Article
Engineering, Environmental
Ben Ma, Timothy M. LaPara, Taegyu Kim, Raymond M. Hozalski
Summary: This study investigated the abundance and composition of ammonia-oxidizing microorganisms (AOMs) in full-scale and pilot-scale biofilters. The results showed that AOB had the highest relative abundance, followed by comammox Nitrospira and AOA. The abundance of AOB in the pilot-scale biofilters was influenced by influent ammonia concentration and temperature, while AOA and comammox Nitrospira were not correlated with these parameters. The biofilters affected AOM abundance but had a minor influence on the composition of AOB and Nitrospira sublineage II communities.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2023)
Article
Fisheries
Paula Rojas-Tirado, Sanni L. Aalto, Ase Atland, Carlos Letelier-Gordo
Summary: The study demonstrates that different RAS environments exhibit varying dynamics in the production of hydrogen sulphide (H2S), with biofilters producing large quantities under anoxic conditions and solid waste showing a lower but constant production. These sources of H2S can be controlled through optimal operational conditions and fast removal of solids from rearing tanks.
Article
Environmental Sciences
Wei Sun, Lijing Jiao, Jiapeng Wu, Mingken Wei, Yiguo Hong
Summary: The distribution and response of Nitrospira in the subterranean estuary (STE) are still limited. This study investigated the abundance and community structure of Nitrospira along transects in the Daya Bay and found a vertical distribution pattern influenced by dissolved organic carbon, salinity, and ammonium. These findings provide insights into the role of Nitrospira in nitrite oxidation and their physiological metabolism.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Monica Escola Casas, Miriam Guivernau, Marc Vinas, Belen Fernandez, Rafaela Caceres, Carme Biel, Victor Matamoros
Summary: About 13% of monitored groundwater stations in Europe exceed the permitted levels of nitrates, while about 7% exceed the permitted levels of pesticides. This study evaluated the performance of using wood pellets and granulated cork as carbon sources in biofilters for removing nitrates and pesticides. The water-saturated wood biofilter achieved the best nitrate removal, while the cork biofilters lost their denitrification power over time. All biofilters showed high removal rates for certain pesticides.
Article
Multidisciplinary Sciences
Manuel Harringer, Albin Alfreider
Summary: Research revealed that Comammox in freshwater lakes has a low abundance in the water column and plays a minor role in the nitrification process, but shows a strong preference for a particle-attached lifestyle in an oxygen gradient.
SCIENTIFIC REPORTS
(2021)
Article
Agricultural Engineering
Michiel Van Tendeloo, Yankai Xie, Wannes Van Beeck, Weiqiang Zhu, Sarah Lebeer, Siegfried E. Vlaeminck
Summary: Selective suppression of nitrite oxidizing bacteria (NOB) was achieved in a biofilm-based system through oxygen control and recurrent exposure to free ammonia (FA), offering potential for resource efficient nitrogen removal.
BIORESOURCE TECHNOLOGY
(2021)
Editorial Material
Biochemistry & Molecular Biology
Nico Bluethgen, Michael Staab
Summary: A new study has found that large mammals in an African savanna not only change the vegetation but also significantly impact the interaction networks between plants and pollinators. These findings have raised fundamental yet unresolved questions about the spatial dimensions of experiments, species interaction networks, and ecosystems.
Article
Biotechnology & Applied Microbiology
Carolina Suarez, Christopher J. Sedlacek, David J. I. Gustavsson, Alexander Eiler, Oskar Modin, Malte Hermansson, Frank Persson
Summary: Functional redundancy, a common feature of microbial communities, is not always advantageous. Disturbances can be used to manage the functional redundancy of biofilm microbiomes, as shown in the study on nitrite oxidation in wastewater treatment.
NPJ BIOFILMS AND MICROBIOMES
(2022)
Article
Multidisciplinary Sciences
Magdalena Domanska, Magdalena Kusnierz, Katarzyna Mackiewicz
Summary: Despite various wastewater treatment solutions, activated sludge (AS) remains the most common method. The composition of AS is primarily influenced by the raw sewage composition, dissolved oxygen level, and technological solutions, among other factors. This article addresses the lack of data on microorganisms present in water bodies and their potential impact on treatment technology. Fluorescence in situ hybridization (FISH) was used to identify and quantify microorganisms in AS and the outflow of two wastewater treatment plants (WWTPs). The results showed that certain bacteria in the treated wastewater reflected their abundance in the AS, with increased abundance of specific bacteria in the outflow during winter.
SCIENTIFIC REPORTS
(2023)
Article
Biotechnology & Applied Microbiology
Adrien Vigneron, Perrine Cruaud, Johanne Aube, Remy Guyoneaud, Marisol Goni-Urriza
Summary: The study used genome-resolved metagenomic and metatranscriptomic analysis to investigate mercury cycling in microbial mats contaminated by mercury. Rare microorganisms were found to play a major role in mercury cycling, with methylators exhibiting a wide range of metabolic activities under suboxic to anoxic conditions. Additionally, mercury detoxification processes were found to be carried out by specific populations such as sulfide-oxidizing Thiotrichaceae and mercury reducers included various microbial groups, including sulfur- and iron-reducing Desulfuromonadaceae.
NPJ BIOFILMS AND MICROBIOMES
(2021)
Article
Environmental Sciences
Przemyslaw Kowal, Mohamad-Javad Mehrani, Dominika Sobotka, Slawomir Ciesielski, Jacek Makinia
Summary: In this study, the coexistence and interactions of nitrifying bacteria were explored at decreasing solids retention times (SRTs). The results showed that the progressive SRT reduction was inefficient for the out-selection of canonical nitrite oxidizing bacteria (NOB), but the dominant NOB switched from Nitrospira to Ca. Nitrotoga. These findings are important for optimizing NOB suppression strategies in novel nitrogen removal processes.
ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Qintong Li, Ryo Hasezawa, Riho Saito, Kunihiro Okano, Kazuya Shimizu, Motoo Utsumi
Summary: Recirculating aquaculture systems (RAS) play an important role in water quality management and water conservation. This study compared the community structures of micro-ecosystems in RAS systems operated at different temperatures in a marine aquarium. It was found that AOA was the primary nitrifier in the biofilters, and its abundance and diversity were higher in high-temperature samples. NOB showed similar relative abundance patterns to AOA, suggesting a cooperative relationship between the two in the marine RAS system.
Review
Biotechnology & Applied Microbiology
Shanshan Meng, Xueji Liang, Tao Peng, Yongjin Liu, Hui Wang, Tongwang Huang, Ji-Dong Gu, Zhong Hu
Summary: This article reviews the importance of Comammox bacteria in studying nitrification and expanding the understanding of the nitrogen cycle. It highlights their crucial role in wastewater treatment and greenhouse gas flux in natural and engineered environments. However, there is limited research on the Comammox bacteria and their role in ammonia and nitrite oxidation in the environment. The review focuses on summarizing the genomes of Nitrospira in the NCBI database, discussing the ecological distribution and the influence of environmental parameters on this genus, and exploring their role in carbon, nitrogen, and sulfur cycles.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2023)
Article
Environmental Sciences
Mengyue Zhao, Xiufeng Tang, Dongyao Sun, Lijun Hou, Min Liu, Qiang Zhao, Uli Klumper, Zhexue Quan, Ji-Dong Gu, Ping Han
Summary: The recent discovery of complete ammonia oxidizers (comammox) challenges the traditional understanding of nitrification, showing that one organism can convert ammonia to nitrate. This study on nitrifying microorganisms in the Nanliu estuary demonstrates the niche specificity of different nitrifiers modulated mainly by salinity. The research also reveals a clear response by comammox Nitrospira to a wide range of simulated salinity levels.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Physics, Multidisciplinary
Thibaut Arnoulx de Pirey, Guy Bunin
Summary: Models of many-species ecosystems suggest that these systems often experience near-extinction processes, where population sizes approach zero for a period of time before rebounding, accompanied by a slowdown in dynamics (aging). In this study, a solvable many-variable model is introduced to investigate the connection between near-extinction and aging. It is found that aging is a generic phenomenon when random interactions occur between populations. Population sizes remain exponentially close to the absorbing values for extended periods, with rapid transitions between the two values. The mechanism for aging is different from that in typical glassy systems, with the system evolving near unstable fixed points rather than marginal ones.
PHYSICAL REVIEW LETTERS
(2023)