scholarly journals Meta-azotomics of engineered wastewater treatment processes reveals differential contributions of established and novel models of N-cycling

2020 ◽  
Author(s):  
Mee-Rye Park ◽  
Medini K. Annavajhala ◽  
Kartik Chandran
Keyword(s):  
Wastewater Treatment ◽  
Ammonia Oxidation ◽  
Carbon Sources ◽  
N Cycling ◽  
Glycerol Metabolism ◽  
Ammonia Oxidizing Bacteria ◽  
Design And Optimization ◽  
Treatment Processes ◽  
Upstream Process ◽  
Biological Nitrogen

AbstractThe application of metagenomics and metatranscriptomics to field-scale engineered biological nitrogen removal (BNR) processes revealed a complex N-cycle network (the meta-azotome) therein in terms of microbial structure, potential and extant function. Autotrophic nitrification bore the imprint of well-documented Nitrosomonas and Nitrospira in most systems. However, in select BNR processes, complete ammonia oxidizing bacteria, comammox Nitrospira, unexpectedly contributed more substantially to ammonia oxidation than canonical ammonia oxidizing bacteria, based on metatranscriptomic profiling. Methylotrophic denitrification was distinctly active in methanol-fed reactors but not in glycerol-fed reactors. Interestingly, glycerol metabolism and N-reduction transcript signatures were uncoupled, possibly suggesting the role of other carbon sources in denitrification emanating from glycerol itself or from upstream process reactors. In sum, the meta-azotome of engineered BNR processes revealed both traditional and novel mechanisms of N-cycling. Similar interrogation approaches could potentially inform better design and optimization of wastewater treatment and engineered bioprocesses in general.

scholarly journals Overlooked nitrogen-cycling microorganisms in biological wastewater treatment

2021 ◽  
Vol 15 (6) ◽  
Author(s):  
Shaoyi Xu ◽  
Xiaolong Wu ◽  
Huijie Lu
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Cycling ◽  
Nitrogen Removal ◽  
Ammonia Oxidation ◽  
Current Knowledge ◽  
N Cycling ◽  
Anammox Bacteria ◽  
Kinetic Properties ◽  
Ammonia Oxidizing Bacteria ◽  
Removal Processes

AbstractNitrogen-cycling microorganisms play key roles at the intersection of microbiology and wastewater engineering. In addition to the well-studied ammonia oxidizing bacteria, nitrite oxidizing bacteria, heterotrophic denitrifiers, and anammox bacteria, there are some other N-cycling microorganisms that are less abundant but functionally important in wastewater nitrogen removal. These microbes include, but not limited to ammonia oxidizing archaea (AOA), complete ammonia oxidation (comammox) bacteria, dissimilatory nitrate reduction to ammonia (DNRA) bacteria, and nitrate/nitrite-dependent anaerobic methane oxidizing (NOx-DAMO) microorganisms. In the past decade, the development of high-throughput molecular technologies has enabled the detection, quantification, and characterization of these minor populations. The aim of this review is therefore to synthesize the current knowledge on the distribution, ecological niche, and kinetic properties of these “overlooked” N-cycling microbes at wastewater treatment plants. Their potential applications in novel wastewater nitrogen removal processes are also discussed. A comprehensive understanding of these overlooked N-cycling microbes from microbiology, ecology, and engineering perspectives will facilitate the design and operation of more efficient and sustainable biological nitrogen removal processes.

Indole degrading of ammonia oxidizing bacteria isolated from swine wastewater treatment system

2009 ◽  
Vol 59 (12) ◽  
pp. 2405-2410 ◽  
Author(s):  
Ping Li ◽  
Lei Tong ◽  
Kun Liu ◽  
Yanhong Wang ◽  
Yanxin Wang
Keyword(s):  
Wastewater Treatment ◽  
Biochemical Analysis ◽  
Ammonia Oxidation ◽  
Treatment System ◽  
Swine Wastewater ◽  
Ammonia Oxidizing Bacteria ◽  
16S Rdna Gene ◽  
Wastewater Treatment System ◽  
Nitrate And Nitrite ◽  
Physiological And Biochemical

Three new strains named LPA11, LPB11 and LPC24 were isolated to investigate the patterns of indole degradation and ammonia oxidation in swine wastewater from different parts of a swine wastewater treatment system by the direct spreading plate method. These three isolates were all identified as Pseudomonas putida based on 16S-rDNA gene sequences, main physiological and biochemical analysis. They were capable of decomposing 1.0 mM indole completely in 10, 16 and 18 days respectively. According to the results of HPLC and GC/MS, the possible pathway for the degradation was via oxindole, isatin and anthranilic acid. The three bacteria were capable of oxidizing ammonia, and the strains LPA11 and LPC24 were capable of effectively reducing nitrate and nitrite.

scholarly journals Low-Dissolved-Oxygen Nitrifying Systems Exploit Ammonia-Oxidizing Bacteria with Unusually High Yields

2011 ◽  
Vol 77 (21) ◽  
pp. 7787-7796 ◽  
Author(s):  
Micol Bellucci ◽  
Irina D. Ofiţeru ◽  
David W. Graham ◽  
Ian M. Head ◽  
Thomas P. Curtis
Keyword(s):  
Wastewater Treatment ◽  
Dissolved Oxygen ◽  
Ammonia Oxidation ◽  
Rrna Gene ◽  
Airflow Rate ◽  
Ammonia Oxidizing Bacteria ◽  
Oxidation Rates ◽  
Operational Costs ◽  
Complete Nitrification ◽  
Low Do

ABSTRACTIn wastewater treatment plants, nitrifying systems are usually operated with elevated levels of aeration to avoid nitrification failures. This approach contributes significantly to operational costs and the carbon footprint of nitrifying wastewater treatment processes. In this study, we tested the effect of aeration rate on nitrification by correlating ammonia oxidation rates with the structure of the ammonia-oxidizing bacterial (AOB) community and AOB abundance in four parallel continuous-flow reactors operated for 43 days. Two of the reactors were supplied with a constant airflow rate of 0.1 liter/min, while in the other two units the airflow rate was fixed at 4 liters/min. Complete nitrification was achieved in all configurations, though the dissolved oxygen (DO) concentration was only 0.5 ± 0.3 mg/liter in the low-aeration units. The data suggest that efficient performance in the low-DO units resulted from elevated AOB levels in the reactors and/or putative development of a mixotrophic AOB community. Denaturing gel electrophoresis and cloning of AOB 16S rRNA gene fragments followed by sequencing revealed that the AOB community in the low-DO systems was a subset of the community in the high-DO systems. However, in both configurations the dominant species belonged to theNitrosomonas oligotrophalineage. Overall, the results demonstrated that complete nitrification can be achieved at low aeration in lab-scale reactors. If these findings could be extended to full-scale plants, it would be possible to minimize the operational costs and greenhouse gas emissions without risk of nitrification failure.

scholarly journals Nitrification mainly driven by ammonia-oxidizing bacteria and nitrite-oxidizing bacteria in an anammox-inoculated wastewater treatment system

AMB Express ◽  
2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jing Lu ◽  
Yiguo Hong ◽  
Ying Wei ◽  
Ji-Dong Gu ◽  
Jiapeng Wu ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Nitrogen Removal ◽  
High Throughput Sequencing ◽  
High Efficiency ◽  
Ammonia Oxidation ◽  
Ammonia Oxidizing Bacteria ◽  
Ammonium Oxidation ◽  
Strong Activity ◽  
Nitrite Oxidizing Bacteria

AbstractAnaerobic ammonium oxidation (anammox) process has been acknowledged as an environmentally friendly and time-saving technique capable of achieving efficient nitrogen removal. However, the community of nitrification process in anammox-inoculated wastewater treatment plants (WWTPs) has not been elucidated. In this study, ammonia oxidation (AO) and nitrite oxidation (NO) rates were analyzed with the incubation of activated sludge from Xinfeng WWTPs (Taiwan, China), and the community composition of nitrification communities were investigated by high-throughput sequencing. Results showed that both AO and NO had strong activity in the activated sludge. The average rates of AO and NO in sample A were 6.51 µmol L−1 h−1 and 6.52 µmol L−1 h−1, respectively, while the rates in sample B were 14.48 µmol L−1 h−1 and 14.59 µmol L−1 h−1, respectively. The abundance of the nitrite-oxidizing bacteria (NOB) Nitrospira was 0.89–4.95 × 1011 copies/g in both samples A and B, the abundance of ammonia-oxidizing bacteria (AOB) was 1.01–9.74 × 109 copies/g. In contrast, the abundance of ammonia-oxidizing archaea (AOA) was much lower than AOB, only with 1.28–1.53 × 105 copies/g in samples A and B. The AOA community was dominated by Nitrosotenuis, Nitrosocosmicus, and Nitrososphaera, while the AOB community mainly consisted of Nitrosomonas and Nitrosococcus. The dominant species of Nitrospira were Candidatus Nitrospira defluvii, Candidatus Nitrospira Ecomare2 and Nitrospira inopinata. In summary, the strong nitrification activity was mainly catalyzed by AOB and Nitrospira, maintaining high efficiency in nitrogen removal in the anammox-inoculated WWTPs by providing the substrates required for denitrification and anammox processes.

scholarly journals High functional diversity among Nitrospira populations that dominate rotating biological contactor microbial communities in a municipal wastewater treatment plant

2019 ◽  
Author(s):  
Emilie Spasov ◽  
Jackson M. Tsuji ◽  
Laura A. Hug ◽  
Andrew C. Doxey ◽  
Laura A. Sauder ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Municipal Wastewater ◽  
Ammonia Oxidation ◽  
Treatment Plant ◽  
16S Rrna Gene Sequencing ◽  
Model Systems ◽  
Rrna Gene ◽  
Ammonia Oxidizing Bacteria ◽  
Municipal Wastewater Treatment ◽  
Nitrite Oxidizers

AbstractNitrification, the oxidation of ammonia to nitrate via nitrite, is an important process in municipal wastewater treatment plants (WWTPs). Members of the Nitrospira genus that contribute to complete ammonia oxidation (comammox) have only recently been discovered and their relevance to engineered water treatment systems is poorly understood. This study investigated distributions of Nitrospira, ammonia-oxidizing archaea (AOA), and ammonia-oxidizing bacteria (AOB) in biofilm samples collected from tertiary rotating biological contactors (RBCs) of a municipal WWTP in Guelph, Ontario, Canada. Using quantitative PCR (qPCR), 16S rRNA gene sequencing, and metagenomics, our results demonstrate that Nitrospira species strongly dominate RBC biofilm samples and that comammox Nitrospira outnumber all other nitrifiers. Genome bins recovered from assembled metagenomes reveal multiple populations of comammox Nitrospira with distinct spatial and temporal distributions, including several taxa that are distinct from previously characterized Nitrospira members. Diverse functional profiles imply a high level of niche heterogeneity among comammox Nitrospira, in contrast to the sole detected AOA representative that was previously cultivated and characterized from the same RBC biofilm. Our metagenome bins also reveal two cyanase-encoding populations of comammox Nitrospira, suggesting an ability to degrade cyanate, which has not been shown previously for Nitrospira that are not strict nitrite oxidizers. This study demonstrates the importance of RBCs as model systems for continued investigation of environmental factors that control the distributions and activities of AOB, AOA, comammox Nitrospira, and other nitrite oxidizers.

Detection and quantification of expression of amoA by competitive reverse transcription-PCR

2002 ◽  
Vol 46 (1-2) ◽  
pp. 281-288 ◽  
Author(s):  
Y. Ebie ◽  
H. Miura ◽  
N. Noda ◽  
M. Matsumura ◽  
S. Tsuneda ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Ammonia Oxidation ◽  
Dry Weight ◽  
Ammonia Oxidizing Bacteria ◽  
Rt Pcr ◽  
Oxidation Activity ◽  
Reverse Transcription Pcr ◽  
A Subunit ◽  
Bacterial Aggregates ◽  
Biological Nitrogen

Ammonia oxidation by chemolithoautotrophic ammonia-oxidizing bacteria is an important step in the biological nitrogen removal process. The first conversion step, the oxidation of ammonia to hydroxylamine is catalyzed by ammonia monooxygenase (AMO). To investigate the activity of ammonia oxidation, mRNA (designated as amoA) encoding a subunit of AMO was quantified by competitive reverse transcription (RT)-PCR. As a result, it was possible to detect and quantify amoA expression in cultured Nitrosomonas europaea and even complex microbial communities such as nitrifying bacterial aggregates by competitive RT-PCR. It was estimated that amoA concentration in cultured N. europaea was 2.3 × 108 copies·ml−1. Additionally, it was calculated that the copy number of amoA in nitrifying bacterial aggregates was 1.0 × 1012 copies·ml−1 (5.1 × 1010 copies·mg−1-dry weight). On the other hand, amoA expression in the natural activated sludge in a household Gappei-Johkaso was undetectable, whereas 16S rRNA of ammonia-oxidizing bacteria was detected by RT-PCR. Then, four days cultivation of this sludge in inorganic artificial wastewater resulted in increasing amoA expression to a quantifiable amount by competitive RT-PCR. In conclusion, the competitive RT-PCR was effective to investigate the expression of amoA as an indicator of ammonia oxidation activity by autotrophic ammonia-oxidizing bacteria.

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