Article
Microbiology
Elizabeth A. McDaniel, Francisco Moya-Flores, Natalie Keene Beach, Pamela Y. Camejo, Ben O. Oyserman, Matthew Kizaric, Eng Hoe Khor, Daniel R. Noguera, Katherine D. McMahon
Summary: The study explored the gene expression patterns of coexisting Accumulibacter strains in a bioreactor system, identifying putative pathways and functions that may confer distinct functions to the strains. The research provides key functional insights into this biotechnologically significant microbial lineage and offers an approach for elucidating ecologically relevant functions based on gene expression patterns between closely related microbial populations.
Review
Environmental Sciences
Ruby Diaz, Brendan Mackey, Sreeni Chadalavada, Jyoti Kainthola, Phil Heck, Ramesh Goel
Summary: The article discusses the pollution of surface water by excess phosphorus and nitrogen, as well as the Enhanced Biological Phosphorus Removal (EBPR) based treatment as an economical and eco-friendly solution. Molecular tools targeting bacterial genomic DNA have helped reveal the identity of potential PAO and DPAO responsible for the success of EBPR, providing confidence to the global wastewater community for EBPR practices.
Article
Engineering, Environmental
Ali Elahinik, Maureen Haarsma, Ben Abbas, Martin Pabst, Dimitrios Xevgenos, Mark C. M. van Loosdrecht, Mario Pronk
Summary: This study describes the utilization of glycerol by aerobic granular sludge and enhanced biological phosphorus removal (EBPR) in a sequencing batch reactor. The results show that glycerol-containing wastewater can effectively be treated by the aerobic granular sludge process and that fermentative and polyphosphate accumulating organisms can form a food chain in glycerol-based EBPR processes.
Article
Environmental Sciences
Parnian Izadi, Parin Izadi, Ahmed Eldyasti
Summary: Recent research has demonstrated the adaptability of Biological Nutrient Removal systems to low dissolved oxygen levels, particularly in maintaining nitrogen oxidation processes. A gradual decrease in aeration levels can improve phosphorus removal efficiency, while instant decreases may adversely impact performance.
Review
Environmental Sciences
Parnian Izadi, Parin Izadi, Ahmed Eldyasti
Summary: Enhanced biological phosphorus removal (EBPR) is a promising technology for efficient and sustainable removal of phosphorus from wastewater, but insufficient removal in full-scale wastewater treatment plants is a common issue. In-depth understanding of biochemical pathways and metabolic models can help predict optimal operational conditions and assess potential future research directions to address knowledge gaps.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Engineering, Environmental
Varun N. Srinivasan, Guangyu Li, Dongqi Wang, Nicholas B. Tooker, Zihan Dai, Annalisa Onnis-Hayden, Charles Bott, Paul Dombrowski, Peter Schauer, Ameet Pinto, April Z. Gu
Summary: This study compared the microbial ecology of CAP between a side-stream EBPR and a conventional A2O EBPR process, revealing differences in microdiversity that likely contribute to the improved performance of S2EBPR. It also identified previously uncharacterized clades of CAP and demonstrated the temporally increasing predominance of certain CAP clades during the implementation of the S2EBPR configuration in full-scale EBPR systems.
Review
Environmental Sciences
Parnian Izadi, Mehran Andalib
Summary: Stringent discharge phosphorus limits and the need for very low effluent total phosphorus concentrations have posed challenges for phosphorus removal technologies. The significance of the Enhanced Biological Phosphorus Removal (EBPR) process has been overshadowed by design and operation limitations, which result from a lack of knowledge and understanding of fundamental mechanisms, design standards, and operational guidance. This paper critically reviews different perspectives on mainstream and side-stream EBPR processes, focusing on contrasting views on hydrolysis and fermentation rates, as well as anaerobic condition implementation and magnitude.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
M. Sarvajith, Y. Nancharaiah
Summary: This study found that the addition of GAC to AGS reactors can promote the enrichment of PAOs, shorten the start-up period for EBPR, and increase phosphorus removal efficiencies.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Taotao Lv, Dongqi Wang, Jiayao Hui, Wen Cheng, Hao Ai, Lu Qin, Mengbo Huang, Minquan Feng, Yufan Wu
Summary: In this study, the effect of the return activated sludge (RAS) diversion ratio on S2EBPR reactor was investigated. The results showed that the RAS diversion ratio of 8.0% resulted in the lowest effluent PO43--P concentration of 0.5 +/- 0.3 mg P/L. The results of microbial ecology analysis revealed that the optimized SRTSS would give a competitive advantage to polyphosphate accumulating organisms (PAOs) in the S2EBPR process.
ENVIRONMENTAL RESEARCH
(2023)
Article
Engineering, Environmental
Ali Reza Massoompour, Mohammad Raie, S. Mehdi Borghei, Lise Appels, Raf Dewil
Summary: This study demonstrates that the carrier material type affects the stoichiometry of anaerobic conversion and metabolism in cultures enriched with PAOs, leading to an increase in biological phosphorus removal performance. The novel carbon-based moving carrier (CBMC) showed higher biomass adhesion and a greater reliance on intracellularly stored polyphosphate, resulting in a dominance of PAO metabolism and enhanced phosphorus removal efficiency compared to the typical moving bed bioreactor carrier (MBBR).
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Engineering, Environmental
Srdana Kolakovic, Elisabete B. Freitas, Maria A. M. Reis, Gilda Carvalho, Adrian Oehmen
Summary: This study investigated the relationship between the diversity of Accumulibacter and EBPR performance, revealing that changes in the community structure and conditions of Accumulibacter under different operating conditions can influence the success or failure of EBPR operation.
Article
Environmental Sciences
Jieyu Chen, Jie Wang, Xiaoning Wang, Yabing Lv, Dapeng Li, Jie Hou, Xugang He
Summary: Cooperation between Phosphate and Glycogen Accumulating Organisms (PAOs and GAOs) in SNEDPR systems is crucial for nutrient removal. Regulating competition between PAOs and GAOs through operational mode adjustment is key to achieving desired nutrient removal performance in CW systems.
Article
Engineering, Environmental
Francesca Petriglieri, Jette F. Petersen, Miriam Peces, Marta Nierychlo, Kamilla Hansen, Cecilie E. Baastrand, Ulla Gro Nielsen, Kasper Reitzel, Per Halkjaer Nielsen
Summary: Phosphorus exists in different forms in activated sludge, including metal salt precipitates, extracellular polymeric substances, and bound into biomass. This study combines various methods to obtain a comprehensive P mass-balance of activated sludge from EBPR plants. Chemically bound P constitutes the largest proportion of total P, while poly-P is found in bacterial cells.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Biotechnology & Applied Microbiology
Parnian Izadi, Parin Izadi, Ahmed Eldyasti
Summary: The study found that dissolved oxygen levels greatly influence phosphorus removal performance, with high removal achieved at lower dissolved oxygen levels. Additionally, controlled aeration at low dissolved oxygen concentrations provided a selective advantage for phosphorus accumulating organisms (PAOs) over glycogen accumulating organisms (GAOs) in microbial competition.
BIOCHEMICAL ENGINEERING JOURNAL
(2021)
Article
Green & Sustainable Science & Technology
Shengqiang Hei, Hui Xu, Yanchen Liu, Biming Liu, Shuo Zhang, Xianzheng Zhu, Weichen Lin, Lu Chen, Haisha Jiang, Xianwei Cheng, Xiaolei Yong, Xiaoyi Wu, Xia Huang
Summary: Phosphorus removal from wastewater is crucial for limiting water eutrophication. This study focused on enhancing biological phosphorus removal (BPR) efficiency in real full-scale municipal wastewater treatment plants (WWTPs) through improved redox environment and reduced chemicals consumption. The results showed that the strategy successfully increased BPR contribution, reduced chemicals dosage, and enriched phosphate-accumulating organisms (PAO) in the treatment process.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Ecology
Burak Avci, Jakob Brandt, Dikla Nachmias, Natalie Elia, Mads Albertsen, Thijs J. G. Ettema, Andreas Schramm, Kasper Urup Kjeldsen
Summary: Asgard archaea are the closest prokaryotic relatives of eukaryotes, with their genomes encoding various eukaryotic signature proteins. Research has shown that these archaea may have separated DNA from ribosomal signals in their cells, suggesting potential compartmentalization or membrane invagination within the cells.
Article
Engineering, Environmental
Dorottya S. Wagner, Miriam Peces, Marta Nierychlo, Artur T. Mielczarek, Dines Thornberg, Per H. Nielsen
Summary: This study tested different mitigation strategies to reduce filamentous bulking in a full-scale water resource recovery facility. The settlement of activated sludge was not affected by any of the strategies, and detailed analyses revealed that the filamentous bacteria were mostly unaffected by the mitigation strategies. The study emphasizes the importance of long-term monitoring of microbial communities and the use of parallel reference treatment lines.
Review
Microbiology
Hans-Curt Flemming, Eric D. van Hullebusch, Thomas R. Neu, Per H. Nielsen, Thomas Seviour, Paul Stoodley, Jost Wingender, Stefan Wuertz
Summary: In this review, the authors revisit the understanding of the biofilm matrix and discuss the diversity of its components and the novel aspects of their functional interactions. The biofilm matrix plays a crucial role in stabilizing microbial cells and fulfilling various functions. It is dynamic and influenced by physico-chemical and biological interactions as well as environmental conditions.
NATURE REVIEWS MICROBIOLOGY
(2023)
Article
Ecology
Mantas Sereika, Francesca Petriglieri, Thomas Bygh Nymann Jensen, Artur Sannikov, Morten Hoppe, Per Halkjaer Nielsen, Ian P. G. Marshall, Andreas Schramm, Mads Albertsen
Summary: Cable bacteria are centimeter-long filamentous bacteria capable of long-distance electron transfer. They are currently classified into two candidate genera: Candidatus Electronema, found in freshwater, and Candidatus Electrothrix, found in saltwater. To address the lack of complete genomic information, researchers performed Nanopore long-read and Illumina short-read shotgun sequencing, resulting in the recovery of multiple cable bacteria genomes. Phylogenomic analysis classified two circular genomes as novel species: Ca. Electronema halotolerans and Ca. Electrothrix laxa. The discovery of Ca. Electronema halotolerans in brackish-water sediment suggests its evolutionary link between marine and freshwater cable bacteria lineages.
Article
Biochemical Research Methods
Tue Sparholt Jorgensen, Martin Schou Pedersen, Kai Blin, Franziska Kuntke, Henrik K. Salling, Rasmus L. Marvig, Thomas Y. Michaelsen, Mads Albertsen, Helene Larsen
Summary: SpikeSeq is a Sanger sequencing-based method for detecting Variants of Concern (VOC) and key mutations of the novel coronavirus. It is simple, cost-effective, and can be implemented in any diagnostic lab.
JOURNAL OF VIROLOGICAL METHODS
(2023)
Article
Engineering, Environmental
Morten Kam Dahl Dueholm, Maaike Besteman, Emil Juel Zeuner, Marie Riisgaard-Jensen, Morten Eneberg Nielsen, Sofie Zacho Vestergaard, Soren Heidelbach, Nicolai Sundgaard Bekker, Per Halkjaer Nielsen
Summary: A study investigated the genomic potential for exopolysaccharide biosynthesis in bacterial species typical in activated sludge (AS) systems based on genome mining and gene synteny analyses. Putative gene clusters associated with the biosynthesis of various exopolysaccharides were identified in AS bacteria. This study provides a comprehensive overview of the genome-resolved potential for these exopolysaccharides in AS bacteria and contributes to a better understanding of EPS composition in wastewater treatment systems.
Article
Engineering, Environmental
Giulia Dottorini, Dorottya Sarolta Wagner, Mikkel Stokholm-Bjerregaard, Sergey Kucheryavskiy, Thomas Yssing Michaelsen, Marta Nierychlo, Miriam Peces, Rohan Williams, Per Henrik Nielsen, Kasper Skytte Andersen, Per Halkjaer Nielsen
Summary: Well-functioning and stable microbial communities are critical for the operation of activated sludge wastewater treatment plants. Bioaugmentation has the potential to recover deteriorated systems or support specific processes, but its application in full-scale plants is problematic. In a transplantation experiment between two similar full-scale plants, the treatment performance and effluent quality remained stable, but the recipient plant's microbial community almost completely restored its pre-transplantation structure after 40 days. The addition of unique species from the donor AS was not successful in increasing the abundance of desired species or reducing unwanted bacteria in the recipient plant.
Article
Microbiology
Simon J. J. McIlroy, Andy O. O. Leu, Xueqin Zhang, Rhys Newell, Ben J. J. Woodcroft, Zhiguo Yuan, Shihu Hu, Gene W. W. Tyson
Summary: In this study, a bio-reactor dominated by 'Candidatus Methanoperedens nitroreducens' was characterized using meta-omics and fluorescence in situ hybridization (FISH). Unexpectedly, two morphotypes of 'Ca. M. nitroreducens', coccobacilli microcolonies and planktonic rods, were found to stably co-exist. Genomically identical but distinct in gene expression profiles for carbon metabolism, motility, and cell division were observed in these morphotypes. Additionally, a third phenotype that stored carbon as polyhydroxyalkanoates was observed in some coccobacilli 'Ca. M. nitroreducens'. The phenotypic variation of 'Ca. M. nitroreducens' likely aids their survival and dispersal in sub-optimal environmental conditions.
NATURE MICROBIOLOGY
(2023)
Article
Agricultural Engineering
Agnieszka Garlicka, Katarzyna Umiejewska, Per Halkjaer Nielsen, Adam Muszynski
Summary: The aim of this project was to increase methane production by combining feedstock pretreatment and co-digestion of maize silage with thickened excess sludge. Results showed that pretreatment of sludge alone increased methane production from 0.192 Nml/gVS (sludge + maize silage) to 0.220 Nml/gVS (pretreated sludge + maize silage). However, the energy balance indicated that the additional energy generated was not enough to cover the energy expenditure for the mechanical pretreatment. 16S rRNA gene amplicon sequencing revealed the composition of the microbial community, with Chloroflexi, Bacteroidota, Firmicutes, Proteobacteria, and Actinobacteriota being the most abundant bacteria phyla.
BIORESOURCE TECHNOLOGY
(2023)
Article
Engineering, Environmental
Martin Hjorth Andersen, Lisette Thomsen, Mikkel Stokholm-Bjerregaard, Susan Hove Hansen, Mads Albertsen, Per Halkjaer Nielsen, Soren Eriksen
Summary: The partial nitritation/anammox process is a popular approach for removing nitrogen from sidestreams, but it requires extensive surveillance and monitoring due to its sensitivity to disturbances. In this study, we utilized online sensor data and Nanopore DNA sequencing to monitor the microbial community and detect system disturbances in two full-scale deammonification reactors over a year. DNA surveillance revealed unexpected variations in anammox bacteria, and the composition and dynamics of the surrounding community indicated causes for occasional process disturbances. Monitoring the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) could potentially optimize reactor operation. The use of frequent DNA sequencing was found to be an important supplement to online sensor data for process surveillance and control.
Article
Engineering, Environmental
Marie Riisgaard-Jensen, Giulia Dottorini, Marta Nierychlo, Per Halkjaer Nielsen
Summary: The immigration of bacteria in influent wastewater has a strong impact on the microbial community of activated sludge in wastewater treatment plants. The use of primary settlers can selectively increase or reduce the abundance of certain bacteria. The process of primary settling changes the microbial community of influent wastewater and can be a candidate for upstream control to optimize the assembly of microbial communities in activated sludge.
Article
Ecology
Jie Li, Tao Liu, Simon J. McIlroy, Gene W. Tyson, Jianhua Guo
Summary: Metagenomic and metatranscriptomic analyses were performed to reveal the microbial ecology of two biofilm systems that achieve high-level nitrogen removal through the coupling of anammox and n-DAMO processes in low-strength domestic sewage and high-strength sidestream wastewater. Different nitrogen loadings resulted in different combinations of anammox bacteria and anaerobic methanotrophs, and heterotrophic populations actively performed partial denitrification or DNRA using organic intermediates from methane breakdown. Additionally, two novel genomes belonging to Ca. Methylomirabilis were recovered, with one showing the capability of nitrate-dependent anaerobic methane oxidation.
ISME COMMUNICATIONS
(2023)
Article
Biotechnology & Applied Microbiology
Maarten D. Verhoeven, Per H. Nielsen, Morten K. D. Dueholm
Summary: The researchers introduced an experimental setup, combining 16S rRNA gene amplicon sequencing with plating of dispersed activated sludge bacteria, to rapidly identify the growth conditions that allow for the isolation of key microbial species in activated sludge. They found that agarose plates supplemented with various carbon sources support the growth of many previously uncultivated activated sludge bacteria.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
A. Margarida Teixeira, Ivone Vaz-Moreira, David Calderon-Franco, David Weissbrodt, Sabina Purkrtova, Stanislav Gajdos, Giulia Dottorini, Per Halkjaer Nielsen, Leron Khalifa, Eddie Cytryn, Jan Bartacek, Celia M. Manaia
Summary: Urban wastewater treatment plants (UWTPs) are crucial for reducing pollutant load and protecting water bodies, but they also emit antibiotic resistant bacteria and resistance genes, which have impacts on downstream environments. This study tested a set of biomarkers for antibiotic resistance monitoring and found that qPCR can be a cost-effective and technically accessible approach for monitoring wastewater and downstream environments.
