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Sophie S Abby, Michael Melcher, Melina Kerou, Mart Krupovic, Michaela Stieglmeier, Claudia Rossel, Kevin Pfeifer, Christa Schleper
Ammonia oxidizing archaea (AOA) of the phylum Thaumarchaeota are widespread in moderate environments but their occurrence and activity has also been demonstrated in hot springs. Here we present the first enrichment of a thermophilic representative with a sequenced genome, which facilitates the search for adaptive strategies and for traits that shape the evolution of Thaumarchaeota. Candidatus Nitrosocaldus cavascurensis has been enriched from a hot spring in Ischia, Italy. It grows optimally at 68°C under chemolithoautotrophic conditions on ammonia or urea converting ammonia stoichiometrically into nitrite with a generation time of approximately 23 h...
2018: Frontiers in Microbiology
Juan Ling, Xiancheng Lin, Yanying Zhang, Weiguo Zhou, Qingsong Yang, Liyun Lin, Siquan Zeng, Ying Zhang, Cong Wang, Manzoor Ahmad, Lijuan Long, Junde Dong
Seagrasses in coral reef ecosystems play important ecological roles by enhancing coral reef resilience under ocean acidification. However, seagrass primary productivity is typically constrained by limited nitrogen availability. Ammonia oxidation is an important process conducted by ammonia-oxidizing archaea (AOA) and bacteria (AOB), yet little information is available concerning the community structure and potential activity of seagrass AOA and AOB. Therefore, this study investigated the variations in the abundance, diversity and transcriptional activity of AOA and AOB at the DNA and transcript level from four sample types: the leaf, root, rhizosphere sediment and bulk sediment of seagrass Thalassia hemprichii in three coral reef ecosystems...
2018: Frontiers in Microbiology
Sarah Cohen, Nadine Puget, Yea-Lih Lin, Thomas Clouaire, Marion Aguirrebengoa, Vincent Rocher, Philippe Pasero, Yvan Canitrot, Gaëlle Legube
Ataxia with oculomotor apraxia 2 (AOA-2) and amyotrophic lateral sclerosis (ALS4) are neurological disorders caused by mutations in the gene encoding for senataxin (SETX), a putative RNA:DNA helicase involved in transcription and in the maintenance of genome integrity. Here, using ChIP followed by high throughput sequencing (ChIP-seq), we report that senataxin is recruited at DNA double-strand breaks (DSBs) when they occur in transcriptionally active loci. Genome-wide mapping unveiled that RNA:DNA hybrids accumulate on DSB-flanking chromatin but display a narrow, DSB-induced, depletion near DNA ends coinciding with senataxin binding...
February 7, 2018: Nature Communications
Linda Hink, Cécile Gubry-Rangin, Graeme W Nicol, James I Prosser
High and low rates of ammonium supply are believed to favour ammonia-oxidising bacteria (AOB) and archaea (AOA), respectively. Although their contrasting affinities for ammonium are suggested to account for these differences, the influence of ammonia concentration on AOA and AOB has not been tested under environmental conditions. In addition, while both AOB and AOA contribute to nitrous oxide (N2O) emissions from soil, N2O yields (N2O-N produced per NO2--N generated from ammonia oxidation) of AOA are lower, suggesting lower emissions when AOA dominate ammonia oxidation...
January 31, 2018: ISME Journal
M Ermel, T Behrendt, R Oswald, B Derstroff, D Wu, S Hohlmann, C Stönner, A Pommerening-Röser, M Könneke, J Williams, F X Meixner, M O Andreae, I Trebs, M Sörgel
Nitrous acid (HONO) is an important precursor of the hydroxyl radical (OH), the atmosphere´s primary oxidant. An unknown strong daytime source of HONO is required to explain measurements in ambient air. Emissions from soils are one of the potential sources. Ammonia-oxidizing bacteria (AOB) have been identified as possible producers of these HONO soil emissions. However, the mechanisms for production and release of HONO in soils are not fully understood. In this study, we used a dynamic soil-chamber system to provide direct evidence that gaseous emissions from nitrifying pure cultures contain hydroxylamine (NH2OH), which is subsequently converted to HONO in a heterogeneous reaction with water vapor on glass bead surfaces...
January 30, 2018: Scientific Reports
Xiaopeng Bai, Eikichi Ihara, Katsuya Hirano, Yoshimasa Tanaka, Kayoko Nakano, Satomi Kita, Takahiro Iwamoto, Haruei Ogino, Mayumi Hirano, Yoshinao Oda, Kazuhiko Nakamura, Yoshihiro Ogawa
Background and Aims: Hydrogen sulfide (H2S) is a major physiologic gastrotransmitter. Its role in the regulation of the lower esophageal sphincter (LES) function remains unknown. The present study addresses this question. Methods: Isometric contraction was monitored in circular smooth muscle strips of porcine LES. Changes in cytosolic Ca2+ concentration ([Ca2+]i) and force were simultaneously monitored in fura-2-loaded strips with front-surface fluorometry. The contribution of endogenous H2S to LES contractility was investigated by examining the effects of inhibitors of H2S-generating enzymes, including cystathionine-β-synthase, cystathionine-γ-lyase, and 3-mercaptopyruvate sulfurtransferase, on the LES function...
March 2018: Cellular and Molecular Gastroenterology and Hepatology
Changjuan Shan, Shengli Zhang, Xingqi Ou
This paper investigated the roles of hydrogen sulfide (H2S) and hydrogen peroxide (H2O2) and the possible relationship between them in regulating the AsA-GSH cycle in wheat leaves under drought stress (DS). Results showed that DS markedly increased the production of H2S and H2O2, the transcript levels and activities of ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), and dehydroascorbate reductase (DHAR); malondialdehyde (MDA) content; and electrolyte leakage (EL)...
January 25, 2018: Protoplasma
Mingcong Li, Guangshan Wei, Wenchong Shi, Zhongtao Sun, Han Li, Xiaoyun Wang, Zheng Gao
Ammonia oxidation is a critical process of estuarine nitrogen cycling involving ammonia-oxidizing archaea (AOA) and bacteria (AOB). However, the distribution patterns of ammonia-oxidizing microorganisms (AOMs) between different habitats in the same area remain unclear. The present study investigated the AOMs' abundance and community compositions in both sediment and water habitats of the Yellow River estuary. Quantitative PCR (qPCR) revealed that AOA showed significant higher abundance than AOB both in sediment and water samples...
January 25, 2018: Scientific Reports
Zhigang Han, Jingjie Zhang, Shengguan Cai, Xiaohui Chen, Xiaoyan Quan, Guoping Zhang
BACKGROUND: The interest has been increasing on the phenolic compounds in plants because of their nutritive function as food and the roles regulating plant growth. However, their underlying genetic mechanism in barley is still not clear. RESULTS: A genome-wide association study (GWAS) was conducted for total phenolic content (TPC), total flavonoid content (FLC) and antioxidant activity (AOA) in 67 cultivated and 156 Tibetan wild barley genotypes. Most markers associated with phenolic content were different in cultivated and wild barleys...
January 25, 2018: BMC Genomics
Pratik Bankhele, Ankita Salvi, Jamal Jamil, Fatou Njie-Mbye, Sunny Ohia, Catherine A Opere
We investigated the pharmacological actions of a slow-releasing H2S donor, GYY 4137; a substrate for the biosynthesis of H2S, L-cysteine and its precursor, N-acetylcysteine on potassium (K+; 50 mM)-evoked [3H]D-aspartate release from bovine isolated retinae using the Superfusion Method. GYY 4137 (10 nM-10 µM), L-cysteine (100 nM-10 µM) and N-acetylcysteine (10 µM-1 mM) elicited a concentration-dependent decrease in K+-evoked [3H]D-aspartate release from isolated bovine retinae without affecting basal tritium efflux...
January 20, 2018: Neurochemical Research
Marziyeh Tavalaee, Michail Nomikos, F Anthony Lai, Mohammad Hossein Nasr-Esfahani
Globozoospermia is characterized by the presence of 100% acrosomeless round-headed spermatozoa in an ejaculate. Failed fertilization after intracytoplasmic sperm injection (ICSI) is commonly reported for globozoospermic couples and can be overcome by artificial oocyte activation (AOA). Phospholipase C zeta (PLCζ) is one of the main sperm factors involved in oocyte activation and its low expression levels mainly account for fertilization failure. Deletion of the DPY19L2 gene is reported as a main genetic cause in over 70% of infertile men with globozoospermia...
December 29, 2017: Reproductive Biomedicine Online
M Ferrer-Buitrago, L Dhaenens, Y Lu, D Bonte, F Vanden Meerschaut, P De Sutter, L Leybaert, B Heindryckx
STUDY QUESTION: Can human oocyte calcium analysis predict fertilization success after assisted oocyte activation (AOA) in patients experiencing fertilization failure after ICSI? SUMMARY ANSWER: ICSI-AOA restores the fertilization rate only in patients displaying abnormal Ca2+ oscillations during human oocyte activation. WHAT IS KNOWN ALREADY: Patients capable of activating mouse oocytes and who showed abnormal Ca2+ profiles after mouse oocyte Ca2+ analysis (M-OCA), have variable responses to ICSI-AOA...
January 10, 2018: Human Reproduction
Yuechao Lu, Davina Bonte, Minerva Ferrer-Buitrago, Mina Popovic, Jitesh Neupane, Margot Van der Jeught, Luc Leybaert, Petra De Sutter, Björn Heindryckx
Inconsistent fertilisation and pregnancy rates have been reported by different laboratories after application of ionomycin as a clinical method of assisted oocyte activation (AOA) to overcome fertilisation failure. Using both mouse and human oocytes, in the present study we investigated the effects of ionomycin and Ca2+ concentrations on the pattern of Ca2+ release and embryonic developmental potential. In the mouse, application of 5μM ionomycin in potassium simplex optimisation medium (KSOM) or 10µM ionomycin in Ca2+-free KSOM significantly reduced the Ca2+ flux and resulted in failure of blastocyst formation compared with 10μM ionomycin in KSOM...
January 12, 2018: Reproduction, Fertility, and Development
Reşat Apak, Sema Demirci Çekiç, Ayşem Üzer, Saliha Esin Çelik, Mustafa Bener, Burcu Bekdeşer, Ziya Can, Şener Sağlam, Ayşe Nur Önem, Erol Erçağ
Since an unbalanced excess of reactive oxygen/nitrogen species (ROS/RNS) causes various diseases, determination of antioxidants that can counter oxidative stress is important in food and biological analyses. Optical/electrochemical nanosensors have attracted attention in antioxidant activity (AOA) assessment because of their increased sensitivity and selectivity. Optical sensors offer advantages such as low cost, flexibility, remote control, speed, miniaturization and on-site/in situ analysis. Electrochemical sensors using noble metal nanoparticles on modified electrodes better catalyze bioelectrochemical reactions...
January 11, 2018: Sensors
Papitchaya Srithep, Preeyaporn Pornkulwat, Tawan Limpiyakorn
In this study, two laboratory nitrifying reactors (NRI and NRII), which were seeded by sludge from different sources and operated under different operating conditions, were found to possess distinct dominant ammonia-oxidizing microorganisms. Ammonia-oxidizing archaeal (AOA) amoA genes outnumbered ammonia-oxidizing bacterial (AOB) amoA genes in reactor NRI, while only AOB amoA genes were detectable in reactor NRII. The AOA amoA gene sequences retrieved from NRI were characterized within the Nitrososphaera sister cluster of the group 1...
January 10, 2018: Environmental Science and Pollution Research International
Jennifer Bennett, Steven P Verney
Research has demonstrated that bilingualism impacts neuropsychological performance, but the findings on its effects on verbal fluency have been mixed. This study compared the verbal fluency performance of non-Hispanic White monolingual speakers with a Hispanic bilingual population. Ninety-nine Spanish-English bilingual Hispanic and thirty English-speaking monolingual non-Hispanic White undergraduates completed the Controlled Oral Word Association Test (COWAT). Students also completed a general cognitive and English reading measure...
January 9, 2018: Applied Neuropsychology. Adult
Kuo Du, Jeongeun Hyun, Richard T Premont, Steve S Choi, Gregory A Michelotti, Marzena Swiderska-Syn, George D Dalton, Eric Thelen, Bahar Salimian Rizi, Youngmi Jung, Anna Mae Diehl
BACKGROUND & AIMS: Cirrhosis results from accumulation of myofibroblasts derived from quiescent hepatic stellate cells (Q-HSCs); it regresses when myofibroblastic HSCs are depleted. Hedgehog signaling promotes transdifferentiation of HSCs by activating Yes-associated protein 1 (YAP1 or YAP) and inducing aerobic glycolysis. However, increased aerobic glycolysis alone cannot meet the high metabolic demands of myofibroblastic HSCs. Determining the metabolic processes of these cells could lead to strategies to prevent progressive liver fibrosis, so we investigated whether glutaminolysis (conversion of glutamine to alpha-ketoglutarate) sustains energy metabolism and permits anabolism when Q-HSCs become myofibroblastic, and whether this is controlled by hedgehog signaling to YAP...
January 3, 2018: Gastroenterology
Huanhuan Wang, Xu Li, Xiang Li, Xinyu Li, Jian Wang, Huiwen Zhang
Microbial communities play critical roles in soil nitrogen (N) cycle; however, we have limited understanding of the distribution of N-cycling microbial groups in deeper soil horizons. In this study, we used quantitative PCR to characterize the changes of microbial populations (16S rRNA and 18S rRNA) and five key N-cycling gene abundances involved in N fixation (nifH), ammonia oxidation (amoA) by ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA), and nitrite reduction (nirS and nirK) along profiles (0-100 cm depth) of different paddy soils from three regions (Hailun, Changshu, Yingtan) across China from north to south...
2017: PloS One
Alex Miklashevsky
A number of new psycholinguistic variables has been proposed during the last years within embodied cognition framework: modality experience rating (i.e., relationship between words and images of a particular perceptive modality-visual, auditory, haptic etc.), manipulability (the necessity for an object to interact with human hands in order to perform its function), vertical spatial localization. However, it is not clear how these new variables are related to each other and to such traditional variables as imageability, AoA and word frequency...
December 27, 2017: Journal of Psycholinguistic Research
Jinhua Wang, Lanjun Wang, Lusheng Zhu, Jun Wang
The negative effects of residues from antibiotics and heavy metals in agricultural soils are becoming an increasingly frequent concern. To evaluate the toxicity and interaction of antibiotics and heavy metals, enrofloxacin (ENR) and cadmium (Cd) were used as targets to study the individual effects of ENR (0.025, 0.1, 0.4mmol/kg) and Cd (0.4mmol/kg) and their combined effects (mole ratios of ENR to Cd of 1: 1, 1: 4 and 1: 16) on soil microbial biomass and function on days 7, 14, 21 and 28 of the study. The results demonstrated that microbial populations, which were counted during 4 sampling periods, were mainly in the order of bacteria>actinomycetes>fungi...
December 20, 2017: Science of the Total Environment
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