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Denitrifying bacteria

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
Sai Xu, Wenjing Lu, Farooq Mustafa Muhammad, Yanting Liu, Hanwen Guo, Ruihong Meng, Hongtao Wang
The denitrifying anaerobic methane oxidation is an ecologically important process for reducing the potential methane emission into the atmosphere. The responsible bacterium for this process was Candidatus Methylomirabilis oxyfera belonging to the bacterial phylum of NC10. In this study, a new pair of primers targeting all the five groups of NC10 bacteria was designed to amplify NC10 bacteria from different environmental niches. The results showed that the group A was the dominant NC10 phylum bacteria from the sludges and food waste digestate while in paddy soil samples, group A and group B had nearly the same proportion...
March 2018: Journal of Environmental Sciences (China)
Heejung Kim, Dugin Kaown, Bernhard Mayer, Jin-Yong Lee, Kang-Kun Lee
Hyporheic zones are considered hot spots for numerically vast and phylogenetically diverse microbial communities. However, biogeochemical effects of hyporheic zones have rarely been investigated in detail because of the difficulty in accurately measuring denitrification in these zones. To date, little is known about the hydroecology of hyporheic zones. The effect of changes in hydraulic conditions on the community variations of indigenous microorganisms and water quality was examined based on the depth of the hyporheic zone...
March 12, 2018: Science of the Total Environment
Alejandro Gonzalez-Martinez, Alejandro Margareto, Alejandro Rodriguez-Sanchez, Chiara Pesciaroli, Silvia Diaz-Cruz, Damia Barcelo, Riku Vahala
The emergence and spread of antibiotics resistance in wastewater treatment systems have been pointed as a major environmental health problem. Nevertheless, research about adaptation and antibiotics resistance gain in wastewater treatment systems subjected to antibiotics has not been successfully developed considering bioreactor performance, microbial community dynamics and microbial activity dynamics at the same time. To observe this in autotrophic nitrogen removal systems, a partial-nitritation biofilter was subjected to a continuous loading of antibiotics mix of azithromycin, norfloxacin, trimethoprim, and sulfamethoxazole...
2018: Frontiers in Microbiology
Luyara de Almeida Fernandes, Alyne Duarte Pereira, Cíntia Dutra Leal, Russell Davenport, David Werner, Cesar Rossas Mota Filho, Thiago Bressani-Ribeiro, Carlos Augusto de Lemos Chernicharo, Juliana Calabria de Araújo
The effects of temperature reduction (from 35 °C to 20 °C) on nitrogen removal performance and microbial diversity of an anammox sequencing batch reactor were evaluated. The reactor was fed for 148 days with anaerobically pretreated municipal wastewater amended with nitrite. On average, removal efficiencies of ammonium and nitrite were high (96%) during the enrichment period and phases 1 (at 35 °C) and 2 (at 25 °C), and slightly decreased (to 90%) when the reactor was operated at 20 °C. Deep sequencing analysis revealed that microbial community structure changed with temperature decrease...
February 23, 2018: Bioresource Technology
Guangsheng Qian, Linlin Ye, Liang Li, Xiaomin Hu, Binhui Jiang, Xin Zhao
This study proposed a periodic reversal bio-electrocoagulation system (PRBES) with Fe-C electrodes and three other control systems and explored their denitrification mechanism. The experimental results illustrated that iron ions contributed to increasing biomass and denitrifying bacteria and that the electric field may enhance the nitrogen transfer rate and enzyme activities. The dominant bacterial genera in the four systems were the Enterobacter (32.75%), Thauera (9.29%), Paracoccus (8.54%), Hyphomicrobium (5...
February 27, 2018: Bioresource Technology
Songqi Liu, Chao Wang, Jun Hou, Peifang Wang, Lingzhan Miao, Xiulei Fan, Guoxiang You, Yi Xu
The widespread use of commercial silver nanoparticles (Ag NPs) inevitably results in their increased release into natural waters and subsequent deposition in sediments, requiring the environmental impact of such deposition to be closely investigated. Hence, the effects of Ag NPs, polyvinylpyrrolidone (PVP)-Ag NPs, and sliver sulfide nanoparticles (Ag2 S NPs) on denitrification-induced gas production (N2 O and15 N-N2 ), and denitrifying microbes in freshwater sediments were investigated. Slurry experiments (8 h) combined with a15 NO3 - addition technique were performed to determine the gaseous production...
March 8, 2018: Water Research
(no author information available yet)
The nitritation-anammox process is an efficient and cost-effective approach for biological nitrogen removal, but its application in treating mainstream wastewater remains a great challenge. Mainstream nitritation-anammox processes could create opportunities for achieving energy self-sufficient or energy-generating wastewater treatment plants. Significant advancements have been achieved via pilot- and full-scale trials to overcome the major obstacles under mainstream conditions, such as repression of nitrite-oxidizing bacteria, limiting the overgrowth of denitrifiers, and effective selection and retention of ammonia-oxidizing bacteria and anammox bacteria...
March 8, 2018: Water Environment Research: a Research Publication of the Water Environment Federation
Benjamin J Thwaites, Ben van den Akker, Petra J Reeve, Michael D Short, Nirmala Dinesh, Juan Pablo Alvarez-Gaitan, Richard Stuetz
The successful development of aerobic granular sludge (AGS) for secondary wastewater treatment has been linked to a dedicated anaerobic feeding phase, which enables key microbes such as poly-phosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms to gain a competitive advantage over floc-forming organisms. The application of AGS to treat high-saline sewage and its subsequent impacts on microbial ecology, however, are less well understood. In this study, the impacts of high-saline sewage on AGS development, performance and ecology were investigated using molecular microbiology methods...
February 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
Guangzhi Wang, Rui Chen, Likun Huang, Hemeng Ma, Deying Mu, Qingliang Zhao
An aerobic moving bed biofilm reactor (MBBR) was applied to treat landfill leachate generated from a domestic waste incineration plant. Pollutant removal efficiency of this reactor under stable operating condition was studied. The biomass, bacteria species, and microbial metabolism in this reactor were investigated. These results showed that the average removal efficiency of chemical oxygen demand (COD) and ammonia nitrogen in the aerobic MBBR achieved 64% and 97% in the optimum conditions, respectively. The three-dimensional fluorescence spectrum revealed that the content of soluble microbial byproducts from extracellular polymeric substances extraction in suspended sludge was much higher than that on biofilm, and the types of pollutants were various in different regions of the reactor...
February 2018: Water Science and Technology: a Journal of the International Association on Water Pollution Research
V D Litskas, X N Karamanlis, S P Prousali, D S Koveos
The antibiotic amoxicillin (AMX) is globally important for human and animal health. Although AMX is considered as a threat for the aquatic and terrestrial environment, limited data are present for its toxicity against key species such as denitrifying bacteria in soil, earthworms and plants. In the present research, the OECD protocols for environmental risk assessment were applied to study AMX acute toxicity, at nominal concentrations, close to the environmentally relevant, in soil bacteria responsible for nitrogen cycling, in the earthworm species Eisenia fetida and six plant species...
February 26, 2018: Bulletin of Environmental Contamination and Toxicology
Noriko A Cassman, Késia S Lourenço, Janaína B do Carmo, Heitor Cantarella, Eiko E Kuramae
Background: The production of 1 L of ethanol from sugarcane generates up to 12 L of vinasse, which is a liquid waste containing an as-yet uncharacterized microbial assemblage. Most vinasse is destined for use as a fertilizer on the sugarcane fields because of the high organic and K content; however, increased N2 O emissions have been observed when vinasse is co-applied with inorganic N fertilizers. Here we aimed to characterize the microbial assemblage of vinasse to determine the gene potential of vinasse microbes for contributing to negative environmental effects during fertirrigation and/or to the obstruction of bioethanol fermentation...
2018: Biotechnology for Biofuels
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
Hang Liu, Yongkui Yang, Huifang Sun, Lin Zhao, Yu Liu
The presence of antibiotics in wastewater has raised serious concerns about its potential impacts on biological nitrogen and phosphorus (N&P) removal. This study investigated the long-term process performance and microbial structures in response to tetracycline in the enhanced N&P removal process. Results showed that trace tetracycline (20 and 50 μg/L) had no obvious effect on the N&P removal, while the relative abundances of Nitrospira and poly-phosphate accumulating organisms (PAOs) were found to increase...
February 13, 2018: Bioresource Technology
A Castellano-Hinojosa, P Maza-Márquez, Y Melero-Rubio, J González-López, B Rodelas
Ammonia-oxidizing bacteria (AOB), ammonia oxidizing archaea (AOA) and N2 O-reducing denitrifiers were measured by quantitative real-time PCR (qPCR) in activated sludge samples from four full-scale wastewater treatment plants (WWTPs) in South Spain, and their abundances were linked to the generation of N2 O in the samples using multivariate analysis (Non-metric multidimensional scaling, MDS, and BIO-ENV). The average abundances of AOA remained in similar orders of magnitude in all WWTPs (106 copies amoA/L activated sludge mixed liquor), while significant differences were detected for AOB (105 -109 copies amoA/L) and N2 O-reducers (107 -1010 copies nosZ/L)...
February 19, 2018: Chemosphere
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
Monica Conthe, Lea Wittorf, J Gijs Kuenen, Robbert Kleerebezem, Sara Hallin, Mark C M van Loosdrecht
Nitrous oxide (N2 O) reducing microorganisms may be key in the mitigation of N2 O emissions from managed ecosystems. However, there is still no clear understanding of the physiological and bioenergetic implications of microorganisms possessing either of the two N2 O reductase genes (nosZ), clade I and the more recently described clade II type nosZ. It has been suggested that organisms with nosZ clade II have higher growth yields and a lower affinity constant (Ks ) for N2 O. We compared N2 O reducing communities with different nosZI/nosZII ratios selected in chemostat enrichment cultures, inoculated with activated sludge, fed with N2 O as a sole electron acceptor and growth limiting factor, and acetate as electron donor...
February 19, 2018: Environmental Microbiology Reports
Florian Reverey, Lars Ganzert, Gunnar Lischeid, Andreas Ulrich, Katrin Premke, Hans-Peter Grossart
Understanding interrelations between an environment's hydrological past and its current biogeochemistry is necessary for the assessment of biogeochemical and microbial responses to changing hydrological conditions. The question how previous dry-wet events determine the contemporary microbial and biogeochemical state is addressed in this study. Therefore, sediments exposed to the atmosphere of areas with a different hydrological past within one kettle hole, i.e. (1) the predominantly inundated pond center, (2) the pond margin frequently desiccated for longer periods and (3) an intermediate zone, were incubated with the same rewetting treatment...
February 2, 2018: Science of the Total Environment
Yong-Ze Lu, Liang Fu, Na Li, Jing Ding, Ya-Nan Bai, Petros Samaras, Raymond Jianxiong Zeng
Coupling of anaerobic ammonium oxidation (Anammox) with denitrifying anaerobic methane oxidation (DAMO) is a sustainable pathway for nitrogen removal and reducing methane emissions from wastewater treatment processes. However, studies on the competitive relation between Anammox bacteria and DAMO bacteria are limited. Here, we investigated the effects of variations in the contents of trace element iron on Anammox and DAMO microorganisms. The short-term results indicated that optimal concentrations of iron, which obviously stimulated the activity of Amammox bacteria, DAMO bacteria and DAMO archaea, were 80, 20, and 80 μM, respectively...
February 1, 2018: Chemosphere
Monica Conthe, Lea Wittorf, J Gijs Kuenen, Robbert Kleerebezem, Mark C M van Loosdrecht, Sara Hallin
Reduction of the greenhouse gas N2O to N2 is a trait among denitrifying and non-denitrifying microorganisms having an N2O reductase, encoded by nosZ. The nosZ phylogeny has two major clades, I and II, and physiological differences among organisms within the clades may affect N2O emissions from ecosystems. To increase our understanding of the ecophysiology of N2O reducers, we determined the thermodynamic growth efficiency of N2O reduction and the selection of N2O reducers under N2O- or acetate-limiting conditions in a continuous culture enriched from a natural community with N2O as electron acceptor and acetate as electron donor...
February 7, 2018: ISME Journal
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