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Nitrate reducing bacteria

Hajar Naseri, Asghar Sharifi, Mehrorang Ghaedi, Kheibar Dashtian, Seyed Sajad Khoramrooz, Leila Manzouri, Seyed Abdolmajid Khosravani, Vahid Pezeshkpour, Farzad Sadri, Marzieh Askarinia
The cytosine embedded copper based metal-organic framework (Bio-MOF) was synthesized by facile one-step sonochemical method by simply mixing of 4-4, biphenyldicarboxylic, cytosine and copper nitrate (Bio-Cu-H2 bpdc-Cy). The prepared bio-MOF was characterized by XRD, FTIR and FE-SEM techniques. The effect of Cu-H2 bpdc-Cy on the expression of the rsbA gene was evaluated in the clinical and standard Proteus mirabilis and study of MIC of Cu-H2 bpdc-Cy by microdilution against them that have the rsbA gene. According to different concentrations of MIC, MBC concentrations was cultured on blood agar culture medium...
June 2018: Ultrasonics Sonochemistry
James Jamieson, Henning Prommer, Anna Kaksonen, Jing Sun, Adam Siade, Anna Yusov, Benjamin C Bostick
Microbially driven nitrate-dependent iron (Fe) oxidation (NDFO) in subsurface environments has been intensively studied. However, the extent to which Fe(II) oxidation is biologically catalyzed remains unclear because no neutrophilic iron-oxidizing and nitrate reducing autotroph has been isolated to confirm the existence of an enzymatic pathway. While mixotrophic NDFO bacteria have been isolated, understanding the process is complicated by simultaneous abiotic oxidation due to nitrite produced during denitrification...
April 20, 2018: Environmental Science & Technology
Chao Peng, Anneli Sundman, Casey Bryce, Charlotte Catrouillet, Thomas Borch, Andreas Kappler
Fe(II)-organic-matter (Fe(II)-OM) complexes are abundant in the environment and may play a key role for the behavior of Fe and pollutants. Mixotrophic nitrate-reducing Fe(II)-oxidizing bacteria (NRFeOx) reduce nitrate coupled to the oxidation of organic compounds and Fe(II). Fe(II) oxidation may occur enzymatically or abiotically by reaction with nitrite that forms during heterotrophic denitrification. However, it is unknown whether Fe(II)-OM complexes can be oxidized by NRFeOx. We used cell-suspension experiments with the mixotrophic nitrate-reducing Fe(II)-oxidizing bacterium Acidovorax sp...
April 19, 2018: Environmental Science & Technology
Liangying Zhang, Haohao Sun, Xu-Xiang Zhang, Hongqiang Ren, Lin Ye
Nitrate-dependent Fe(II) oxidation (NDFO) has been discovered in various environments including activated sludge and can potentially be used to remove nitrate from wastewater. In this study, NDFO sludge was successfully enriched from activated sludge under high Fe(II) concentrations over 100 days and the denitrification rate achieved 1.37 mmol N/(gVSS day). High-throughput sequencing of the bacterial 16S rRNA gene was used to investigate the microbial community structure dynamics during the enrichment process...
April 11, 2018: Applied Microbiology and Biotechnology
Ge Ren, Anzhou Ma, Yanfen Zhang, Ye Deng, Guodong Zheng, Xuliang Zhuang, Guoqiang Zhuang, Danielle Fortin
Mud volcanoes (MVs) emit globally significant quantities of methane into the atmosphere, however, methane cycling in such environments is not yet fully understood, as the roles of microbes and their associated biogeochemical processes have been largely overlooked. Here, we used data from high-throughput sequencing of microbial 16S rRNA gene amplicons from six MVs in the Junggar Basin in northwest China to quantify patterns of diversity and characterize the community structure of archaea and bacteria. We found anaerobic methanotrophs and diverse sulfate- and iron-reducing microbes in all of the samples, and the diversity of both archaeal and bacterial communities was strongly linked to the concentrations of sulfate, iron, and nitrate, which could act as electron acceptors in anaerobic oxidation of methane (AOM)...
April 6, 2018: Environmental Microbiology
Ouwei Wang, Ryan A Melnyk, Misha G Mehta-Kolte, Matthew D Youngblut, Hans K Carlson, John D Coates
Most dissimilatory perchlorate reducing bacteria (DPRB) are also capable of respiratory nitrate reduction, and preferentially utilize nitrate over perchlorate as a terminal electron acceptor. The similar domain architectures and phylogenetic relatedness of the nitrate and perchlorate respiratory complexes suggests a common evolutionary history and a potential for functionally redundant electron carriers. In this study, we identify key genetic redundancies in the electron transfer pathways from the quinone pool(s) to the terminal nitrate and perchlorate reductases in Azospira suillum PS (hereafter referred to as PS)...
2018: Frontiers in Microbiology
Balaram Mohapatra, Pinaki Sar, Sufia Khannam Kazy, Mrinal Kumar Maiti, Tulasi Satyanarayana
Reductive transformation of toxic arsenic (As) species by As reducing bacteria (AsRB) is a key process in As-biogeochemical-cycling within the subsurface aquifer environment. In this study, we have characterized a Gram-stain-negative, non-spore-forming, rod-shaped As reducing bacterium designated KAs 5-3T, isolated from highly As-contaminated groundwater of India. Strain KAs 5-3T displayed high 16S rRNA gene sequence similarity to the members of the genus Pseudoxanthomonas, with P. mexicana AMX 26BT (99.25% similarity), P...
2018: PloS One
Nathan S Bryan
PURPOSE OF REVIEW: To reveal the mechanisms of nitric oxide (NO) production in humans and how lifestyle, drug therapy, and hygienic practices can decrease NO production. Furthermore, to show how functional nitric oxide nutrition can overcome these limitations to restore endogenous NO production and combat cardiovascular disease. RECENT FINDINGS: Research over the past decade has revealed that inorganic nitrate and nitrite found naturally in green leafy vegetables and other vegetables such as beets can provide the human body with a source of bioactive nitric oxide...
March 17, 2018: Current Atherosclerosis Reports
Mia C Burleigh, Luke Liddle, Chris Monaghan, David J Muggeridge, Nicholas Sculthorpe, John P Butcher, Fiona L Henriquez, Jason D Allen, Chris Easton
Nitric oxide (NO) can be generated endogenously via NO synthases or via the diet following the action of symbiotic nitrate-reducing bacteria in the oral cavity. Given the important role of NO in smooth muscle control there is an intriguing suggestion that cardiovascular homeostasis may be intertwined with the presence of these bacteria. Here, we measured the abundance of nitrate-reducing bacteria in the oral cavity of 25 healthy humans using 16S rRNA sequencing and observed, for 3.5hours, the physiological responses to dietary nitrate ingestion via measurement of blood pressure, and salivary and plasma NO metabolites...
March 14, 2018: Free Radical Biology & Medicine
Mikk Espenberg, Marika Truu, Ülo Mander, Kuno Kasak, Hiie Nõlvak, Teele Ligi, Kristjan Oopkaup, Martin Maddison, Jaak Truu
Tropical peatlands, which play a crucial role in the maintenance of different ecosystem services, are increasingly drained for agriculture, forestry, peat extraction and human settlement purposes. The present study investigated the differences between natural and drained sites of a tropical peatland in the community structure of soil bacteria and archaea and their potential to perform nitrogen transformation processes. The results indicate significant dissimilarities in the structure of soil bacterial and archaeal communities as well as nirK, nirS, nosZ, nifH and archaeal amoA gene-possessing microbial communities...
March 16, 2018: Scientific Reports
Jasmin Frey, Fabian Schneider, Thomas Huhn, Dieter Spiteller, Bernhard Schink, David Schleheck
Degradation of acetone by the sulfate-reducing bacterium Desulfococcus biacutus involves an acetone-activation reaction different from that used by aerobic or nitrate-reducing bacteria, because the small energy budget of sulfate-reducing bacteria does not allow for major expenditures into ATP-consuming carboxylation reactions. In the present study, an inducible coenzyme B12 -dependent conversion of 2-hydroxyisobutyryl-CoA to 3-hydroxybutyryl-CoA was demonstrated in cell-free extracts of acetone-grown D. biacutus cells, together with a NAD+ -dependent oxidation of 3-hydroxybutyryl-CoA to acetoacetyl-CoA...
March 12, 2018: Environmental Microbiology Reports
Muhe Diao, Jef Huisman, Gerard Muyzer
Sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) drive major transformations in the sulfur cycle, and play vital roles in oxic-anoxic transitions in lakes and coastal waters. However, information on the succession of these sulfur bacteria in seasonally stratified lakes using molecular biological techniques is scarce. Here, we used 16S rRNA gene amplicon sequencing to study the spatio-temporal dynamics of sulfur bacteria during oxic-anoxic regime shifts in Lake Vechten. Oxygen and sulfate were mixed throughout the water column in winter and early spring...
March 8, 2018: FEMS Microbiology Ecology
Paul Whitehead, Gianbattista Bussi, Mohammed Abed Hossain, Michaela Dolk, Partho Das, Sean Comber, Rebecca Peters, Katrina J Charles, Rob Hope, Sarwar Hossain
River water quality in rapidly urbanising Asian cities threatens to damage the resource base on which human health, economic growth and poverty reduction all depend. Dhaka reflects the challenges and opportunities for balancing these dynamic and complex trade-offs which goals can be achieved through effective policy interventions. There is a serious problem of water pollution in central Dhaka, in the Turag-Tongi-Balu River system in Bangladesh with the river system being one of the most polluted in the world at the moment...
March 8, 2018: Science of the Total Environment
Peng Yan, Jin-Song Guo, Yu-Feng Xu, You-Peng Chen, Jing Wang, Zhi-Ping Liu, Fang Fang
Sludge reduction based on regulating substrate allocation between catabolism and anabolism as a strategy is proposed to reduce energy and chemicals consumption during wastewater treatment. The results indicated that a sludge reduction of 14.8% and excellent nutrient removal were simultaneously achieved in the low dissolved oxygen (LDO) activated sludge system with a hydraulic retention time of 24 h at 25 °C. Denitrifiers comprised nearly 1/4 of all microorganisms in the system. These denitrifiers converted NOx - to N2 obtaining a lower biomass yield...
February 17, 2018: Bioresource Technology
Zsuzsanna Nagymáté, Katalin Nemes-Barnás, Gergely Krett, Károly Márialigeti
This study provides a comprehensive microbiological survey of three drinking water networks applying different water treatment processes. Variability of microbial communities was assessed by cultivation-based [nitrifying, denitrifying most probable number (MPN) heterotrophic plate count] and sequence-aided terminal restriction fragment length polymorphism (T-RFLP) analysis. The effect of microbial community composition on nitrifying MPN values was revealed. The non-treated well water samples showed remarkable differences to their corresponding distribution systems regarding low plate count, nitrifying MPN, and the composition of microbial communities, which increased and changed, respectively, in distribution systems...
February 23, 2018: Acta Microbiologica et Immunologica Hungarica
Junwen Zhang, Teng Ma, Yani Yan, Xianjun Xie, Olusegun K Abass, Congqiang Liu, Zhiqi Zhao, Zhizhen Wang
High arsenic groundwater generally coexists with elevated Fe2+ concentrations (mg L-1 levels) under reducing conditions, but an explanation for the extremely high arsenic (up to ∼2690) concentrations at very low Fe2+ (i.e., μg L-1 levels) in groundwater of Datong Basin remains elusive. Field groundwater investigation and laboratory microcosm experiments were implemented in this study. The field groundwater was characterized by weakly alkaline (pH 7.69 to 8.34) and reducing conditions (Eh -221.7 to -31...
February 18, 2018: Environmental Pollution
Seong-Jun Chun, Yingshun Cui, Chi-Yong Ahn, Hee-Mock Oh
A highly settleable microalga, Ettlia sp., was applied to a freshwater recirculating aquaculture system (RAS) of Danio rerio to improve the treatment of nitrogenous compounds. The growth characteristics of the microalgae, water quality parameters, and bacterial communities were monitored for 73 days. In the treatment RAS, the inoculated Ettlia sp. grew up to 1.26 g/L and dominated (>99%) throughout the experiment, whereas naturally occurring microalgae grew to 0.57 g/L in the control RAS. The nitrate, nitrite, and ammonium concentrations in the treatment RAS were reduced by 50...
February 8, 2018: Water Research
Yuzhi Wu, Jian-Wen Qiu, Pei-Yuan Qian, Yong Wang
In deep-sea cold seeps, microbial communities are shaped by geochemical components in seepage solutions. In the present study, we report the composition of microbial communities and potential metabolic activities in the surface sediment of Jiaolong cold seep at the northern South China Sea. Pyrosequencing of 16S rRNA gene amplicons revealed that a majority of the microbial inhabitants of the surface layers (0-6 cm) were sulfur oxidizer bacteria Sulfurimonas and archaeal methane consumer ANME-1, while sulfate reducer bacteria SEEP-SRB1, ANME-1 and ANME-2 dominated the bottom layers (8-14 cm)...
February 13, 2018: Extremophiles: Life Under Extreme Conditions
Karin E Eriksson, Ting Yang, Mattias Carlström, Eddie Weitzberg
Numerous studies have shown beneficial cardiovascular and metabolic effects of dietary nitrate but the release or uptake of these anions on an organ level is still poorly elucidated. Here we administered sodium nitrate in the pig and measured acute changes in release/uptake of nitrate and nitrite across several organs as well as cardiovascular and metabolic functions. In 17 anesthetized pigs multiple venous catheters and arterial ultrasonic blood flow probes were positioned. After pretreatment with the NO synthase (NOS) inhibitor l-NAME to minimize involvement of NOS-dependent nitrate/nitrite generation, the animals received bolus injections of either sodium nitrate or sodium chloride...
February 8, 2018: Nitric Oxide: Biology and Chemistry
Congcong Zhang, Lanmei Zhao, Mutai Bao, Jinren Lu
Potential of hydrolyzed polyacrylamide (HPAM) biodegradation to final products was studied through regulating its own nitrogen transformation. Under the conditions of 2, 3 and 4 mg/L of DO, HPAM removal ratio reached 16.92%, 24.51% and 30.78% and the corresponding removal ratio reached 49.15%, 60.25% and 76.44% after anaerobic biodegradation. NO3--N concentration was 9.43, 14.10 and 17.99 mg/L in aerobic stages and the corresponding concentration was 0.17, 0.07 and 0.008 mg/L after anaerobic biodegradation...
February 2, 2018: Bioresource Technology
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