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Nitrate reducing bacteria

Hui Yun, Bin Liang, Deyong Kong, Aijie Wang
Bioelectrochemical systems (BESs) have been tentatively applied for wastewater treatment processes, but the complex composition of wastewater could lead to difficulties in establishing functional biofilm or result in performance instability. Few studies have investigated the enrichment of biocathode with domestic wastewater (DW) and the function. A biocathode with multi-pollutant removal capabilities was enriched based on polarity inverted bioanode, which was established with DW. The biocathode function was examined using model pollutants (nitrate, nitrobenzene and Acid Orange 7) supplemented as sole or mixed electron acceptors...
December 7, 2017: Chemosphere
Her Shuang Toh, Roxanne Line Faure, Liyana Bte Mohd Amin, Crystal Yu Fang Hay, Saji George
This article presents a simple, one-step, in situ generation of silver nanoparticle-functionalized fabrics with antibacterial properties, circumventing the conventional, multistep, time-consuming methods. Silver nanoparticle formation was studied with a library of capping agents (branched polyethylenimine [BPEI] of molecular weight [Mw] 10,000 and 25,000, polyvinylpyrrolidone, polyethylene glycol, polyvinylalcohol and citrate) mixed with silver nitrate. The mixture was then exposed to an assortment of light wavelengths (ultraviolet, infrared and simulated solar light) for studying the light-assisted synthesis of nanoparticles...
2017: Nanotechnology, Science and Applications
Alexis Fonseca, Thomas Ishoey, Carola Espinoza, Danilo Pérez-Pantoja, Antonio Manghisi, Marina Morabito, Alexis Salas-Burgos, Víctor A Gallardo
The Humboldt Sulfuretum (HS), in the productive Humboldt Eastern Boundary Current Upwelling Ecosystem, extends under the hypoxic waters of the Peru-Chile Undercurrent (ca. 6°S and ca. 36°S). Studies show that primeval sulfuretums held diverse prokaryotic life, and, while rare today, still sustain species-rich giant sulfur-oxidizing bacterial communities. We here present the genomic features of a new bacteria of the HS, "Candidatus Venteria ishoeyi" ("Ca. V. ishoeyi") in the family Thiotrichaceae.Three identical filaments were micro-manipulated from reduced sediments collected off central Chile; their DNA was extracted, amplified, and sequenced by a Roche 454 GS FLX platform...
2017: PloS One
K Ghyselbrecht, A Monballiu, M H Somers, I Sigurnjak, E Meers, L Appels, B Meesschaert
Anaerobic digestion is widely used to produce renewable energy. However, the main drawback is the limited conversion efficiency of organic matter. Applying an advanced oxidation process (AOP) as a digestate post-treatment is able to increase this conversion efficiency but will also lead to the oxidation of ammonium to nitrite or nitrate. In this lab scale study, the fate of the latter in the digester was investigated. Nitrite and nitrate were therefore added in concentrations that could arise from rate limiting ammonium concentrations (1...
December 8, 2017: Environmental Technology
Chunjing Liu, Jianzhi Xie, Manli Song, Zhiling Gao, Dongxing Zheng, Xia Liu, Guohui Ning, Xu Cheng, Harry Bruning
Poor nitrogen removal efficiency (mainly nitrate, NO3--N) at low temperatures strongly limits application of subsurface wastewater infiltration systems (SWISs). Seven psychrophilic strains (heterotrophic nitrifying bacteria and aerobic denitrifying bacteria) were isolated and added to SWISs to investigate the effect of embedding and direct-dosing bioaugmentation strategies on sewage treatment performance at low temperature. Both bioaugmentation strategies improved ammonium (NH4+-N) removal efficiencies, and the embedding strategy also exhibited satisfactory NO3--N and total nitrogen (TN) removal efficiencies...
December 2, 2017: Bioresource Technology
Yujie Fang, Yonglu Wang, Zongdong Liu, Binghuai Lu, Hang Dai, Biao Kan, Duochun Wang
Two strains, 08MAS2251T and LZ2016-166, were isolated from diverse samples in China collected from the surface of crucian carp and the faeces of a diarrhoea patient, respectively. Both strains were pink-orange coloured, Gram-negative, oxidase- and catalase-positive, facultative anaerobic and motile bacteria, produced H2S and reduced nitrates to nitrites. Growth occurred in the presence of 0-9 % (w/v) NaCl and at 10-42 °C. The optimum conditions were with 1 % (w/v) NaCl and at 35 °C. The phylogenetic tree of 16S rRNA gene demonstrated that strains 08MAS2251T and LZ2016-166 clustered in a distinctive clade next to the species Shewanella chilikensis JC5T within the genus Shewanella...
December 5, 2017: International Journal of Systematic and Evolutionary Microbiology
Feifei Wang, Doris van Halem, Lei Ding, Ying Bai, Karin Lekkerkerker-Teunissen, Jan Peter van der Hoek
The removal of bromate (BrO3-) as a by-product of ozonation in subsequent managed aquifer recharge (MAR) systems, specifically in anoxic nitrate (NO3-)-reducing zones, has so far gained little attention. In this study, batch reactors and columns were used to explore the influence of NO3- and increased assimilable organic carbon (AOC) due to ozonation pre-treatment on BrO3- removal in MAR systems. 8 m column experiments were carried out for 10 months to investigate BrO3- behavior in anoxic NO3--reducing zones of MAR systems...
November 27, 2017: Water Research
Robert P Allaker, Abish S Stephen
Purpose of Review: The purpose of this study is to critically assess recent studies concerning the use of probiotics to control periodontal diseases, dental caries and halitosis (oral malodour). Recent Findings: Clinical studies have shown that probiotics when allied to conventional periodontal treatment can ameliorate microbial dysbiosis and produce significant improvement in clinical indicators of disease. However, this effect is often not maintained by the host after the end of probiotic use...
2017: Current Oral Health Reports
Florian Mauffrey, Alexandra Cucaita, Philippe Constant, Richard Villemur
Background: Methylophaga nitratireducenticrescens strain JAM1 is a methylotrophic, marine bacterium that was isolated from a denitrification reactor treating a closed-circuit seawater aquarium. It can sustain growth under anoxic conditions by reducing nitrate ([Formula: see text]) to nitrite ([Formula: see text]). These physiological traits are attributed to gene clusters that encode two dissimilatory nitrate reductases (Nar). Strain JAM1 also contains gene clusters encoding two nitric oxide (NO) reductases and one nitrous oxide (N2O) reductase, suggesting that NO and N2O can be reduced by strain JAM1...
2017: PeerJ
Zhenzhu Chen, Junyi Zhang, Rui Li, Fei Tian, Yanting Shen, Xueying Xie, Qinyu Ge, Zuhong Lu
Molecular mechanism of interaction between the bloom-forming cyanobacterial species and attached microbios within cyanobacterial aggregates has not been elucidated yet and understanding of which would help to unravel the cyanobacteria bloom-forming mechanism. In this study, we profiled the metabolically active community by high-throughput metatranscriptome sequencing from cyanobacterial aggregates during cyanobacterial bloom period in Lake Taihu, China. A total of 308 million sequences were obtained using the HiSeq 2500 sequencing platform, which provided a great sequence coverage to carry out the in-depth taxonomic classification, functional classification, and metabolic pathway analysis of the cyanobacterial aggregates...
December 3, 2017: Environmental Science and Pollution Research International
Souad Christieans, Laurent Picgirard, Emilie Parafita, André Lebert, Thierry Gregori
Salmonella and Listeria monocytogenes are two pathogenic bacteria that most frequently contaminate pork meat. In dry fermented sausages, several hurdles are used for controlling bacterial growth such as nitrite and salt addition. In Europe, practices consist of adding potassium nitrate (250ppm expressed as NaNO3) or a combination of nitrate/nitrite (150/150ppm expressed as NaNO3/NaNO2 respectively). However, involvement of these additives in nitrosamine formation is a matter of concern. Consequently, a decrease in nitrite/nitrate amounts is proposed...
November 22, 2017: Meat Science
Y Shen, A Agrawal, N K Suri, D An, J K Voordouw, R G Clark, T R Jack, K Miner, R Pederzolli, A Benko, G Voordouw
Oil production by water injection often involves the use of makeup water to replace produced oil. Sulfate in makeup water is reduced by sulfate-reducing bacteria to sulfide, a process referred to as souring. In the MHGC field souring was caused by using makeup water with 4mM (384ppm) sulfate. Mixing with sulfate-free produced water gave injection water with 0.8mM sulfate. This was amended with nitrate to limit souring and was then distributed fieldwide. The start-up of an enhanced-oil-recovery pilot caused all sulfate-containing makeup water to be used for dissolution of polymer, which was then injected into a limited region of the field...
November 29, 2017: Journal of Biotechnology
Ian T Cadby, Matthew Faulkner, Jeanne Cheneby, Justine Long, Jacques van Helden, Alain Dolla, Jeffrey A Cole
The sulfate reducing bacterium Desulfovibrio desulfuricans inhabits both the human gut and external environments. It can reduce nitrate and nitrite as alternative electron acceptors to sulfate to support growth. Like other sulphate reducing bacteria, it can also protect itself against nitrosative stress caused by NO generated when nitrite accumulates. By combining in vitro experiments with bioinformatic and RNA-seq data, metabolic responses to nitrate or NO and how nitrate and nitrite reduction are coordinated with the response to nitrosative stress were revealed...
November 24, 2017: Scientific Reports
Tangqing Wu, Cheng Sun, Wei Ke
Although many mechanisms have been proposed to explain the microbiologically assisted cracking (MAC) of steel and copper, a theoretical interpretation is necessary. In this paper, we attempt to give a theoretical interpretation of sulfate/nitrate reducing bacteria (SRB/NRB)-assisted cracking using Ee-pH diagrams. Under the combined actions of SRB/NRB and external stress, the cell potential (Ecell) and the corrosion current density of the corrosion reaction increase, such that the corrosion reactions become more thermodynamically favorable...
November 16, 2017: Bioelectrochemistry
Sathish Sundar Dhilip Kumar, Nicolette Nadene Houreld, Eve M Kroukamp, Heidi Abrahamse
In recent years, silver nanoparticles (AgNPs) have attracted significant attention in medicinal, biomedical, and pharmaceutical research owing to their valuable physicochemical and antibacterial properties. Leaf sap extract (LSE) from Aloe arborescens can be used as an active ingredient for different biological applications, including wound healing. In this study, we have investigated the use of LSE from A. arborescens as a reducing, stabilizing and capping agent to produce AgNPs during the so called "green synthesis" (G-AgNPs)...
November 3, 2017: Journal of Photochemistry and Photobiology. B, Biology
Yue Zhang, Yu-Rong Liu, Pei Lei, Yong-Jie Wang, Huan Zhong
There is growing evidence that incorporating crop straw into soils, which is being widely encouraged in many parts of the world, could increase net methylmercury (MeHg) production in soils and MeHg accumulation in crops. We explored the possibility of mitigating the risk of increased MeHg levels under straw amendment by transforming straw into biochar (BC). Greenhouse and batch experiments were conducted, in which soil MeHg concentrations, MeHg phytoavailability and accumulation in rice, dynamics of sulfate, nitrate and abundances of sulfate reducing bacteria (SRB) were compared in 'Control' (Hg contaminated soil), 'Straw' (soil with 1% rice straw), 'Straw+BC' (soil with 1% straw and 1% biochar), and 'Straw+BC+N' (soil with 1% straw, 1% biochar and 0...
November 17, 2017: Science of the Total Environment
Rafaela Cáceres, Krystyna Malińska, Oriol Marfà
Composting could be regarded as a process of processes because it entails a number of complex chemical and microbiological reactions and transformations. Nitrification is one of such processes that normally takes place during the curing phase. This process has been studied in detail for wastewater treatment, and it is becoming an extensively studied topic within composting. In the past, nitrate presence in compost has been clearly perceived as a maturation indicator; however, nowadays, nitrate formation is also conceived as a way of conserving nitrogen in compost...
November 15, 2017: Waste Management
Yuexia Wu, Ligang Xu, Sai Wang, Zhenglu Wang, Jianying Shang, Xiqing Li, Chunmiao Zheng
This study investigated nitrate attenuation in low-permeability sediments (LPS) in a multi-layer aquifer by integrating hydrochemical, isotopic and microbiological molecular techniques in a field site. In the meantime, the overlying high-permeability sediment (HPS) was also examined on the nitrate attenuation for the sake of comparison. Additionally, laboratory flow-through experiments were conducted to assess the overall nitrate reduction rate in the two types of sediment. The δ(15)N-NO3(-) and δ(34)S-SO4(2-) values were more enriched by approximately 37‰ and 15‰ in the LPS than the overlying HPS associated with substantial reductions of the NO3(-) and SO4(2-) concentration, indicating the occurrence of strong bio-reductions in nitrate and sulfate...
November 7, 2017: Science of the Total Environment
Imtiaz Hussain Raja Abbasi, Farzana Abbasi, Mohamed E Abd El-Hack, Mervat A Abdel-Latif, Rab N Soomro, Khawar Hayat, Mohamed A E Mohamed, Bello M Bodinga, Junhu Yao, Yangchun Cao
Protein quality plays a key role than quantity in growth, production, and reproduction of ruminants. Application of high concentration of dietary crude protein (CP) did not balance the proportion of these limiting amino acids (AA) at duodenal digesta of high producing dairy cow. Thus, dietary supplementation of rumen-protected AA is recommended to sustain the physiological, productive, and reproductive performance of ruminants. Poor metabolism of high CP diets in rumen excretes excessive nitrogen (N) through urine and feces in the environment...
November 8, 2017: Environmental Science and Pollution Research International
Jessika Füssel, Sebastian Lücker, Pelin Yilmaz, Boris Nowka, Maartje A H J van Kessel, Patric Bourceau, Philipp F Hach, Sten Littmann, Jasmine Berg, Eva Spieck, Holger Daims, Marcel M M Kuypers, Phyllis Lam
Nitrite-oxidizing bacteria (NOB) have conventionally been regarded as a highly specialized functional group responsible for the production of nitrate in the environment. However, recent culture-based studies suggest that they have the capacity to lead alternative lifestyles, but direct environmental evidence for the contribution of marine nitrite oxidizers to other processes has been lacking to date. We report on the alternative biogeochemical functions, worldwide distribution, and sometimes high abundance of the marine NOB Nitrococcus...
November 2017: Science Advances
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