqueous solutions, so the kinases have potential for sequestrative utilization of the latter compounds. Here, we compare seven carbamate kinases from mesophilic, thermophilic and hyperthermophilic sources. Read More

    glnA truncation in Salmonella enterica results in a small colony variant phenotype, attenuated host cell entry, and reduced expression of flagellin and SPI-1 associated effector genes.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Division of Bacterial Infections (FG11), Robert Koch-Institut, Wernigerode, Germany
    Many pathogenic bacteria use sophisticated survival strategies to overcome harsh environmental conditions. One is the formation of slow-growing subpopulations termed small colony variants (SCVs). Here we characterize an SCV, which spontaneously emerged from an axenic Salmonella enterica serovar Typhimurium water culture. Read More

    Dynamics of heterotrophic bacterial assemblages within Synechococcus cultures.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    State Key Laboratory for Marine Environmental Science, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, People's Republic of China.
    Interactions between photoautotrophic and heterotrophic microorganisms are central to the marine microbial ecosystem. Lab cultures of one of the dominant marine photoautotrophs, Synechococcus, have historically been difficult to render axenic, presumably because these bacteria depend upon other organisms to grow in these conditions. These tight associations between Synechococcus and heterotrophic bacteria represent a good, relevant system to study interspecies interactions. Read More

    Understanding Functional Roles of Native Pentose-Specific Transporters for Activating Dormant Pentose Metabolism in Yarrowia lipolytica.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, TN 37920
    Pentoses including xylose and arabinose are the second-most prevalent sugars of lignocellulosic biomass that can be harnessed for biological conversion. Although Yarrowia lipolytica has emerged as a promising industrial microorganism for production of high-value chemicals and biofuels, its native pentose metabolism is poorly understood. Our previous study demonstrated that Y. Read More

    Identification of a cheZ-like gene in Azorhizobium caulinodans, a key gene in the control of chemotaxis and colonization of the host plant.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, People's Republic of China
    Chemotaxis can provide bacteria with competitive advantages for survival in complex environments. The CheZ chemotaxis protein is a phosphatase, affecting the flagellar motor in Escherichia coli, by dephosphorylating the response regulator CheY-P protein responsible for clockwise rotation. A cheZ gene has been found in Azorhizobium caulinodans ORS571, in contrast to other rhizobial species studied so far. Read More

    Low molecular weight thiols and thioredoxins are important players in Hg(II) resistance in Thermus thermophilus HB27.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Department of Biochemistry and Microbiology, Rutgers University, USA.
    Mercury (Hg), one of the most toxic and widely distributed heavy metals, has a high affinity for thiol groups. Thiol groups reduce and sequester Hg. Therefore, low molecular weight and protein thiols may be important cell components used in Hg resistance. Read More

    Alginate Lyases: Diversity of Three Dimensional Structures and Catalytic Mechanisms.
    Appl Environ Microbiol 2017 Nov 17. Epub 2017 Nov 17.
    Marine Biotechnology Research Center, State Key Laboratory of Microbial Technology, Shandong University, Jinan 250100, China
    Alginate is a linear polysaccharide mainly produced by brown algae in marine environments. Alginate consists of a linear block copolymer made up of two monomeric units, β-d-mannuronate (M) and its C5 epimer α-l-guluronate (G). Alginate lyases are polysaccharide lyases (PL) that degrade alginate via a β-elimination reaction. Read More

    Correction for Borch-Pedersen et al., "Effects of High Pressure on Bacillus licheniformis Spore Germination and Inactivation".
    Appl Environ Microbiol 2017 Dec 16;83(23). Epub 2017 Nov 16.
    Department of Food Safety and Infection Biology, Faculty of Veterinary Medicine, the Norwegian University of Life Sciences, Oslo, Norway.

    Effects of lowered and enhanced glycogen pools on salt-induced sucrose production in a sucrose-secreting strain of Synechococcus elongatus PCC 7942.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, No. 189 Songling Road, Qingdao 266101, China.
    Sucrose and glycogen syntheses in cyanobacteria share the common precursor glucose-1-phosphate. It is generally assumed that lowering glycogen synthesis could drive more carbon towards sucrose synthesis that can be induced by salt stress among cyanobacteria. By using a theophyllin-dependent riboswitch system, the expression of glgC, a key gene in glycogen synthesis, was down-regulated in a quantitative manner in a sucrose-secreting strain of Synechococcus elongatus PCC 7942. Read More

    Porcine small and large intestinal microbiota rapidly hydrolyze the masked mycotoxin deoxynivalenol-3-glucoside and release deoxynivalenol in spiked batch cultures in vitro.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRA, ENVT, INP-Purpan, UPS, 180 chemin de Tournefeuille, 31027 Toulouse cedex 3, France.
    Mycotoxin contamination of cereal grains causes well-recognized toxicities in animals and humans, but the fate of plant-bound masked mycotoxins in the gut is less well understood. Masked mycotoxins have been found to be stable under conditions prevailing in the small intestine, but are rapidly hydrolyzed by fecal microbiota. This study aims to assess the hydrolysis of the masked mycotoxin deoxynivalenol-3-glucoside (DON3Glc) by microbiota of different regions of the porcine intestinal tract. Read More

    Expression of a Cellobiose Phosphorylase from Thermotoga maritima in Caldicellulosiruptor bescii Improves the Phosphorolytic Pathway and Results in a Dramatic Increase in Cellulolytic Activity.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Department of Genetics, University of Georgia, Athens, Georgia 30602, USA
    Members of the genus Caldicellulosiruptor have the ability to deconstruct and grow on lignocellulosic biomass without conventional pretreatment and a genetically tractable species, C. bescii, was recently engineered to produce ethanol directly from switchgrass. C. Read More

    Inter-dependence between primary metabolism and xenobiotic mitigation characterises the proteome of Bjerkandera adusta decomposing wood.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Department of Biosciences, Swansea University, Singleton Park, Swansea, SA2 8PP
    The aim of the current work was to identify key features of the fungal proteome involved in active decay of beech wood blocks, by the white rot fungus Bjerkandera adusta at 20°C and 24°C. A combination of protein and domain analyses ensured a high level of annotation, which revealed that while variation in the proteins identified was high between replicates, there was a considerable degree of functional conservation between the two temperatures. Further analysis revealed differences in the pathways and processes employed by the fungus at the different temperatures, particularly in relation to nutrient acquisition and xenobiotic mitigation. Read More

    Enhancing the thermostability of Rhizomucor miehei lipase with a limited screening library by rational design point mutations and disulfide bonds.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Key Laboratory of Molecular Biophysics, the Ministry of Education; College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
    Rhizomucor miehei lipase (RML), as a kind of eukaryotic protein catalyst, plays an important role in food, organic chemical, and biofuel industries. However, RML retains its catalytic activity below 50°C, which limits its industrial applications at higher temperatures. Soluble expression of this eukaryotic protein in Escherichia coli not only helps to screen for thermostable mutants quickly, but also provides the opportunity to develop rapid and effective ways to enhance the thermal stability of eukaryotic proteins. Read More

    Antifungal HSAF biosynthesis in Lysobacter enzymogenes is controlled by the interplay of two transcription factors and a diffusible molecule.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Institute of Plant Protection, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, P.R. China
    Lysobacter enzymogenes is a Gram-negative, environmental ubiquitous bacterium that produces a secondary metabolite, called HSAF (Heat-stable antifungal factor), as an antifungal factor against plant and animal fungal pathogens. 4-hydroxybenzoic acid (4-HBA) is a newly identified diffusible factor that regulates HSAF synthesis via LysRLe, a LysR-type transcription factor (TF). Here, to identify additional TFs within the 4-HBA regulatory pathway that control HSAF production, we re-analyzed the LenB2-based transcriptomic data, in which LenB2 is the enzyme responsible for 4-HBA production. Read More

    A stable core gut microbiota across fresh- to saltwater transition for farmed Atlantic salmon.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Faculty of Chemistry, Biotechnology and Food Science, University of Life Sciences, Ås, Norway.
    Gut microbiota associations through habitat transitions are fundamentally important, yet poorly understood. One such habitat transition is the migration from fresh to salt water for anadromous fish such as salmon. The aim of the current work was therefore to determine the fresh- to saltwater impact on the gut microbiota in farmed Atlantic salmon, with dietary interventions resembling that of fresh- and salt water diets with respect to fatty acid composition. Read More

    Population-wide survey of Salmonella enterica response to high pressure processing reveals a diversity of responses and tolerance mechanisms.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Bureau of Microbial Hazards, Health Canada, Ottawa, Ontario, Canada
    High pressure processing is a non-thermal method of food preservation that uses pressure to inactivate microorganisms. To ensure the effective validation of process parameters, it is important that the design of challenge protocols consider the potential for resistance in a particular species. Herein, the response of 99 diverse Salmonella enterica strains to high pressure is reported. Read More

    Genome-wide identification of fitness factors in mastitis-associated Escherichia coli.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, USA
    Virulence factors of mammary pathogenic Escherichia coli (MPEC) have not been identified, and it is not known how bacterial gene content influences severity of mastitis. Here, we report the first genome-wide identification of genes that contribute to fitness of MPEC in conditions relevant to the natural history of the disease. A highly virulent clinical isolate (M12) was identified that killed Galleria mellonella at low infectious doses and which replicated to high numbers in mouse mammary glands and spread to spleens. Read More

    Microbially mediated coupling of Fe and N cycles by nitrate-reducing Fe(II)-oxidizing bacteria in littoral freshwater sediments.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Geomicrobiology, Center for Applied Geosciences, University of Tübingen, Germany
    Nitrate-reducing iron(II)-oxidizing bacteria have been known for approximately 20 years. There has been much debate to which extent the reduction of nitrate and the oxidation of ferrous iron are coupled via enzymatic pathways or via abiotic processes induced by nitrite formed by heterotrophic denitrification. The aim of the present study was to assess the coupling of nitrate reduction and iron(II) oxidation by monitoring changes in substrate concentrations as well as in the activity of nitrate-reducing bacteria in natural littoral freshwater sediment as a response to a stimulation with nitrate and iron(II). Read More

    Year-round shotgun metagenomes reveal stable microbial communities in agricultural soils and novel ammonia oxidizers responding to fertilization.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Georgia Institute of Technology, Atlanta, Georgia, USA
    The dynamics of individual microbial populations and their gene functions in agricultural soils, especially after major activities such as nitrogen (N) fertilization, remain elusive but are important for better understanding nutrient cycling. Here, we analyzed 20 short-read metagenomes collected at four time points across one year from two depths (0-5 and 20-30 cm) in two Midwestern agricultural sites representing contrasting soil textures (sandy versus silty-loam), with similar cropping histories. Although microbial community taxonomic and functional compositions differed between the two locations and depths, they were more stable within a depth/site throughout the year than communities in natural water-based ecosystems. Read More

    Methicillin Resistant Staphylococcus aureus Sequence Type (ST) 5 Isolates from Health Care and Agricultural Sources Adhere Equivalently to Human Keratinocytes.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    National Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Ames, Iowa
    Staphylococcus aureus is part of the nasal microbiome of many humans and has become a significant public health burden due to infections with antibiotic resistant strains, including methicillin resistant S. aureus (MRSA). Several lineages of S. Read More

    Fecal microbiota transplant from highly feed efficient donors shows little effects on age-related changes in feed efficiency-associated fecal microbiota in chickens.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Institute of Animal Nutrition and Functional Plant Compounds, Department for Farm Animals and Veterinary Public Health, University of Veterinary Medicine Vienna, Vienna, Austria.
    Chickens of good and poor feed efficiency (FE) have been shown to differ in their intestinal microbiota composition. This study investigated differences in the fecal bacterial community of good and poor feed efficient chickens at 16 and 29 days post-hatch (dph) and evaluated whether a fecal microbiota transplant (FMT) from feed efficient donors early in life can affect the fecal microbiota in chickens at 16 and 29 dph, chicken's FE and nutrient retention at four weeks of age. One-hundred-ten chickens were inoculated with a FMT or a control transplant (CT) on 1, 6 and 9 dph and ranked according to residual feed intake (RFI; metric for FE) on 30 dph. Read More

    Tinkering with osmotically controlled transcription allows enhanced production and excretion of ectoine and hydroxyectoine from a microbial cell factory.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Department of Biology, Laboratory for Microbiology, Philipps-University Marburg, D-35043 Marburg, Germany
    Ectoine and hydroxyectoine are widely synthesized by members of the Bacteria and a few Archaea as potent osmostress protectants. We have studied the salient features of the osmostress-responsive promoter directing the transcription of the ectoine/hydroxyectoine biosynthetic gene cluster from the plant-roots-associated bacterium Pseudomonas stutzeri by transferring it into Escherichia coli, an enterobacterium that does not produce ectoines naturally. Using ect-lacZ reporter fusions, we found that the heterologous ect promoter reacted with exquisite sensitivity in its transcriptional profile to graded increases in sustained high salinity, responded to a true osmotic signal, and required the build-up of an osmotically effective gradient across the cytoplasmic membrane for its induction. Read More

    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Loschmidt Laboratories, Research Centre for Toxic Compounds in the Environment RECETOX, Faculty of Science, Masaryk University, Kamenice 5/A13, 625 00 Brno, Czech Republic
    The haloalkane dehalogenase enzyme DmmA was identified by marine metagenomic screening. Determination of its crystal structure revealed an unusually large active site compared to previously characterized haloalkane dehalogenases. Here we present a biochemical characterization of this interesting enzyme with emphasis on its structure-function relationships. Read More

    Distribution and phylogeny of microsymbionts associated with cowpea (Vigna unguiculata) nodulation in three agro-ecological regions of Mozambique.
    Appl Environ Microbiol 2017 Nov 3. Epub 2017 Nov 3.
    Department of Chemistry, Tshwane University of Technology, Arcadia campus, Pretoria, South Africa
    Cowpea derives most of its N nutrition from biological nitrogen fixation (BNF) via symbiotic bacteroids in root nodules. In Sub-Saharan Africa, the diversity and biogeo-graphic distribution of bacterial microsymbionts nodulating cowpea and other indigenous legumes are not well understood, though needed for increased legume production. The aim of this study was to describe rhizobial distribution and their phylogenies at different agro-ecological regions of Mozambique using BOX-PCR, ITS-RFLP and sequence analysis of housekeeping genes. Read More

    Plasticity of the pyruvate node modulates hydrogen peroxide production and acid tolerance in multiple oral streptococci.
    Appl Environ Microbiol 2017 Oct 27. Epub 2017 Oct 27.
    Department of Restorative Dentistry, Oregon Health and Science University, Portland, OR, USA.
    Commensal Streptococcus sanguinis and Streptococcus gordonii are pioneer oral biofilm colonizers. Characteristic for both is the SpxB-dependent production of H2O2, which is crucial for inhibiting competing biofilm members, especially the cariogenic species Streptococcus mutans H2O2 production is strongly impacted by environmental conditions, yet few mechanisms are known. Dental plaque pH is one of the key parameters dictating dental plaque ecology, and ultimately oral health status. Read More

    Neutralizing anti-STa antibodies derived from enterotoxigenic Escherichia coli (ETEC) toxoid fusions with heat-stable toxin (STa) mutant STaN12S, STaL9A/N12S or STaN12S/A14T show little cross-reactivity with guanylin or uroguanylin.
    Appl Environ Microbiol 2017 Oct 27. Epub 2017 Oct 27.
    Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, Kansas, USA 66506
    Heat-stable toxin (STa)-producing enterotoxigenic Escherichia coli (ETEC) strains are a top cause of moderate-to-severe diarrhea in children from developing countries and a common cause of travelers' diarrhea. Recent progress in using STa toxoids and toxoid fusions to induce neutralizing anti-STa antibodies accelerates ETEC vaccine development. However, concern remains whether the derived anti-STa antibodies cross-react with STa-like guanylin and uroguanylin, two GC-C ligands regulating the fluid and electrolyte transportation in human intestinal and renal epithelial cells. Read More

    F-specific RNA bacteriophages, especially members of subgroup II, should be reconsidered as good indicators of viral pollution of oysters.
    Appl Environ Microbiol 2017 Oct 27. Epub 2017 Oct 27.
    Université de Lorraine, LCPME (Laboratoire de Chimie Physique et Microbiologie pour l'Environnement), UMR 7564, Faculté de Pharmacie, Nancy F-54000, France
    Norovirus (NoV) is the leading cause of gastroenteritis outbreaks linked to oyster consumption. In this study, we investigated the potential of F-specific RNA bacteriophages (FRNAPH) as indicators of viral contamination in oysters, by focusing especially on the subgroup FRNAPH-II. These viral indicators have been neglected because of their sometimes different behavior from that of NoV in shellfish, especially during the depuration processes usually performed before marketing. Read More

    Compartmentalization of Carbaryl Degradation Pathway: Molecular Characterization of Inducible Periplasmic Carbaryl Hydrolase from Pseudomonas spp.
    Appl Environ Microbiol 2017 Oct 27. Epub 2017 Oct 27.
    Department of Biosciences and Bioengineering, Indian Institute of Technology-Bombay, Powai, Mumbai 400076, India.
    Pseudomonas sp. strains C5pp and C7 degrade carbaryl as the sole carbon source. Carbaryl hydrolase (CH) catalyzes the hydrolysis of carbaryl to 1-naphthol and methylamine. Read More

    Bioinformatics analysis and characterization of highly efficient polyvinyl alcohol (PVA)-degrading enzymes from the novel PVA degrader Stenotrophomonas rhizophila QL-P4.
    Appl Environ Microbiol 2017 Oct 27. Epub 2017 Oct 27.
    CAS Key Laboratory of Genome Sciences & Information, Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing, China
    Polyvinyl alcohol (PVA) is used widely in industry, and associated environmental pollution is a serious problem. Herein, we report a novel, efficient PVA degrader, Stenotrophomonas rhizophila QL-P4, isolated from fallen leaves from virgin forest in the Qinling Mountains. The complete genome was obtained using single-molecule real-time (SMRT) technology and corrected using Illumina sequencing. Read More

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