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https://www.readbyqxmd.com/read/27909745/dechlorination-of-three-tetrachlorobenzene-isomers-by-contaminated-harbor-sludge-derived-enrichment-cultures-follows-thermodynamically-favorable-reactions
#1
Yue Lu, Javier Ramiro-Garcia, Pieter Vandermeeren, Steffi Herrmann, Danuta Cichocka, Dirk Springael, Siavash Atashgahi, Hauke Smidt
Dechlorination patterns of three tetrachlorobenzene isomers, 1,2,3,4-, 1,2,3,5-, and 1,2,4,5-TeCB, were studied in anoxic microcosms derived from contaminated harbor sludge. The removal of doubly, singly, and un-flanked chlorine atoms was noted in 1,2,3,4- and 1,2,3,5-TeCB fed microcosms, whereas only singly flanked chlorine was removed in 1,2,4,5-TeCB microcosms. The thermodynamically more favorable reactions were selectively followed by the enriched cultures with di- and/or mono-chlorobenzene as the main end products of the reductive dechlorination of all three isomers...
December 1, 2016: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/27902965/oxygen-transfer-dynamics-and-activated-sludge-floc-structure-under-different-sludge-retention-times-at-low-dissolved-oxygen-concentrations
#2
Haitao Fan, Xiuhong Liu, Hao Wang, Yunping Han, Lu Qi, Hongchen Wang
In activated sludge systems, the aeration process consumes the most energy. The energy cost can be dramatically reduced by decreasing the operating dissolved oxygen (DO) concentration. However, low DO may lead to incomplete nitrification and poor settling performance of activated sludge flocs (ASFs). This study investigates oxygen transfer dynamics and settling performances of activated sludge under different sludge retention times (SRTs) and DO conditions using microelectrodes and microscopic techniques. Our experimental results showed that with longer SRTs, treatment capacity and settling performances of activated sludge improved due to smaller floc size and less extracellular polymeric substances (EPS)...
November 27, 2016: Chemosphere
https://www.readbyqxmd.com/read/27902881/the-chimeric-nature-of-the-genomes-of-marine-magnetotactic-coccoid-ovoid-bacteria-defines-a-novel-group-of-proteobacteria
#3
Boyang Ji, Sheng-Da Zhang, Wei-Jia Zhang, Zoe Rouy, François Alberto, Claire-Lise Santini, Sophie Mangenot, Séverine Gagnot, Nadège Philippe, Nathalie Pradel, Lichen Zhang, Sébastien Tempel, Ying Li, Claudine Médigue, Bernard Henrissat, Pedro M Coutinho, Valérie Barbe, Emmanuel Talla, Long-Fei Wu
Magnetotactic bacteria (MTB) are a group of phylogenetically and physiologically diverse Gram-negative bacteria that synthesize intracellular magnetic crystals named magnetosomes. MTB are affiliated with three classes of Proteobacteria phylum, Nitrospirae phylum, Omnitrophica phylum and probably with the candidate phylum Latescibacteria. The evolutionary origin and physiological diversity of MTB compared to other bacterial taxonomic groups remain to be illustrated. Here, we analyzed the genome of the marine magneto-ovoid strain MO-1 and found that it is closely related to Magnetococcus marinus MC-1...
November 30, 2016: Environmental Microbiology
https://www.readbyqxmd.com/read/27901306/plants-microorganisms-and-soil-temperatures-contribute-to-a-decrease-in-methane-fluxes-on-a-drained-arctic-floodplain
#4
Min Jung Kwon, Felix Beulig, Iulia Ilie, Marcus Wildner, Kirsten Küsel, Lutz Merbold, Miguel D Mahecha, Nikita Zimov, Sergey A Zimov, Martin Heimann, Edward A G Schuur, Joel E Kostka, Olaf Kolle, Ines Hilke, Mathias Göckede
As surface temperatures are expected to rise in the future, ice-rich permafrost may thaw, altering soil topography and hydrology and creating a mosaic of wet and dry soil surfaces in the Arctic. Arctic wetlands are large sources of CH4 , and investigating effects of soil hydrology on CH4 fluxes is of great importance for predicting ecosystem feedback in response to climate change. In this study, we investigate how a decade-long drying manipulation on an Arctic floodplain influences CH4 -associated microorganisms, soil thermal regimes, and plant communities...
November 7, 2016: Global Change Biology
https://www.readbyqxmd.com/read/27894799/a-microcosm-experiment-to-determine-the-consequences-of-magnetic-microparticles-application-on-water-quality-and-sediment-phosphorus-pools
#5
A Funes, A Del Arco, I Álvarez-Manzaneda, J de Vicente, I de Vicente
This study used microcosms to evaluate the effects of adding iron (Fe) magnetic microparticles (MPs) on water quality, focusing on P concentrations in the water column and sediment. Two treatments were considered for a constant 85:1 MP:PMobile molar ratio: T-W, applying MPs on the surface water layer; and T-S, applying MPs on the sediment. MP addition reduced P concentrations in lake water and sediment, with both treatments producing a mean reduction of 68±6% in dissolved inorganic P concentration (DIP) over a 70-day oxic period and reductions of 80±8% (T-W) and 80±4% (T-S) over a 5-day anoxic period...
November 25, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27891115/methanotrophy-under-versatile-conditions-in-the-water-column-of-the-ferruginous-meromictic-lake-la-cruz-spain
#6
Kirsten Oswald, Corinne Jegge, Jana Tischer, Jasmine Berg, Andreas Brand, María R Miracle, Xavier Soria, Eduardo Vicente, Moritz F Lehmann, Jakob Zopfi, Carsten J Schubert
Lakes represent a considerable natural source of methane to the atmosphere compared to their small global surface area. Methanotrophs in sediments and in the water column largely control methane fluxes from these systems, yet the diversity, electron accepting capacity, and nutrient requirements of these microorganisms have only been partially identified. Here, we investigated the role of electron acceptors alternative to oxygen and sulfate in microbial methane oxidation at the oxycline and in anoxic waters of the ferruginous meromictic Lake La Cruz, Spain...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27891050/evaluating-the-effect-of-oxygen-concentrations-on-antibiotic-sensitivity-growth-and-biofilm-formation-of-human-pathogens
#7
Shilpi Gupta, Nozrin Laskar, Daniel E Kadouri
Standard antimicrobial susceptibility tests are performed in vitro under normal room oxygen conditions to predict the in vivo effectiveness of antimicrobial therapy. The aim of this study was to conduct a comprehensive analysis of the effect of different oxygen levels on the antibiotic susceptibility of two strains of Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae. It was found that anoxic conditions caused reduced sensitivity of bacteria to aminoglycoside antibiotics in four of six bacteria used in the study...
2016: Microbiology Insights
https://www.readbyqxmd.com/read/27887813/migration-of-75-se-iv-in-crushed-beishan-granite-effects-of-the-iron-content
#8
Jiangang He, Bin Ma, Mingliang Kang, Chunli Wang, Zhe Nie, Chunli Liu
The diffusion of selenite (labeled with (75)Se) in compacted Beishan granite (BsG) was investigated using the in-diffusion capillary method at pH values from ∼2.0 to ∼11.0 under oxic and anoxic conditions. The results indicate that the apparent diffusion coefficient (Da) values of selenite in BsG always reached the minimum at approximately pH 5. Unexpectedly, the Da values under oxic conditions are nearly one order of magnitude lower than those under the anoxic conditions. Further characterization reveals the existence of redox-sensitive Fe(II)-containing components, which can be responsible for the great difference in Da values...
November 9, 2016: Journal of Hazardous Materials
https://www.readbyqxmd.com/read/27886586/nitrous-oxide-from-moving-bed-based-integrated-fixed-film-activated-sludge-membrane-bioreactors
#9
Giorgio Mannina, Marco Capodici, Alida Cosenza, Daniele Di Trapani, Vito Armando Laudicina, Hallvard Ødegaard
The present paper reports the results of a nitrous oxide (N2O) production investigation in a moving bed based integrated fixed film activated sludge (IFAS) membrane bioreactor (MBR) pilot plant designed in accordance with the University of Cape Town layout for biological phosphorous removal. Gaseous and liquid samples were collected in order to measure the gaseous as well as the dissolved concentration of N2O. Furthermore, the gas flow rate from each reactor was measured and the gas flux was estimated. The results confirmed that the anoxic reactor represents the main source of nitrous oxide production...
November 22, 2016: Journal of Environmental Management
https://www.readbyqxmd.com/read/27877167/polycyclic-aromatic-hydrocarbon-induced-changes-in-bacterial-community-structure-under-anoxic-nitrate-reducing-conditions
#10
Sophie-Marie Martirani-Von Abercron, Daniel Pacheco, Patricia Benito-Santano, Patricia Marín, Silvia Marqués
Although bacterial anaerobic degradation of mono-aromatic compounds has been characterized in depth, the degradation of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene has only started to be understood in sulfate reducing bacteria, and little is known about the anaerobic degradation of PAHs in nitrate reducing bacteria. Starting from a series of environments which had suffered different degrees of hydrocarbon pollution, we used most probable number (MPN) enumeration to detect and quantify the presence of bacterial communities able to degrade several PAHs using nitrate as electron acceptor...
2016: Frontiers in Microbiology
https://www.readbyqxmd.com/read/27872862/oxygenation-of-the-intraportally-transplanted-pancreatic-islet
#11
Thomas M Suszynski, Efstathios S Avgoustiniatos, Klearchos K Papas
Intraportal islet transplantation (IT) is not widely utilized as a treatment for type 1 diabetes. Oxygenation of the intraportally transplanted islet has not been studied extensively. We present a diffusion-reaction model that predicts the presence of an anoxic core and a larger partly functional core within intraportally transplanted islets. Four variables were studied: islet diameter, islet fractional viability, external oxygen partial pressure (P) (in surrounding portal blood), and presence or absence of a thrombus on the islet surface...
2016: Journal of Diabetes Research
https://www.readbyqxmd.com/read/27872214/effects-of-prolonged-anoxia-on-electrical-activity-of-the-heart-in-crucian-carp-carassius-carassius
#12
Elisa Tikkanen, Jaakko Haverinen, Stuart Egginton, Minna Hassinen, Matti Vornanen
The effects of sustained anoxia on cardiac electrical excitability were examined in the anoxia-tolerant Crucian carp (Carassius carassius). The electrocardiogram (ECG) and expression of excitation-contraction coupling genes were studied in fish acclimatised to normoxia in summer (+18°C) or winter (+2°C), and in winter fish after 1, 3 and 6 weeks of anoxia. Anoxia induced a sustained bradycardia from a heart rate of 10.3±0.77 to 4.1±0.29 bpm (P<0.05) after 5 weeks, and heart rate slowly recovered to control levels when oxygen was restored...
November 21, 2016: Journal of Experimental Biology
https://www.readbyqxmd.com/read/27871231/transcriptomic-and-proteomic-insights-into-innate-immunity-and-adaptations-to-a-symbiotic-lifestyle-in-the-gutless-marine-worm-olavius-algarvensis
#13
Juliane Wippler, Manuel Kleiner, Christian Lott, Alexander Gruhl, Paul E Abraham, Richard J Giannone, Jacque C Young, Robert L Hettich, Nicole Dubilier
BACKGROUND: The gutless marine worm Olavius algarvensis has a completely reduced digestive and excretory system, and lives in an obligate nutritional symbiosis with bacterial symbionts. While considerable knowledge has been gained of the symbionts, the host has remained largely unstudied. Here, we generated transcriptomes and proteomes of O. algarvensis to better understand how this annelid worm gains nutrition from its symbionts, how it adapted physiologically to a symbiotic lifestyle, and how its innate immune system recognizes and responds to its symbiotic microbiota...
November 21, 2016: BMC Genomics
https://www.readbyqxmd.com/read/27871050/removal-characteristics-of-don-in-pharmaceutical-wastewater-and-its-influence-on-the-n-nitrosodimethylamine-formation-potential-and-acute-toxicity-of-dom
#14
Haidong Hu, Cong Jiang, Haijun Ma, Lili Ding, Jinju Geng, Ke Xu, Hui Huang, Hongqiang Ren
Previous research has focused on dissolved organic carbon (DOC) as a surrogate for dissolved organic matter (DOM) in pharmaceutical wastewater. Dissolved organic nitrogen (DON) as a part of DOM has received little attention. This study investigated the removal characteristics of DON and its influence on the N-nitrosodimethylamine formation potential (NDMA FP) and acute toxicity of DOM in a full-scale hydrolysis/acidification + anaerobic/anoxic/aerobic + moving bed biofilm reactor (MBBR) process treating pharmaceutical wastewater...
October 5, 2016: Water Research
https://www.readbyqxmd.com/read/27866737/enhanced-nitrogen-loss-from-rivers-through-coupled-nitrification-denitrification-caused-by-suspended-sediment
#15
Xinghui Xia, Ting Liu, Zhifeng Yang, Greg Michalski, Shaoda Liu, Zhimei Jia, Sibo Zhang
Present-day estimations of global nitrogen loss (N-loss) are underestimated. Commonly, N-loss from rivers is thought to be caused by denitrification only in bed-sediments. However, coupled nitrification-denitrification occurring in overlying water with suspended sediments (SPS) where oxic and anoxic/low oxygen zones may coexist is ignored for N-loss in rivers. Here the Yellow and Yangtze Rivers were taken as examples to investigate the effect of SPS, which exists in many rivers of the world, on N loss through coupled nitrification-denitrification with nitrogen stable ((15)N) isotopic tracer simulation experiments and in-situ investigation...
November 17, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27865789/anoxia-ameliorates-the-dexamethasone-induced-neurobehavioral-alterations-in-the-neonatal-male-rat-pups
#16
Petr N Menshanov, Anita V Bannova, Nikolay N Dygalo
Glucocorticoids and hypoxia are two essential factors affecting the brain development during labor and delivery. In addition to the neurobehavioral alterations induced separately by these factors, glucocorticoids can attenuate the deleterious consequences of severe hypoxia-ischemia on the brain development, acting as a neuroprotective agent in combination with hypoxia. The role of hypoxia in the combined action with corticosteroids is less clear. Severe hypoxia-ischemia results in the massive activation of caspase-3, masking any other effects of hypoxia on the neonatal brain exposed to glucocorticoids...
November 16, 2016: Hormones and Behavior
https://www.readbyqxmd.com/read/27865729/improving-the-efficiency-of-dissolved-oxygen-control-using-an-on-line-control-system-based-on-a-genetic-algorithm-evolving-fwnn-software-sensor
#17
Jujun Ruan, Chao Zhang, Ya Li, Peiyi Li, Zaizhi Yang, Xiaohong Chen, Mingzhi Huang, Tao Zhang
This work proposes an on-line hybrid intelligent control system based on a genetic algorithm (GA) evolving fuzzy wavelet neural network software sensor to control dissolved oxygen (DO) in an anaerobic/anoxic/oxic process for treating papermaking wastewater. With the self-learning and memory abilities of neural network, handling the uncertainty capacity of fuzzy logic, analyzing local detail superiority of wavelet transform and global search of GA, this proposed control system can extract the dynamic behavior and complex interrelationships between various operation variables...
November 16, 2016: Journal of Environmental Management
https://www.readbyqxmd.com/read/27862807/microbial-processes-of-the-carbon-and-sulfur-cycles-in-an-ice-covered-iron-rich-meromictic-lake-svetloe-arkhangelsk-region-russia
#18
Alexander S Savvichev, Natalia M Kokryatskaya, Svetlana A Zabelina, Igor I Rusanov, Elena E Zakharova, Elena F Veslopolova, Olga N Lunina, Ekaterina O Patutina, Boris K Bumazhkin, Denis S Gruzdev, Pavel A Sigalevich, Nikolay V Pimenov, Boris B Kuznetsov, Vladimir M Gorlenko
Biogeochemical, isotope geochemical, and microbiological investigation of Lake Svetloe (White Sea basin), a meromictic freshwater was carried out in April 2014, when ice thickness was ∼0.5 m, and the ice-covered water column contained oxygen to 23-m depth. Below, the anoxic water column contained ferrous iron (up to 240 µM), manganese (60 µM), sulfide (up to 2 µM), and dissolved methane (960 µM). The highest abundance of microbial cells revealed by epifluorescence microscopy was found in the chemocline (redox zone) at 23-24...
November 16, 2016: Environmental Microbiology
https://www.readbyqxmd.com/read/27861548/targeting-mitochondrial-dysfunction-with-l-alpha-glycerylphosphorylcholine
#19
Gerda Strifler, Eszter Tuboly, Anikó Görbe, Mihály Boros, Daniella Pécz, Petra Hartmann
BACKGROUND: We hypothesized that L-alpha-glycerylphosphorylcholine (GPC), a deacylatedphosphatidylcholine derivative, can influence the mitochondrial respiratory activity and in this way, may exert tissue protective effects. METHODS: Rat liver mitochondria were examined with high-resolution respirometry to analyze the effects of GPC on the electron transport chain in normoxic and anoxic conditions. Besides, Sprague-Dawley rats were subjected to sham operation or standardized liver ischemia-reperfusion (IR), with or without GPC administration...
2016: PloS One
https://www.readbyqxmd.com/read/27859855/dynamic-and-rapid-changes-in-the-transcriptome-and-epigenome-during-germination-and-in-developing-rice-oryza-sativa-coleoptiles-under-anoxia-and-re-oxygenation
#20
Reena Narsai, David Secco, Matthew D Schultz, Joseph R Ecker, Ryan Lister, James Whelan
Detailed molecular profiling of Oryza sativa (rice) was carried out to uncover the features that are essential to germination and early seedling growth under anoxic conditions. Temporal analysis of the transcriptome and methylome from germination to young seedlings under aerobic and anaerobic conditions revealed 82% similarity in the transcriptome and no differences in the epigenome up to 24-h. Following germination, significant transcriptomic and DNA methylation changes were observed between 4-d aerobic and anaerobic grown coleoptiles...
November 12, 2016: Plant Journal: for Cell and Molecular Biology
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