scholarly journals Sulfide-Induced Dissimilatory Nitrate Reduction to Ammonium Supports Anaerobic Ammonium Oxidation (Anammox) in an Open-Water Unit Process Wetland

2017 ◽  
Vol 83 (15) ◽  
Author(s):  
Zackary L. Jones ◽  
Justin T. Jasper ◽  
David L. Sedlak ◽  
Jonathan O. Sharp
Keyword(s):  
Nitrate Reduction ◽  
Municipal Wastewater ◽  
Open Water ◽  
Fold Increase ◽  
Rrna Gene ◽  
Ammonium Oxidation ◽  
Content Type ◽  
Unit Process ◽  
Dissimilatory Nitrate Reduction ◽  
Pcr Targeting

ABSTRACT Open-water unit process wetlands host a benthic diatomaceous and bacterial assemblage capable of nitrate removal from treated municipal wastewater with unexpected contributions from anammox processes. In exploring mechanistic drivers of anammox, 16S rRNA gene sequencing profiles of the biomat revealed significant microbial community shifts along the flow path and with depth. Notably, there was an increasing abundance of sulfate reducers (Desulfococcus and other Deltaproteobacteria) and anammox microorganisms (Brocadiaceae) with depth. Pore water profiles demonstrated that nitrate and sulfate concentrations exhibited a commensurate decrease with biomat depth accompanied by the accumulation of ammonium. Quantitative PCR targeting the anammox hydrazine synthase gene, hzsA, revealed a 3-fold increase in abundance with biomat depth as well as a 2-fold increase in the sulfate reductase gene, dsrA. These microbial and geochemical trends were most pronounced in proximity to the influent region of the wetland where the biomat was thickest and influent nitrate concentrations were highest. While direct genetic queries for dissimilatory nitrate reduction to ammonium (DNRA) microorganisms proved unsuccessful, an increasing depth-dependent dominance of Gammaproteobacteria and diatoms that have previously been functionally linked to DNRA was observed. To further explore this potential, a series of microcosms containing field-derived biomat material confirmed the ability of the community to produce sulfide and reduce nitrate; however, significant ammonium production was observed only in the presence of hydrogen sulfide. Collectively, these results suggest that biogenic sulfide induces DNRA, which in turn can explain the requisite coproduction of ammonium and nitrite from nitrified effluent necessary to sustain the anammox community. IMPORTANCE This study aims to increase understanding of why and how anammox is occurring in an engineered wetland with limited exogenous contributions of ammonium and nitrite. In doing so, the study has implications for how geochemical parameters could potentially be leveraged to impact nutrient cycling and attenuation during the operation of treatment wetlands. The work also contributes to ongoing discussions about biogeochemical signatures surrounding anammox processes and enhances our understanding of the contributions of anammox processes in freshwater environments.

scholarly journals Lachnospiraceae and Bacteroidales Alternative Fecal Indicators Reveal Chronic Human Sewage Contamination in an Urban Harbor

2011 ◽  
Vol 77 (19) ◽  
pp. 6972-6981 ◽  
Author(s):  
Ryan J. Newton ◽  
Jessica L. VandeWalle ◽  
Mark A. Borchardt ◽  
Marc H. Gorelick ◽  
Sandra L. McLellan
Keyword(s):  
Sequence Analysis ◽  
Genetic Marker ◽  
Microbial Community Composition ◽  
Fold Increase ◽  
Fecal Pollution ◽  
Plate Count ◽  
Rrna Gene ◽  
Fecal Indicators ◽  
Fecal Indicator ◽  
Content Type

ABSTRACTThe complexity of fecal microbial communities and overlap among human and other animal sources have made it difficult to identify source-specific fecal indicator bacteria. However, the advent of next-generation sequencing technologies now provides increased sequencing power to resolve microbial community composition within and among environments. These data can be mined for information on source-specific phylotypes and/or assemblages of phylotypes (i.e., microbial signatures). We report the development of a new genetic marker for human fecal contamination identified through microbial pyrotag sequence analysis of the V6 region of the 16S rRNA gene. Sequence analysis of 37 sewage samples and comparison with database sequences revealed a human-associated phylotype within theLachnospiraceaefamily, which was closely related to the genusBlautia. This phylotype, termed Lachno2, was on average the second most abundant fecal bacterial phylotype in sewage influent samples from Milwaukee, WI. We developed a quantitative PCR (qPCR) assay for Lachno2 and used it along with the qPCR-based assays for humanBacteroidales(based on the HF183 genetic marker), totalBacteroidalesspp., and enterococci and the conventionalEscherichia coliand enterococci plate count assays to examine the prevalence of fecal and human fecal pollution in Milwaukee's harbor. Both the conventional fecal indicators and the human-associated indicators revealed chronic fecal pollution in the harbor, with significant increases following heavy rain events and combined sewer overflows. The two human-associated genetic marker abundances were tightly correlated in the harbor, a strong indication they target the same source (i.e., human sewage). Human adenoviruses were routinely detected under all conditions in the harbor, and the probability of their occurrence increased by 154% for every 10-fold increase in the human indicator concentration. Both Lachno2 and humanBacteroidalesincreased specificity to detect sewage compared to general indicators, and the relationship to a human pathogen group suggests that the use of these alternative indicators will improve assessments for human health risks in urban waters.

scholarly journals Bacteria from the Genus Arcobacter Are Abundant in Effluent from Wastewater Treatment Plants

2020 ◽  
Vol 86 (9) ◽  
Author(s):  
Jannie Munk Kristensen ◽  
Marta Nierychlo ◽  
Mads Albertsen ◽  
Per Halkjær Nielsen
Keyword(s):  
Wastewater Treatment ◽  
Pathogenic Bacteria ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Amplicon Sequencing ◽  
Rrna Gene ◽  
Content Type ◽  
Effluent Quality ◽  
Culture Independent ◽  
Influent Wastewater

ABSTRACT Pathogenic bacteria in wastewater are generally considered to be efficiently removed in biological wastewater treatment plants. This understanding is almost solely based on culture-based control measures, and here we show, by applying culture-independent methods, that the removal of species in the genus Arcobacter was less effective than for many other abundant genera in the influent wastewater. Arcobacter was one of the most abundant genera in influent wastewater at 14 municipal wastewater treatment plants and was also abundant in the “clean” effluent from all the plants, reaching up to 30% of all bacteria as analyzed by 16S rRNA gene amplicon sequencing. Metagenomic analyses, culturing, genome sequencing of Arcobacter isolates, and visualization by fluorescent in situ hybridization (FISH) confirmed the presence of the human-pathogenic Arcobacter cryaerophilus and A. butzleri in both influent and effluent. The main reason for the high relative abundance in the effluent was probably that Arcobacter cells, compared to those of other abundant genera in the influent, did not flocculate and attach well to the activated sludge flocs, leaving a relatively large fraction dispersed in the water phase. The study shows there is an urgent need for new standardized culture-independent measurements of pathogens in effluent wastewaters, e.g., amplicon sequencing, and an investigation of the problem on a global scale to quantify the risk for humans and livestock. IMPORTANCE The genus Arcobacter was unexpectedly abundant in the effluent from 14 Danish wastewater treatment plants treating municipal wastewater, and the species included the human-pathogenic A. cryaerophilus and A. butzleri. Recent studies have shown that Arcobacter is common in wastewater worldwide, so the study indicates that discharge of members of the genus Arcobacter may be a global problem, and further studies are needed to quantify the risk and potentially minimize the discharge. The study also shows that culture-based analyses are insufficient for proper effluent quality control, and new standardized culture-independent measurements of effluent quality encompassing most pathogens should be considered.

scholarly journals Environmental Controls of Oyster-PathogenicVibriospp. in Oregon Estuaries and a Shellfish Hatchery

2018 ◽  
Vol 84 (9) ◽  
Author(s):  
Mary R. Gradoville ◽  
Byron C. Crump ◽  
Claudia C. Häse ◽  
Angelicque E. White
Keyword(s):  
Coastal Waters ◽  
Multiple Stressors ◽  
Fold Increase ◽  
16S Rrna Gene Sequencing ◽  
Digital Pcr ◽  
Rrna Gene ◽  
Local Growth ◽  
Content Type ◽  
Environmental Controls ◽  
Planktonic State

ABSTRACTVibriospp. have been a persistent concern for coastal bivalve hatcheries, which are vulnerable to environmental pathogens in the seawater used for rearing larvae, yet the biogeochemical drivers of oyster-pathogenicVibriospp. in their planktonic state are poorly understood. Here, we present data tracking oyster-pathogenicVibriobacteria in Netarts Bay and Yaquina Bay in Oregon, USA, as well as in adjacent coastal waters and a local shellfish hatchery, through the 2015 upwelling season.Vibriopopulations were quantified using a culture-independent approach of high-throughputVibrio-specific 16S rRNA gene sequencing paired with droplet digital PCR, and abundances were analyzed in the context of local biogeochemistry. The most abundant putative pathogen in our samples wasVibrio coralliilyticus. Environmental concentrations of totalVibriospp. andV. coralliilyticuswere highest in Netarts Bay sediment samples and higher in seawater from Netarts Bay than from nearshore coastal waters or Yaquina Bay. In Netarts Bay, the highestV. coralliilyticusconcentrations were observed during low tide, and abundances increased throughout the summer. We hypothesize that the warm shallow waters in estuarine mudflats facilitate the local growth of theV. coralliilyticuspathogen. Samples from larval oyster tanks in Whiskey Creek Shellfish Hatchery, which uses seawater pumped directly from Netarts Bay, contained significantly lower totalVibriospecies concentrations, but roughly similarV. coralliilyticusconcentrations, than did the bay water, resulting in a 30-fold increase in the relative abundance of theV. coralliilyticuspathogen in hatchery tanks. This suggests that theV. coralliilyticuspathogen is able to grow or persist under hatchery conditions.IMPORTANCEIt has been argued that oyster-pathogenicVibriospp. have contributed to recent mortality events in U.S. shellfish hatcheries (R. A. Elston, H. Hasegawa, K. L. Humphrey, I. K. Polyak, and C. Häse, Dis Aquat Organ 82:119–134, 2008,https://doi.org/10.3354/dao01982); however, these events are often sporadic and unpredictable. The success of hatcheries is critically linked to the chemical and biological composition of inflowing seawater resources; thus, it is pertinent to understand the biogeochemical drivers of oyster-pathogenicVibriospp. in their planktonic state. Here, we show that Netarts Bay, the location of a local hatchery, is enriched in oyster-pathogenicV. coralliilyticuscompared to coastal seawater, and we hypothesize that conditions in tidal flats promote the local growth of this pathogen. Furthermore,V. coralliilyticusappears to persist in seawater pumped into the local hatchery. These results improve our understanding of the ecology and environmental controls of theV. coralliilyticuspathogen and could be used to improve future aquaculture efforts, as multiple stressors impact hatchery success.

scholarly journals Denitrification, anaerobic ammonium oxidation, and dissimilatory nitrate reduction to ammonium in an East African Great Lake (Lake Kivu)

2017 ◽  
Vol 63 (2) ◽  
pp. 687-701 ◽  
Author(s):  
Fleur A. E. Roland ◽  
François Darchambeau ◽  
Alberto V. Borges ◽  
Cédric Morana ◽  
Loreto De Brabandere ◽  
...  
Keyword(s):  
Nitrate Reduction ◽  
Great Lake ◽  
Anaerobic Ammonium Oxidation ◽  
Ammonium Oxidation ◽  
East African ◽  
Dissimilatory Nitrate Reduction ◽  
Lake Kivu

scholarly journals Modification of Norfloxacin by a Microbacterium sp. Strain Isolated from a Wastewater Treatment Plant

2011 ◽  
Vol 77 (17) ◽  
pp. 6100-6108 ◽  
Author(s):  
Dae-Wi Kim ◽  
Thomas M. Heinze ◽  
Bong-Soo Kim ◽  
Laura K. Schnackenberg ◽  
Kellie A. Woodling ◽  
...  
Keyword(s):  
Amino Acids ◽  
Bacterial Strain ◽  
Municipal Wastewater ◽  
Enrichment Culture ◽  
Treatment Plant ◽  
Rrna Gene ◽  
Content Type ◽  
Development Of Resistance ◽  
Liquid Chromatography Tandem Mass ◽  
Plant Growth Promoting

ABSTRACTAntimicrobial residues found in municipal wastewater may increase selective pressure on microorganisms for development of resistance, but studies with mixed microbial cultures derived from wastewater have suggested that some bacteria are able to inactivate fluoroquinolones. Medium containingN-phenylpiperazine and inoculated with wastewater was used to enrich fluoroquinolone-modifying bacteria. One bacterial strain isolated from an enrichment culture was identified by 16S rRNA gene sequence analysis as aMicrobacteriumsp. similar to a plant growth-promoting bacterium,Microbacterium azadirachtae(99.70%), and a nematode pathogen, “M. nematophilum” (99.02%). During growth in medium with norfloxacin, this strain produced four metabolites, which were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and nuclear magnetic resonance (NMR) analyses as 8-hydroxynorfloxacin, 6-defluoro-6-hydroxynorfloxacin, desethylene norfloxacin, andN-acetylnorfloxacin. The production of the first three metabolites was enhanced by ascorbic acid and nitrate, but it was inhibited by phosphate, amino acids, mannitol, formate, and thiourea. In contrast,N-acetylnorfloxacin was most abundant in cultures supplemented with amino acids. This is the first report of defluorination and hydroxylation of a fluoroquinolone by an isolated bacterial strain. The results suggest that some bacteria may degrade fluoroquinolones in wastewater to metabolites with less antibacterial activity that could be subject to further degradation by other microorganisms.

scholarly journals Effects of Sulfamethoxazole and 2-Ethylhexyl-4-Methoxycinnamate on the Dissimilatory Nitrate Reduction Processes and N2O Release in Sediments in the Yarlung Zangbo River

2020 ◽  
Vol 17 (6) ◽  
pp. 1822 ◽  
Author(s):  
Huiping Xu ◽  
Guanghua Lu ◽  
Chenwang Xue
Keyword(s):  
High Altitude ◽  
Nitrate Reduction ◽  
River Sediments ◽  
Nitrogen Transformation ◽  
Emerging Pollutants ◽  
15N Tracer ◽  
Ammonium Oxidation ◽  
Reduction Processes ◽  
Dissimilatory Nitrate Reduction ◽  
Yarlung Zangbo River

The nitrogen pollution of rivers as a global environmental problem has received great attentions in recent years. The occurrence of emerging pollutants in high-altitude rivers will inevitably affect the dissimilatory nitrate reduction processes. In this study, sediment slurry experiments combined with 15N tracer techniques were conducted to investigate the influence of pharmaceutical and personal care products (alone and in combination) on denitrification and the anaerobic ammonium oxidation (anammox) process and the resulting N2O release in the sediments of the Yarlung Zangbo River. The results showed that the denitrification rates were inhibited by sulfamethoxazole (SMX) treatments (1–100 μg L−1) and the anammox rates decreased as the SMX concentrations increased, which may be due to the inhibitory effect of this antibiotic on nitrate reducing microbes. 2-Ethylhexyl-4-methoxycinnamate (EHMC) impacted nitrogen transformation mainly though the inhibition of the anammox processes. SMX and EHMC showed a superposition effect on the denitrification processes. The expression levels of the denitrifying functional genes nirS and nosZ were decreased and N2O release was stimulated due to the presence of SMX and/or EHMC in the sediments. To the best of our knowledge, this study is the first to report the effects of EHMC and its mixtures on the dissimilatory nitrate reduction processes and N2O releases in river sediments. Our results indicated that the widespread occurrence of emerging pollutants in high-altitude rivers may disturb the nitrogen transformation processes and increase the pressure of global warming.

scholarly journals Sensitive Quantification of Clostridium difficile Cells by Reverse Transcription-Quantitative PCR Targeting rRNA Molecules

2012 ◽  
Vol 78 (15) ◽  
pp. 5111-5118 ◽  
Author(s):  
Kazunori Matsuda ◽  
Hirokazu Tsuji ◽  
Takashi Asahara ◽  
Takuya Takahashi ◽  
Hiroyuki Kubota ◽  
...  
Keyword(s):  
Clostridium Difficile ◽  
Quantitative Pcr ◽  
Reverse Transcription ◽  
Care Facility ◽  
23S Rrna ◽  
Rrna Gene ◽  
Carriage Rate ◽  
Content Type ◽  
Reverse Transcription Quantitative Pcr ◽  
Pcr Targeting

ABSTRACTWe established a sensitive and accurate quantification system forClostridium difficilein human intestines, based on rRNA-targeted reverse transcription-quantitative PCR (RT-qPCR). We newly developed a species-specific primer set forC. difficiletargeting 23S rRNA gene sequences. Both the vegetative cells and the spores ofC. difficilein human feces were quantified by RT-qPCR, with a lower detection limit of 102.4cells/g of feces. In an analysis of the feces of residents (n= 83; age, 85 ± 8 years) and staff (n= 19; age, 36 ± 10 years) at a care facility for the elderly,C. difficilewas detected by RT-qPCR in 43% of the residents (average count, log104.0 ± 2.0 cells/g of feces) and 16% of the staff (average count, log102.2 ± 0.1 cells/g of feces); these rates were far higher than those detected by qPCR (residents, 19%; staff, 0%) or selective cultivation (residents, 18%; staff, 5%). Another analysis of healthy adults (n= 63; age, 41 ± 11 years) also revealed the significant carriage rate ofC. difficilein the intestines (detection rate, 13%; average count, log104.9 ± 1.2 cells/g of feces). From these results, it was suggested that rRNA-targeted RT-qPCR should be an effective tool for analyzing population levels ofC. difficilein the human intestine.

scholarly journals Stable Core Gut Microbiota across the Freshwater-to-Saltwater Transition for Farmed Atlantic Salmon

2017 ◽  
Vol 84 (2) ◽  
Author(s):  
Knut Rudi ◽  
Inga Leena Angell ◽  
Phillip B. Pope ◽  
Jon Olav Vik ◽  
Simen Rød Sandve ◽  
...  
Keyword(s):  
Atlantic Salmon ◽  
Gut Microbiota ◽  
Bacterial Species ◽  
Fold Increase ◽  
Aquatic Environments ◽  
Rrna Gene ◽  
Host Bacterium ◽  
Microbiota Composition ◽  
Content Type ◽  
Farmed Atlantic Salmon

ABSTRACT Gut microbiota associations through habitat transitions are fundamentally important yet poorly understood. One such habitat transition is the migration from freshwater to saltwater for anadromous fish, such as salmon. The aim of the current work was therefore to determine the freshwater-to-saltwater transition impact on the gut microbiota in farmed Atlantic salmon, with dietary interventions resembling freshwater and saltwater diets with respect to fatty acid composition. Using deep 16S rRNA gene sequencing and quantitative PCR, we found that the freshwater-to-saltwater transition had a major association with the microbiota composition and quantity, while diet did not show significant associations with the microbiota. In saltwater there was a 100-fold increase in bacterial quantity, with a relative increase of Firmicutes and a relative decrease of both Actinobacteria and Proteobacteria. Irrespective of an overall shift in microbiota composition from freshwater to saltwater, we identified three core clostridia and one Lactobacillus-affiliated phylotype with wide geographic distribution that were highly prevalent and co-occurring. Taken together, our results support the importance of the dominating bacteria in the salmon gut, with the freshwater microbiota being immature. Due to the low number of potentially host-associated bacterial species in the salmon gut, we believe that farmed salmon can represent an important model for future understanding of host-bacterium interactions in aquatic environments. IMPORTANCE Little is known about factors affecting the interindividual distribution of gut bacteria in aquatic environments. We have shown that there is a core of four highly prevalent and co-occurring bacteria irrespective of feed and freshwater-to-saltwater transition. The potential host interactions of the core bacteria, however, need to be elucidated further.

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