32,188 results match your criteria Applied and Environmental Microbiology[Journal]


Mechanism of virus inactivation by cold atmospheric-pressure plasma and plasma-activated water.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

State Key Laboratory of Electrical Insulation and Power Equipment, Center for Plasma Biomedicine, Xi'an Jiaotong University, Xi'an 710049, P. R. China

Viruses are serious pathogenic contamination that severely affect the environment and human health. Cold atmospheric-pressure plasma efficiently inactivates pathogenic bacteria, however, the mechanism of virus inactivation by plasma is not fully understood. In this study, surface plasma in argon mixed with 1% air and plasma-activated water were used to treat water containing bacteriophages. Read More

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Resuscitation promoting factors are required for biofilm formation in .

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

DST/NRF Centre of Excellence for Biomedical TB Research, Faculty of Health Sciences, University of the Witwatersrand, National Health Laboratory Service, Johannesburg, South Africa

Resuscitation promoting factors (Rpfs) have previously been shown to act as growth stimulatory molecules via their lysozyme-like activity on peptidoglycan in the bacterial cell wall. In this study, we investigated the ability of strains lacking genes to form biofilms and tested their susceptibility to cell wall targeting agents. encodes four distinct homologues, namely MSMEG_5700 (), MSMEG_5439 (), MSMEG_4640 () and MSMEG_4643 (). Read More

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June 2018
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A linear plasmid-like prophage of Promotes Biofilm Assembly.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

The Forsyth Institute, Cambridge, USA

The human oral cavity is home to a large number of bacteria and bacteriophages (phages). However, the biology of oral phages as members of the human microbiome is not well understood. Recently, we isolated an subsp. Read More

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Genome rearrangement shapes ecological adaptation.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

State Key Laboratory of Marine Environmental Science, College of Ocean and Earth Sciences, Institute of Marine Microbes and Ecospheres, Xiamen University, Xiamen 361102, PR China

is the most abundant and smallest known free-living photosynthetic microorganism and is a key player in marine ecosystems and biogeochemical cycles. can be broadly divided into high-light-adapted (HL) and low-light-adapted (LL) clades. In this study, we isolated two low-light-adapted I (LLI) strains from the western Pacific Ocean and obtained their genomic data. Read More

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Comparative genomics reveals robust phylogroups in the genus as the basis for reclassification.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

School of Microbiology and APC Microbiome Institute, University College Cork, Cork, Ireland.

The genus includes over 200 species that are widely used in fermented food preservation, biotechnology or that are explored for beneficial effects on health. Naming, classifying and comparing lactobacilli has been challenging due to the high level of phenotypic and genotypic diversity they display, and because of the uncertain degree of relatedness between them and associated genera. The aim of this study was to investigate the feasibility of dividing the genus into more homogeneous genera/clusters, exploiting genome-based data. Read More

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June 2018
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Characterisation of CapC, a novel autotransporter and virulence factor of .

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Pathology and Infectious Diseases, School of Veterinary Medicine, University of Surrey, Guildford, UK

is recognized as an important causative agent of bacterial gastroenteritis in the developed world. Despite the identification of several factors contributing to infection, characterization of the virulence strategies employed by remains a significant challenge. Bacterial autotransporter proteins are a major class of secretory proteins in Gram-negative bacteria and notably many autotransporter proteins contribute to bacterial virulence. Read More

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Microevolution of aquatic ST-261 from Australia indicates dissemination via imported tilapia and ongoing adaptation to marine hosts or environment.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

The University of Queensland, School of Biological Sciences and Centre for Marine Science, St Lucia Campus, Brisbane, Queensland, Australia

(GBS) causes disease in a wide range of animals. The serotype Ib lineage is highly adapted to aquatic hosts, exhibiting substantial genome reduction compared with terrestrial conspecifics. Here we sequence genomes from 40 GBS isolates including 25 from wild fish and captive stingrays in Australia, six local veterinary or human clinical isolates, and nine isolates from farmed tilapia in Honduras and compare with 42 genomes from public databases. Read More

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Nitrogenase activity, oxygen exposure, and hydrogen production by .

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Plant and Microbial Biology, North Carolina State University, Raleigh, North Carolina, USA

selectively utilizes three types of nitrogenase (molybdenum, vanadium, and iron-only) to fix N with their expression regulated by the presence or absence of different metal cofactors in its environment. Each alternative nitrogenase isoenzyme is predicted to have different electron flux requirements based off measurements, with the molybdenum nitrogenase requiring the lowest flux and the iron-only nitrogenase requiring the highest. Here, prior characterized strains, de-repressed in nitrogenase synthesis and also deficient in uptake hydrogenase, were further modified to generate new mutants lacking the ability to produce poly-β-hydroxybutyrate (PHB). Read More

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Characterization and genetic diversity of isolated from seafoods.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Hygiene of Food of Animal Origin, National Veterinary Research Institute, Pulawy, Poland.

is a widespread bacterium in marine environment responsible for gastroenteritis in humans. Food-borne infections are mainly associated with the consumption of contaminated raw or undercooked fish and shellfish. The aim of this study was to determine the antimicrobial resistance, virulence factors and genetic profiles of isolated from seafood originating from different countries. Read More

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June 2018
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Genetic diversity and co-occurrence patterns of marine cyanopodoviruses and picocyanobacteria.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China

Picocyanobacteria and are abundant in the global oceans and subjected to active viral infection. In this study, genetic diversity of picocyanobacteria and cyanopodoviruses were synchronously investigated along water columns in the equatorial Indian Ocean and over a seasonal time course in the coastal Sanya Bay, South China Sea. Using the 16S-23S rRNA ITS-based clone library and qPCR analyses, picocyanobacterial community composition and abundance were determined. Read More

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Phenotypic divergence along geographic gradients reveals potential for rapid adaptation of the White-nose Syndrome pathogen, , in North America.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Biology, McMaster University, 1280 Main St. West, Hamilton, Ontario, L8S 4K1, Canada

White-nose Syndrome (WNS) is an ongoing epizootic affecting multiple species of North American bats, caused by epidermal infections of the psychrophilic filamentous fungus, Since its introduction from Europe, WNS has spread rapidly across eastern North America and resulted in high mortality rates in bats. At present, the mechanisms behind its spread and the extent of its adaptation to different geographic and ecological niches remain unknown. The objective of this study was to examine the geographic patterns of phenotypic variation and the potential evidence for adaptation among strains representing broad geographic locations in eastern North America. Read More

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Proteome response of a metabolically flexible anoxygenic phototroph to Fe(II) oxidation.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Geomicrobiology, University of Tübingen, Germany.

The oxidation of Fe(II) by anoxygenic photosynthetic bacteria was likely a key contributor to Earth's biosphere prior to the evolution of oxygenic photosynthesis and is still found in a diverse range of modern environments. All known phototrophic Fe(II)-oxidizers can utilize a wide range of substrates thus making them very metabolically flexible. However, the underlying adaptations required to oxidize Fe(II), a potential stressor, are not completely understood. Read More

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Persistent bacterial and fungal community shifts exhibited in selenium-contaminated reclaimed mine soils.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Earth Sciences, University of Minnesota - Twin Cities, Minneapolis, MN USA

Mining and other industrial activities worldwide have resulted in Se-enriched surface soils, which pose risks to human and environmental health. Although not well studied, microbial activity can alter Se bioavailability and distribution, even in oxic environments. We used high throughput sequencing to profile bacterial and fungal communities inhabiting mine soils in southeastern Idaho, comparing mined and unmined locations within two reclaimed phosphate mine areas containing variable Se concentrations. Read More

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Inter-population variation in the Atlantic salmon microbiome reflects environmental and genetic diversity.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Swansea University, College of Science, Centre for Sustainable Aquatic Research, Swansea, SA2 8PP, UK.

The microbiome has a crucial influence on host phenotype, and is of broad interest to ecological and evolutionary research. Yet, the extent of variation that occurs in the microbiome within and between populations is unclear. We characterised the skin and gut microbiome of seven populations of juvenile Atlantic salmon () inhabiting a diverse range of environments, including hatchery-reared and wild populations. Read More

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sp. nov., etiologic agent of systemic disease in cultured spotted rose snapper () in Central America.

Appl Environ Microbiol 2018 Jun 18. Epub 2018 Jun 18.

Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA.

Historically, piscine francisellosis in various warm, temperate and coldwater fish hosts has been attributed to From 2015-2016, an undescribed sp. was recovered during mortality events in cultured spotted rose snapper () off the Pacific coast of Central America. Despite high mortality and emaciation, limited gross findings were observed in affected fish. Read More

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Poikilothermic animals as a previously unrecognized source of fecal indicator bacteria in a backwater ecosystem of a large river.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Institute of Chemical Engineering, Research Group Environmental Microbiology and Molecular Ecology, Vienna University of Technology, Vienna, Austria

Quantitative information regarding the presence of , intestinal enterococci and in poikilotherms is notably scarce. Therefore, this study was designed to allow a systematic comparison of the occurrence of these standard fecal indicator bacteria (SFIB) in the excreta of wild homeothermic (ruminants, boars, carnivores, birds) and poikilothermic animals (earthworms, gastropods, frogs, and fish) inhabiting an alluvial backwater area in eastern Austria. With the exception of earthworms, the average concentrations of and enterococci in the excreta of poikilotherms were equal to or only slightly lower than those observed in homeothermic excreta and were 1-4 orders of magnitude higher than the levels observed in the ambient soils and sediments. Read More

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Comparing the temporal process of wood metabolism among white and brown rot fungi by coupling secretomics with enzyme activities.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

University of Minnesota Department of Bioproducts and Biosystems Engineering, St. Paul, Minnesota, United States of America

Wood-degrading fungi use a sequence of oxidative and hydrolytic mechanisms to loosen lignocellulose and then release and metabolize embedded sugars. These temporal sequences have recently been mapped at high resolution using directional growth on wood wafers, revealing previously obscured dynamics as fungi progressively colonize wood. Here, we applied secretomics in the same wafer design to track temporal trends on aspen decayed by fungi with distinct nutritional modes: two brown rot-type (BR) fungi (, ) and two white rot (WR) (, ). Read More

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Hydrolase CehA and monooxygenase CfdC are responsible for the degradation of carbofuran in sp. strain CDS-1.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, PR China.

Carbofuran, a broad-spectrum systemic insecticide, has been extensively used for approximately 50 years. Diverse carbofuran-degrading bacteria have been described, among which sphingomonads have exhibited an extraordinary ability to catabolize carbofuran; other bacteria can only convert carbofuran to carbofuran phenol, while all carbofuran-degrading sphingomonads can degrade both carbofuran and carbofuran phenol. However, the genetic basis of carbofuran catabolism in sphingomonads has not been well elucidated. Read More

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MgrA negatively Regulates Biofilm Formation and Detachment by Repressing the Expression of Operons in .

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Hefei National Laboratory for Physical Sciences at Microscale, the CAS Key Laboratory of Innate Immunity and Chronic Disease, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China

Phenol-soluble modulins (PSMs) are amphipathic peptides produced by staphylococci and play important roles in biofilm formation and dissemination in Although the multiple functions of PSMs have been recognized, the regulatory mechanisms controlling the expression of operons remain largely unknown. In this study, we identified MgrA by DNA pulldown assay and further demonstrated that MgrA could specifically bind to the promoter regions of operons by electrophoretic mobility shift assay and DNase I footprinting assay. We then constructed the isogenic deletion strain, and compared biofilm formation and detachment in the wild type and the isogenic deletion strains. Read More

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Substrate-Specific Differential Gene Expression and RNA editing in the Brown Rot Fungus .

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Biology Department, Clark University, Worcester MA, USA

Wood-decaying fungi tend to have characteristic substrate ranges that partly define their ecological niche. is a brown rot species of Polyporales that is reported on 82 species of softwoods and 42 species of hardwoods. We analyzed gene expression levels and RNA editing profiles of from submerged cultures with ground wood powder (sampled at five days) or solid wood wafers (sampled at ten and thirty days), using aspen, pine, and spruce substrates (aspen was used only in submerged cultures). Read More

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Multi-Locus Variable number of tandem repeat Analysis (MLVA) of confirms the existence of host-specificity, geographic endemism and anthropogenic dissemination of virulent clones.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Norwegian Veterinary Institute, Oslo, Norway

A Multi-Locus Variable number of tandem repeat Analysis (MLVA) assay was developed for epizootiological study of the internationally significant fish pathogen , which causes yersiniosis in salmonids. The assay involves amplification of ten Variable Number of Tandem Repeat (VNTR) loci in two five-plex PCR reactions, followed by capillary electrophoresis. A collection of 484 isolates, originating from various biological sources and collected from four continents over seven decades, was analysed. Read More

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The plant growth-promoting rhizobacterium CGMCC 4969 regulates the level of indole-3-acetic acid synthesized from indole-3-acetonitrile.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Jiangsu Key Laboratory for Microbes and Functional Genomics, Jiangsu Engineering and Technology Research Center for Industrialization of Microbial Resources, College of Life Science, Nanjing Normal University, Nanjing 210023, People's Republic of China

is a metabolically diverse genus of plant growth-promoting rhizobacteria (PGPR) that engages in mutually beneficial interactions between plants and microbes. Unlike most PGPR, cannot synthesize the phytohormone indole-3-acetic acid (IAA) via tryptophan. However, we found that strain CGMCC 4969 could produce IAA using indole-3-acetonitrile (IAN) as the precursor. Read More

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Reconstruction of the bifidobacterial pan-secretome reveals the network of extracellular interactions between bifidobacteria and the infant gut.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Laboratory of Probiogenomics, Department of Chemistry, Life Sciences, and Environmental Sustainability, University of Parma, Parma, Italy

The repertoire of secreted proteins decoded by a microorganism represents proteins released from or associated with the cell's surface. In gut commensals, such as bifidobacteria, these proteins are perceived to be functionally relevant as they regulate the interaction with the gut environment. In the current study, we have screened the predicted proteome of over 300 bifidobacterial strains amongst the currently recognized bifidobacterial species to generate a comprehensive database encompassing bifidobacterial extracellular proteins. Read More

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Coevolution of both thermostability and activity of polyphosphate glucokinase from YX.

Appl Environ Microbiol 2018 Jun 8. Epub 2018 Jun 8.

Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, 32 West 7 Avenue, Tianjin Airport Economic Area, Tianjin 300308, China

Thermostability and specific activity of enzymes are two of the most important properties for industrial biocatalysts. Here we developed a Petri dish-based double-layer high-throughput screening (HTS) strategy for rapid identification of desired mutants of polyphosphate glucokinase (PPGK) from a thermophilic actinobacterium YX with both enhanced thermostability and activity. colonies representing a PPGK mutant library were grown on the first-layer Phytagel™-based plates, which can remain solid for 1 h even at heat treatment temperatures of more than 100 °C. Read More

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Isolation of toxigenic from animal manure and composts being used as biological soil amendments.

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

Department of Food, Nutrition, and Packaging Sciences, Clemson University, Clemson, South Carolina, USA

The well-known nosocomial pathogen, , has recently been recognized as a community associated pathogen. As livestock animals carry and shed in the feces, animal manure-based composts may play an important role in disseminating toxigenic into the agricultural environment. The present study surveyed contamination of commercially available composts and animal manure. Read More

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Specific phenotypic traits of regarding nitrogen source consumption and central carbon metabolites production during wine fermentation.

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

SPO, INRA, SupAgro, Université de Montpellier, F-34060 Montpellier, France

Over the last past years, the potential of non-Saccharomyces yeasts to improve the sensory quality of wine has been well recognized. In particular, the use of in mixed fermentations with was reported as an appropriate way to enhance glycerol formation and reduce ethanol production. However, during sequential fermentation, many factors as the inoculation timing, strain combination and physical and biochemical interactions can affect yeast growth, fermentation process and/or metabolite synthesis. Read More

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Quantifying the Relative Contributions of Environmental Sources to the Microbial Community in an Urban Stream under Dry and Wet Weather Conditions.

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

Department of Civil Engineering, University of Nebraska, Lincoln, Nebraska, USA

Investigating sources of microbial contamination in urban streams, especially when there are no contributions from combined sewer overflows or sewage effluent discharges, can be challenging. The objectives of this study were to identify the sources of microbes in an urban stream and quantify their relative contributions to the microbial community in the stream under dry and wet weather conditions. A microbial source tracking method relying on the 16S rRNA gene was used to investigate the microbial communities in water samples of an urban stream (i. Read More

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June 2018
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Functional determinants of extracellular polymeric substances in membrane biofouling: Experimental evidence from pure-cultured sludge bacteria.

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, PR China

The aim of this work is to better understand the roles of extracellular polymeric substances (EPS) in membrane biofouling at the single strain level. In the present study, a total of 23 bacterial strains were isolated from a sludge sample. The EPS extracted from pure-cultured bacteria were assessed for their fouling potentials and were simultaneously analyzed using Fourier-transform infrared (FTIR) spectroscopy. Read More

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June 2018
2 Reads

Engineering for glutarate production as the C5 platform backbone.

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

National Engineering Laboratory for Cereal Fermentation Technology (NELCF), Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China.

Glutarate is a linear chain dicarboxylic acid having wide applications in the production polyesters and polyamides such as nylon-4,5 and nylon-5,5. Previous studies focused on the biological production of glutarate from lysine with low yields and titers. Here, we report the glutarate production by using a five-step reverse adipate-degradation pathway (RADP) identified in By expressing the enzymes of RADP, the glutarate was detected by strain Bgl146 in shaken flasks. Read More

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Unveiling concealed functions of endosymbiotic bacteria harboured in the Ascomycota .

Appl Environ Microbiol 2018 Jun 1. Epub 2018 Jun 1.

Fundación MEDINA, Granada, Spain.

Amongst the plethora of unusual secondary metabolites isolated from are the tetrapeptidic endolides A and B. Both tetrapeptides contain 3-(3-furyl)-alanine residues, previously proposed to originate from bacterial metabolism. Inspired by this observation, we aimed to identify the presence of endosymbiotic bacteria in and to discover the true producer of the endolides. Read More

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June 2018
2 Reads

Erratum for George et al., "Interactions of Salmonella enterica Serovar Typhimurium and Pectobacterium carotovorum within a Tomato Soft Rot".

Appl Environ Microbiol 2018 Jun 31;84(12). Epub 2018 May 31.

Soil and Water Science Department, Genetics Institute, University of Florida-IFAS, Gainesville, Florida, USA.

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June 2018
1 Read

LEA proteins and the evolution of the WHy domain.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Centre For Microbial Ecology and Genomics, Department of Biochemistry, Genetics and Microbiology, University of Pretoria, Hatfield 0028, Pretoria, South Africa

The LEA family is composed of a diverse collection of multi-domain and multi-functional proteins, found in all three Domains of the Tree of Life, but particularly common in plants. Most members of the family are known to play an important role in abiotic stress response and stress tolerance in plants, but are also part of the plant hypersensitive response to pathogen infection. The mechanistic basis for LEA protein functionality is still poorly understood. Read More

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Transmission of Mono-species and Dual-species Biofilms from Smooth to Nanopillared Surfaces.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

University of Groningen and University Medical Center Groningen, Department of Biomedical Engineering, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands.

Transmission of bacteria in biofilms from donor to receiver surfaces precedes formation of biofilms in many applications. Biofilm transmission is different from bacterial adhesion, because it involves biofilm compression in between two surfaces, followed by a separation force leading to detachment of the biofilm from the donor surface and subsequent adhesion to the receiver surface. Therewith transmission depends on a balance between donor and receiver surface properties, and the cohesiveness of the biofilm itself. Read More

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May 2018
1 Read

The significance of enterotoxigenic (ETEC) heat-labile toxin (LT) enzymatic subunit epitopes in LT enterotoxicity and immunogenicity.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Department of Diagnostic Medicine/Pathobiology, Kansas State University College of Veterinary Medicine, Manhattan, KS

Enterotoxigenic (ETEC) producing heat-labile toxin (LT) and/or heat-stable toxin (STa) are a top cause of children's diarrhea and travelers' diarrhea. Holotoxin-structured GM-binding LT is a strong immunogen and an effective adjuvant, and can serve a carrier or a platform for multivalent vaccine development. However, the significance of peptide domains or epitopes of LT particularly enzymatic LT subunit in association with LT enterotoxicity and immunogenicity has not been characterized. Read More

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Filamentous giant from Guaymas Basin are capable of both denitrification and dissimilatory nitrate reduction to ammonium (DNRA).

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Max Planck Institute for Marine Microbiology, Bremen, Germany.

Filamentous large sulfur-oxidizing bacteria (FLSB) of the family are globally-distributed, aquatic bacteria that can control geochemical fluxes from the sediment to the water column through their metabolic activity. FLSB mats from hydrothermal sediments of Guaymas Basin, Mexico typically have a "fried egg" appearance, with orange filaments dominating near the center and wider white filaments at the periphery, likely reflecting areas of higher and lower sulfide fluxes, respectively. These FLSB store large quantities of intracellular nitrate that they use to oxidize sulfide. Read More

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Experimental Evolution of K-12 at High pH and RpoS Induction.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Department of Biology, Kenyon College, Gambier, Ohio, USA

Experimental evolution of K-12 W3110 by serial dilutions for 2,200 generations at high pH extended the range of sustained growth from pH 9.0 to pH 9.3. Read More

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May 2018
1 Read

Construction of a new stable, autonomously replicating plasmid vector containing centromeric DNA.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Graduate School of Science, Technology and Innovation, Kobe University, Kobe, Japan

The methylotrophic yeast is widely used to produce recombinant proteins, taking advantage of this species' high-density cell growth and strong ability to secrete proteins. Circular plasmids containing the -specific autonomously replicating sequence () permits transformation of with higher efficiency than obtained following chromosomal integration by linearized DNA. Unfortunately, however, existing autonomously replicating plasmids are known to be inherently unstable. Read More

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Involvement of β-carbonic anhydrase (β-CA) genes in bacterial genomic islands and horizontal transfer to protists.

Appl Environ Microbiol 2018 05 25. Epub 2018 May 25.

Faculty of Medicine and Life Sciences, University of Tampere, Tampere, Finland.

Genomic islands (GIs) are a type of mobile genetic element (MGE) that are present in bacterial chromosomes. They consist of a cluster of genes which produce proteins that contribute to a variety of functions, including, but not limited to, regulation of cell metabolism, anti-microbial resistance, pathogenicity, virulence, and resistance to heavy metals. The genes carried in MGEs can be used as a trait reservoir in times of adversity. Read More

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May 2018
4 Reads

Agmatine Production by is Elevated by Low pH During Solid-State Cultivation.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Department of Bioscience, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda, Hyogo, Japan

Sake (rice wine) produced by multiple parallel fermentation (MPF) involving (strain RW) and under solid-state cultivation conditions contained 3.5 mM agmatine, while that produced from enzymatically saccharified rice syrup by contained <0.01 mM agmatine. Read More

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has characteristics of a keystone species in bifidobacterial blooms in the ceca of rats fed Hi-Maize starch.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Department of Microbiology and Immunology, and Microbiome Otago, University of Otago, Dunedin, New Zealand

Starches resistant to mammalian digestion are present in foods and pass to the large bowel where they may be degraded and fermented by the microbiota. Increases in relative abundances of bifidobacteria (blooms) have been reported in rats whose diet was supplemented with Hi-Maize resistant starch. We determined that the bifidobacterial species present in the rat cecum under these circumstances mostly belonged to However, cultures of isolated from the rats failed to degrade Hi-Maize starch to any extent. Read More

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May 2018
3 Reads

Heterologous expression of alkene monooxygenases from in Gram positive and Gram negative bacterial hosts.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

School of Life and Environmental Sciences, Building G08, Maze Crescent, University of Sydney, NSW, 2006, Australia

Alkene monooxygenases (MOs) are soluble di-iron-containing enzymes found in bacteria that grow on alkenes. Here we report improved heterologous expression systems for the propene MO (PmoABCD) and ethene MO (EtnABCD) from strain NBB4. Strong functional expression of PmoABCD and EtnABCD was achieved in mc-155, yielding epoxidation activites (62 and 27 nmol/min/mg protein, respectively) higher than any reported to date for heterologous expression of a di-iron MO system. Read More

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May 2018
1 Read

Short-term transcriptional response of microbial communities to N-fertilization in a pine forest soil.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Bioscience Division, Los Alamos National Laboratory, Los Alamos, NM.

Numerous studies have examined the long-term effect of experimental nitrogen (N) deposition in terrestrial ecosystems, however N-specific mechanistic markers are difficult to disentangle from responses to other environmental changes. The strongest picture of N-responsive mechanistic markers is likely to arise from measurements over a short (hours to days) timescale immediately after inorganic N deposition. Therefore, we assessed the short-term (3-day) transcriptional response of microbial communities in two soil strata from a pine forest to a high dose of N fertilization (c. Read More

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The β-glucanosyltransferase contributes to fungal adaptation to extreme alkaline pH.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida 32611, USA

Fungal β-1,3-glucanosyltransferases are cell wall remodeling enzymes implicated in stress response, cell wall integrity, and virulence, with most fungal genomes containing multiple members. The insect pathogenic fungus displays robust growth over a wide pH range (pH = 4-10). Random insertion mutant library screening for increased sensitivity to alkaline (pH 10) growth conditions resulted in the identification and mapping of a mutant to a β-1,3-glucanosyltransferase gene (). Read More

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Manganese is essential for PlcP metallophosphoesterase activity involved in lipid remodelling in abundant marine heterotrophic bacteria.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom

In vast areas of the ocean, microbes must adapt to the availability of scarce nutrients and a key strategy for reducing the cellular phosphorus (P) quota is to remodel membranes by replacing phospholipids with non-P surrogate lipids. A metallophosphoesterase, PlcP, is essential for lipid remodelling in cosmopolitan marine bacteria of the (e.g. Read More

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Genetic and Biochemical Characterization of 5-Hydroxypicolinic Acid Metabolism in JQ135.

Appl Environ Microbiol 2018 May 25. Epub 2018 May 25.

Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, 210095, China

5-Hydroxypicolinic acid (5HPA), a natural pyridine derivative, is microbially degraded in the environment. However, the physiological, biochemical, and genetic foundations of the 5HPA metabolism remain unknown. In this study, an operon (), responsible for 5HPA degradation, was cloned from JQ135. Read More

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May 2018
2 Reads

MED3 affects cell size and budding index to coordinate cell growth.

Appl Environ Microbiol 2018 May 18. Epub 2018 May 18.

State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi 214122, China

is a promising microorganism for the production of organic acids. Here, we report deletion and quantitative expression approaches to elucidate the role of Med3AB, a subunit of the mediator transcriptional co-activator, in regulating cell growth. Deletion of Med3AB caused an 8. Read More

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Shuffling the neutral drift of unspecific peroxygenase in .

Appl Environ Microbiol 2018 May 18. Epub 2018 May 18.

Department of Biocatalysis, Institute of Catalysis, CSIC, 28049 Madrid, Spain.

Unspecific peroxygenase (UPO) is a highly promiscuous biocatalyst and its selective mono(per)oxygenase activity makes it useful for many synthetic chemistry applications. Among the broad repertory of library creation methods for directed enzyme evolution, genetic drift allows neutral mutations to be accumulated gradually within a polymorphic network of variants. In this study, we conducted a campaign of genetic drift with UPO in so that neutral mutations were simply added and recombined With low mutational loading and an activity threshold of 45% of the parent's native function, mutant libraries enriched in folded and active UPO variants were generated. Read More

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Modifying the lantibiotic mutacin 1140 for increased yield, activity and stability.

Appl Environ Microbiol 2018 May 18. Epub 2018 May 18.

Department of Biology, College of Science, Texas A&M University, College Station, Texas, USA

Mutacin 1140 belongs to the epidermin family of type AI lantibiotics. This family has a broad spectrum of activity against Gram-positive bacteria. The binding of mutacin 1140 to lipid II leads to the inhibition of cell wall synthesis. Read More

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May 2018
1 Read

Antibacterial effects of phage lysin LysGH15 on planktonic cells and biofilms of diverse staphylococci.

Appl Environ Microbiol 2018 May 18. Epub 2018 May 18.

Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun 130062, China.

Treatment of infections caused by staphylococci has become more difficult because of the emergence of multidrug-resistant strains as well as biofilm formation. In this study, we observed the ability of the phage lysin LysGH15 to eliminate staphylococcal planktonic cells and biofilms formed by and All these strains were sensitive to LysGH15, showing reductions in bacterial counts of approximately 4 log units within 30 min after treatment with 20 μg/mL LysGH15, and the minimum inhibitory concentrations (MICs) ranged from 8 μg/mL to 32 μg/mL. LysGH15 efficiently prevented biofilm formation by the four staphylococcal species at a dose of 50 μg/mL. Read More

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