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Applied and Environmental Microbiology

Kouhei Kishida, Kei Inoue, Yoshiyuki Ohtsubo, Yuji Nagata, Masataka Tsuda
: NAH7 and pWW0 from γ-proteobacterial Pseudomonas putida strains are IncP-9 conjugative plasmids that carry the genes for degradation of naphthalene and toluene, respectively. Although such genes on these plasmids are well-characterized, experimental investigation of their conjugation systems remains at a primitive level. To clarify these conjugation systems, in this study we investigated the NAH7-encoded conjugation system by (i) analyzing the origin of its conjugative transfer (oriT)-containing region and its relaxase, which specifically nicks within the oriT region for initiation of transfer, and by (ii) comparing the conjugation systems between NAH7 and pWW0...
October 14, 2016: Applied and Environmental Microbiology
Indira T Kudva, Michelle Q Carter, Vijay K Sharma, Judith A Stasko, Jorge A Giron
: Our recent studies have shown that Intimin and the Locus of Enterocyte Effacement-encoded proteins do not play a role in Escherichia coli O157:H7 (O157) adherence to the bovine recto-anal junction squamous epithelial (RSE) cells. To define factors that play a contributory role, we investigated the role of curli, a fimbrial adhesin commonly implicated in adherence to various fomites, plant, and human epithelial cells, in O157 adherence to RSE cells. Specifically, we examined (i) wild-type strains of O157; (ii) curli variants of O157 strains; (iii) isogenic curli-deletion mutants of O157; and (iv) adherence-inhibition of O157 using anti-curlin sera...
October 14, 2016: Applied and Environmental Microbiology
Yun-Feng Duan, Xian-Wang Kong, Andreas Schramm, Rodrigo Labouriau, Jørgen Eriksen, Søren O Petersen
: Grassland cultivation can mobilize large pools of N in the soil, with a potential for N leaching and N2O emissions. Spraying with the nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) before cultivation was simulated with soil columns where residue distribution corresponded to ploughing or rotovation, to study effects of soil-residue contact on N transformations. DMPP was sprayed on above-ground parts of ryegrass and white clover before incorporation. During a 42-day incubation, soil mineral N dynamics, potential ammonia oxidation (PAO) and denitrifying enzyme activity (DEA), nitrifier and denitrifier populations, and N2O emissions were investigated...
October 14, 2016: Applied and Environmental Microbiology
Sen Wang, Dong Zhao, Xinfeng Bai, Weican Zhang, Xuemei Lu
: Cytophaga hutchinsonii is a gram-negative bacterium which can efficiently degrade crystalline cellulose by a unique mechanism different from free cellulases or cellulosomes strategy. In this study, chu_3220, encoding a hypothetical protein CHU_3220 (205 kDa), was identified by insertional mutation and gene deletion to be the first gene essential for degradation of crystalline region but not amorphous region of cellulose by C. hutchinsonii chu_3220-deletion mutant was defective in degradation of crystalline cellulose and increased the degree of crystallinity of Avicel PH101, but could still degrade amorphous cellulose completely...
October 14, 2016: Applied and Environmental Microbiology
Franziska Szokoli, Michele Castelli, Elena Sabaneyeva, Martina Schrallhammer, Sascha Krenek, Thomas G Doak, Thomas U Berendonk, Giulio Petroni
In the past ten years, the number of endosymbionts described within the bacterial order Rickettsiales has constantly grown. Since 2006, 18 novel Rickettsiales genera inhabiting protists, such as ciliates and amoebae, have been described. In this work, we characterize two novel bacterial endosymbionts from Paramecium collected near Bloomington, Indiana (USA). Both endosymbiotic species inhabit the cytoplasm of the same host. The Gram-negative bacterium "Candidatus Bealeia paramacronuclearis" occurs in clumps and is frequently associated with the host macronucleus...
October 14, 2016: Applied and Environmental Microbiology
Natalie C Sadler, Hans C Bernstein, Matthew R Melnicki, Moiz A Charania, Eric A Hill, Lindsey N Anderson, Matthew E Monroe, Richard D Smith, Alexander S Beliaev, Aaron T Wright
: Photobiologically synthesized hydrogen (H2) gas is carbon-neutral to produce and clean to combust, making it an ideal biofuel. Cyanothece sp. ATCC 51142 is a cyanobacterium capable of performing simultaneous oxygenic photosynthesis and H2 production, a highly perplexing phenomenon because H2 evolving enzymes are O2-sensitive. We employed a systems-level in vivo chemoproteomic profiling approach to explore the cellular dynamics of protein thiol redox, and how thiol redox mediates the function of the dinitrogenase NifHDK, an enzyme complex capable of aerobic hydrogenase activity...
October 14, 2016: Applied and Environmental Microbiology
D Lee Taylor, William A Walters, Niall J Lennon, James Bochicchio, Andrew Krohn, J Gregory Caporaso, Taina Pennanen
: While high-throughput-sequencing methods are revolutionizing fungal ecology, recovering accurate estimates of species richness and abundance has proven elusive. We sought to design ITS primers and an Illumina protocol that would maximize coverage of the kingdom Fungi while minimizing non-target eukaryotes. We inspected alignments of the 5.8S and LSU ribosomal genes and evaluated potential primers using PrimerProspector. We tested the resulting primers using tiered-abundance mock communities and five previously characterized soil samples...
October 7, 2016: Applied and Environmental Microbiology
Elisa Schiavi, Marita Gleinser, Evelyn Molloy, David Groeger, Remo Frei, Ruth Ferstl, Noelia Rodriguez-Perez, Mario Ziegler, Ray Grant, Thomas Fintan Moriarty, Stephan Plattner, Selena Healy, Mary O'Connell Motherway, Cezmi A Akdis, Jennifer Roper, Friedrich Altmann, Douwe van Sinderen, Liam O'Mahony
: The immune modulating properties of certain bifidobacterial strains, such as Bifidobacterium longum subsp. longum 35624: ™ (B. longum 35624), have been well described, although the strain-specific molecular characteristics associated with such immune regulatory activity are not well defined. It has previously been demonstrated that B. longum 35624: produces a cell surface exopolysaccharide and in this study we investigated the role played by this exopolysaccharide in influencing the host immune response...
October 7, 2016: Applied and Environmental Microbiology
Jilong Wang, Suthamat Niyompanich, Yi-Shu Tai, Jingyu Wang, Wenqin Bai, Prithviraj Mahida, Tuo Gao, Kechun Zhang
: Chromosomal integration of heterologous metabolic pathways is optimal for industrially relevant fermentation, as plasmid-based fermentation causes extra metabolic burden and genetic instabilities. In this work, chromosomal integration was adapted for the production of mevalonate which can be readily converted into β-methyl-δ-valerolactone, a monomer for the production of mechanically tunable polyesters. The mevalonate pathway driven by a constitutive promoter was integrated into the chromosome of Escherichia coli to replace the native fermentation gene adhE or ldhA The engineered strains (CMEV-1 and CMEV-2) did not require inducer or antibiotic, and showed slightly higher maximal productivities (0...
October 7, 2016: Applied and Environmental Microbiology
Getahun E Agga, John W Schmidt, Terrance M Arthur
: Concerns have been raised that in-feed chlortetracycline (CTC) may increase antimicrobial resistance (AMR), specifically tetracycline-resistant (TET(r)) Escherichia coli, and third-generation cephalosporin-resistant (3GC(r)) E. coli We evaluated the impact of a 5-day in-feed CTC prophylaxis on animal health, TET(r) E. coli, and 3GC(r) E. coli A "control group" of cattle (n = 150) received no CTC, while a "CTC group" (n = 150) received in-feed CTC (10 mg/lb of body weight/day) from the 5th to the 9th day after feedlot arrival...
October 7, 2016: Applied and Environmental Microbiology
Qiang Zheng, Yanting Liu, Christian Jeanthon, Rui Zhang, Wenxin Lin, Jicheng Yao, Nianzhi Jiao
: Aerobic anoxygenic phototrophic bacteria (AAPB) are thought to be important players in oceanic carbon and energy cycling in the euphotic zone of the ocean. The genus Citromicrobium, widely found in oligotrophic oceans, is a member of marine alphaproteobacterial AAPB. Nine Citromicrobium strains isolated from the South China Sea, the Mediterranean Sea or the tropical South Atlantic were found to harbor identical 16S rRNA sequences. The sequencing of their genomes revealed high synteny in major regions...
October 7, 2016: Applied and Environmental Microbiology
Allison M Weis, Dylan B Storey, Conor C Taff, Andrea K Townsend, Bihua C Huang, Nguyet T Kong, Kristin A Clothier, Abigail Spinner, Barbara A Byrne, Bart C Weimer
: Campylobacter is the leading cause of human gastroenteritis worldwide. Wild birds, including American crows are abundant in urban, suburban, and agricultural settings, and are likely zoonotic vectors of Campylobacter. Their proximity to humans and livestock increases the potential spreading of Campylobacter via crows between the environment, livestock, and humans. However, no studies have definitively demonstrated that crows are a vector for pathogenic Campylobacter We used genomics to evaluate zoonotic and pathogenic potential of Campylobacter from crows to other animals with 184 isolates obtained from crow, chicken, cow, sheep, goat, human, and non-human primates...
October 7, 2016: Applied and Environmental Microbiology
Jaime Aguayo, Fabien Halkett, Claude Husson, Zoltán Á Nagy, András Szigethy, József Bakonyi, Pascal Frey, Benoit Marçais
: Assessing the process that gives rise to hybrid pathogens is central to understand the evolution of emerging plant diseases. Phytophthora ×alni, a pathogen of alder, results from the homoploid hybridization of two related species, Phytophthora uniformis and Phytophthora ×multiformis Describing genetic characteristics of P. ×alni should help understanding how reproductive mechanisms and historical processes shaped the population structure of this emerging hybrid pathogen. The population genetic structure of P...
October 7, 2016: Applied and Environmental Microbiology
Luiz Ricardo Gonçalves, Alexsandra Rodrigues de Mendonça Favacho, André Luiz Rodrigues Roque, Natalia Serra Mendes, Otávio Luiz Fidelis Junior, Jyan Lucas Benevenute, Heitor Miraglia Herrera, Paulo Sérgio D'Andrea, Elba Regina Sampaio de Lemos, Rosangela Zacarias Machado, Marcos Rogério André
: Bartonella spp. comprise an ecologically successful group of microorganisms that infects erythrocytes and have adapted to different hosts, which include a wide range of mammals, besides humans. Rodents are reservoirs of about two thirds of Bartonella spp. described to date; and some of them have been implicated as causative agents of human diseases. In our study, we performed the molecular and phylogenetic analyses of Bartonella spp. infecting wild rodents from five different Brazilian biomes...
October 7, 2016: Applied and Environmental Microbiology
Marcel Suleiman, Karsten Zecher, Onur Yücel, Nina Jagmann, Bodo Philipp
: Methylamines occur ubiquitously in the oceans and can serve as carbon, nitrogen and energy source for heterotrophic bacteria from different phylogenetic groups within the marine bacterioplankton. Diatoms, which constitute a large part of the marine phytoplankton, are believed to be incapable of using methylamines as nitrogen source. As diatoms are typically associated with heterotrophic bacteria, the hypothesis came up that methylotrophic bacteria may provide ammonium to diatoms by degradation of methylamines...
September 30, 2016: Applied and Environmental Microbiology
Xiaotong Qiu, Xuemei Bai, Ruiting Lan, Han Zheng, Jianguo Xu
: Streptococcus suis is an important pathogen of pigs and may cause serious disease in humans. Serotyping is an important tool in diagnosis and epidemiological studies of S. suis. Thirty-three reference serotypes and 9 novel cps loci (NCL) are recognized in S. suis To gain a better understanding of the prevalence and genetic characteristics of NCLs, we investigated the serotype identity of 486 isolates isolated between 2013 and 2015 in China by capsular gene typing methods. Two hundred and seventy six isolates carried NCL belonging to 16 groups, 8 of which were first reported in this study...
September 30, 2016: Applied and Environmental Microbiology
Peter Biely
A carbohydrate esterase, called glucuronoyl esterase (GE), was discovered ten year ago in a cellulolytic system of the wood-rotting fungus Schizophyllum commune Genes coding for GEs were subsequently found in a number of microbial genomes and a new family of carbohydrate esterases (CE15) has been established. The multidomain structures of GEs together with their catalytic properties on artificial substrates and positive effect on enzymatic saccharification of plant biomass leads to the view that the esterases evolved for hydrolysis of the ester linkages between 4-O-methyl-D-glucuronic acid of plant glucuronoxylans and lignin alcohols, one of the cross-links in the plant cell walls...
September 30, 2016: Applied and Environmental Microbiology
Eric Robert Lucien Gordon, Quinn McFrederick, Christiane Weirauch
: The insect order Hemiptera, one of the best-studied insect lineages with respect to bacterial symbioses, still contains major branches which lack comprehensive characterization of associated bacterial symbionts. The Pyrrhocoroidea (Largidae [220 species]; Pyrrhocoridae [∼300 species]) is a clade of the hemipteran infraorder Pentatomomorpha. Studies on bacterial symbionts of this group have focused on members of Pyrrhocoridae, but recent examination of species of two genera of Largidae demonstrated divergent symbiotic complexes between these putative sister families...
September 30, 2016: Applied and Environmental Microbiology
Liang Tian, Jonathan Lo, Xiongjun Shao, Tianyong Zheng, Daniel G Olson, Lee R Lynd
: Ferredoxin:NAD(+) oxidoreductase (NADH-FNOR) catalyzes the transfer of electrons from reduced ferredoxin to NAD(+) This enzyme has been hypothesized to be the main enzyme responsible for ferredoxin oxidization in the NADH-based ethanol pathway in Thermoanaerobacterium saccharolyticum, however, the corresponding gene has not yet been identified. Here, we identified the Tsac_1705 protein as a candidate FNOR based on the homology of its functional domains. We then confirmed its activity in vitro with a ferredoxin-based FNOR assay...
September 30, 2016: Applied and Environmental Microbiology
Viriya Hantrakun, Patpong Rongkard, Malinee Oyuchua, Premjit Amornchai, Cherry Lim, Vanaporn Wuthiekanun, Nicholas Pj Day, Sharon J Peacock, Direk Limmathurotsakul
: Burkholderia pseudomallei is a soil-dwelling bacterium and the cause of melioidosis, which kills an estimated 89,000 people per year worldwide. Agricultural workers are at high risk of infection due to repeated exposure. Little is known about soil physicochemical properties associated with presence or absence of the organism. Here, we evaluated the soil physicochemical properties and presence of B. pseudomallei in 6,100 soil samples collected from 61 rice fields in Thailand. The presence of B...
September 30, 2016: Applied and Environmental Microbiology
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