Article
Environmental Sciences
Mingyue Li, Hui He, Tiezhu Mi, Yu Zhen
Summary: In this study, the spatiotemporal dynamics of ammonia-oxidizing archaea (AOA) and bacteria (AOB) and their contribution to nitrification were investigated in the Bohai Sea and Yellow Sea. The results showed that AOA had a greater contribution to nitrification than AOB in coastal sediments, and both seasons and sea areas had significant effects on the abundance and potential nitrification rate of AOA and AOB.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Xia Jia, Yunfeng Gao, Xiaodi Li, Yonghua Zhao, Lu Wang, Chunyan Zhang
Summary: This study investigated the impacts of elevated CO2 and cadmium levels on soil nitrification in the rhizosphere of Robinia pseudoacacia L. seedlings. The results showed that elevated CO2 combined with Cd pollution generally stimulated nitrification enzyme activities and influenced bacterial community structures.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Soil Science
Haiyang Liu, Hangwei Hu, Xing Huang, Tida Ge, Yongfu Li, Zhenke Zhu, Xingmei Liu, Wenfeng Tan, Zhongjun Jia, Hongjie Di, Jianming Xu, Yong Li
Summary: Chemoautotrophic canonical ammonia-oxidizers play a significant role in autotrophic nitrification during the mineralization of organic substances with low C/N ratios in paddy soils, as shown by N-15 tracing and DNA-SIP techniques.
SOIL BIOLOGY & BIOCHEMISTRY
(2021)
Article
Soil Science
Yongxin Lin, Hang-Wei Hu, Guiping Ye, Jianbo Fan, Weixin Ding, Zi-Yang He, Yong Zheng, Ji-Zheng He
Summary: The meta-analysis of laboratory incubation studies with 1-octyne as the nitrification inhibitor shows that AOB play a more dominant role in soil nitrification in cropland than in wetland soils, indicating a major role of AOB in acidic soil nitrification. Moreover, the reduction of nitrification rate by 1-octyne is greater in soils incubated in slurry and with nitrogen additions, suggesting AOB's importance in nitrification in global acidic soils.
Article
Biotechnology & Applied Microbiology
Elizabeth French, Jessica A. Kozlowski, Annette Bollmann
Summary: The study found that ammonia-oxidizing archaea are more abundant in systems with low ammonium availabilities, while ammonia-oxidizing bacteria are more abundant when ammonium availability increases. Population dynamics of ammonia oxidizers may shift in response to changes in ammonium concentrations.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2021)
Article
Microbiology
Jonathan Rodriguez, Seemanti Chakrabarti, Eunkyung Choi, Nisreen Shehadeh, Samantha Sierra-Martinez, Jun Zhao, Willm Martens-Habbena
Summary: The discovery of ammonia-oxidizing archaea (AOA) and complete ammonia-oxidizing (comammox) bacteria in terrestrial ecosystems highlights their important role in nitrification. A nutrient-limited enrichment strategy was found to favor the growth of comammox bacteria with high affinity and yield. Direct enrichment from soil and nutrient-limited sub-cultivation consistently yielded high enrichments of Nitrosocosmicus-affiliated AOA associated with multiple canonical nitrite-oxidizing Nitrospira strains.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Environmental Sciences
Dumsane Themba Matse, Paramsothy Jeyakumar, Peter Bishop, Christopher W. N. Anderson
Summary: This study investigated the effects of applying Cu-complexing compounds on nitrification rate, abundance of ammonia-oxidizing bacteria and archaea genes, and mineral nitrogen leaching in urine patches. The results showed that using organic compounds such as co-poly-acrylic-maleic acid and calcium lignosulphonate can significantly reduce the copper content in the soil, thereby reducing mineral nitrogen leaching.
ENVIRONMENTAL POLLUTION
(2023)
Article
Environmental Sciences
Ting Lan, Yuxiao Huang, Xi Song, Ouping Deng, Wei Zhou, Ling Luo, Xiaoyan Tang, Jian Zeng, Guangdeng Chen, Xuesong Gao
Summary: Nitrogen management measures such as urease inhibitors, synthetic nitrification inhibitors, and biochar are commonly used in agriculture to mitigate nitrogen loss and increase fertilizer recovery efficiency. In a study conducted on calcareous soil under rice cropping, it was found that a combination of BNIs and UIs had the most effective results in reducing nitrogen loss and improving FRE by utilizing synergistic effects.
ENVIRONMENTAL POLLUTION
(2022)
Article
Plant Sciences
Adrian Bozal-Leorri, Guntur Subbarao, Masahiro Kishii, Leyre Urmeneta, Victor Kommerell, Hannes Karwat, Hans-Joachim Braun, Pedro Ma Aparicio-Tejo, Ivan Ortiz-Monasterio, Carmen Gonzalez-Murua, Ma Begona Gonzalez-Moro
Summary: Synthetic nitrification inhibitors (SNI) and biological nitrification inhibitors (BNI) are promising tools to limit agricultural nitrogen pollution. Introducing the chromosome region (Lr#n-SA) controlling BNI production into wheat cultivars can enhance nitrogen uptake and utilization.
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Soil Science
Ting Lan, Mengxiao Li, Xiaoqian He, Ouping Deng, Wei Zhou, Ling Luo, Guangdeng Chen, Shu Yuan, Jing Ling, Min Zeng, Xuesong Gao
Summary: An aerobic N-15 microcosmic experiment was conducted to compare the inhibitory effects of the biological nitrification inhibitor (BNI), methyl 3-(4-hydroxyphenyl) propionate (MHPP) and the synthetic nitrification inhibitor 3,4-dimethylpyrazole phosphate (DMPP) on the gross nitrification rate and the abundance and community composition of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) in contrasting soils. The results showed that the two inhibitors had different effects on nitrification rates and the response of AOB to the inhibitors was more sensitive.
BIOLOGY AND FERTILITY OF SOILS
(2022)
Article
Environmental Sciences
Feng Wang, Xiaolong Liang, Shihan Ma, Lingzhi Liu, Jingkuan Wang
Summary: The study found that ammonia-oxidizing archaea and ammonia-oxidizing bacteria had significantly higher transcriptional abundance of amoA gene in soils compared to complete ammonia oxidizers, suggesting the former may be the dominant contributors to soil nitrification. Seasonal variation and fertilization regimes substantially affected the abundance of ammonia-oxidizing microbes, with ammonia-oxidizing bacteria being less sensitive to these factors compared to ammonia-oxidizing archaea.
JOURNAL OF SOILS AND SEDIMENTS
(2021)
Article
Engineering, Environmental
Guoqiang Liu, Xianwei Wu, Deyong Li, Lugao Jiang, Ju Huang, Li Zhuang
Summary: The study showed that short-term low dissolved oxygen increased N2O emissions, while long-term low DO decreased emissions by increasing the abundance of ammonia oxidizers in the ASP. Long-term low DO reduced AOB abundance but increased AOA, with AOA potentially inhibiting N2O production. The positive correlation between N2O emissions and nitrite concentration became insignificant after 80 days of low DO operation, suggesting that ASPs can reduce N2O production and CO2 emissions by operating with low DO and extended sludge age.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Biodiversity Conservation
Weifang Hu, Mianrun Chen, Xue Lan, Guoliang Li, Bin Wang, Dong Yao Sun, Xianbiao Lin
Summary: This study found significant shifts in potential ammonia oxidation rates (PARs) and gene abundances of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) along different salinity gradients. The PARs were higher under high salinity conditions, and the AOB gene abundance was greater than AOA under moderate and high salinity. This has important implications for nitrogen cycling in estuarine sediments.
ECOLOGICAL INDICATORS
(2022)
Article
Environmental Sciences
Shishi He, Zhirong Zhao, Zhichao Tian, Chi Xu, Yuan Liu, Da He, Yinghui Zhang, Maosheng Zheng
Summary: This study analyzed activated sludge samples from municipal and industrial wastewater treatment plants and found that comammox bacteria were more abundant than ammonia-oxidizing bacteria and ammonia-oxidizing archaea in municipal plants, while this trend did not hold true for industrial plants. Furthermore, a higher diversity of comammox bacteria was found in municipal samples. This study provides important insights into the abundance and diversity of comammox bacteria in municipal and refinery wastewater treatment systems.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2022)
Article
Ecology
Yongping Kou, Chaonan Li, Bo Tu, Jiabao Li, Xiangzhen Li
Summary: The assembly mechanisms of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) communities along an altitudinal gradient were investigated. The study found that the alpha-diversity of AOA communities decreased monotonically with increasing elevation, while a sinusoidal pattern was observed for AOB communities. Mean annual temperature was the most influential factor for the alpha-diversity of AOA communities, while plant richness, soil conductivity, and total nitrogen made comparable contributions to the alpha-diversity of AOB communities. Additionally, beta-diversity of AOA and AOB communities were divided into two distinct clusters by elevation, mainly attributed to soil pH and variations in plant richness. AOB communities contributed more to soil nitrification potential in the low-altitude section, while AOA communities were more important in the high-altitude section.
Article
Environmental Sciences
Jukka-Pekka Myllykangas, Antti J. Rissanen, Susanna Hietanen, Tom Jilbert
Article
Ecology
Xin Sun, Claudia Frey, Emilio Garcia-Robledo, Amal Jayakumar, Bess B. Ward
Summary: The study reveals variations in the response of nitrite oxidation to nitrite and oxygen concentrations along a redox gradient in a Pacific Ocean oxygen minimum zone, indicating niche differentiation of nitrite-oxidizing assemblages, including responses to oxygen concentrations. Additionally, full inhibition of nitrite oxidation by oxygen addition and nitrite oxidation coupled with nitrogen loss in anoxic waters were observed. Novel clades of nitrite-oxidizing bacteria were detected with high relative abundance in anoxic depths, suggesting mechanisms of niche differentiation across the redox gradient.
Article
Ecology
Xin Sun, Amal Jayakumar, John C. Tracey, Elizabeth Wallace, Colette L. Kelly, Karen L. Casciotti, Bess B. Ward
Summary: The study expands N2O consumption measurements from anoxic zones to oxic waters, revealing differences in the characteristics of N2O-consuming microbes. Experimental results suggest that microbes in the dynamic layer with steep oxygen and N2O gradients above the oxygen deficient zone play a significant role in N2O consumption.
Article
Engineering, Environmental
Xuefeng Peng, Qixing Ji, John H. Angell, Patrick J. Kearns, Jennifer L. Bowen, Bess B. Ward
Summary: Salt marsh sediments are key sites for nitrogen cycling and a significant source of nitrous oxide (N2O) production and consumption. Fertilization can impact nitrogen dynamics, increasing the importance of nitrification in N2O production. Changes in specific substrate utilization rates reveal shifts in microbial community composition and functional gene expression in response to long-term fertilization.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Marine & Freshwater Biology
Sanni L. Aalto, Eero Asmala, Tom Jilbert, Susanna Hietanen
Summary: Coastal environments play a crucial role in regulating the transfer of nitrogen from land to sea, with variations in nitrate reduction processes between estuary and offshore archipelago environments in the Baltic Sea. The balance between denitrification and DNRA processes is influenced by the ratio of nitrate to autochthonous organic carbon, impacting the release of nitrous oxide and efficiency of nitrogen recycling in different coastal areas.
ESTUARINE COASTAL AND SHELF SCIENCE
(2021)
Article
Biotechnology & Applied Microbiology
Julia Carroll, Nicolas Van Oostende, Bess B. Ward
Summary: Accurate calculation of microbial growth rates is crucial for understanding the role of bacteria in marine carbon and nitrogen cycles. However, DNA sequencing-based methods are unable to accurately interpret bacterial growth rates despite their correlation with cell cycle.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Geochemistry & Geophysics
Jessica A. Lueders-Dumont, Atleigh G. Forden, Emma R. Kast, John A. Mohan, Benjamin D. Walther, Daniel M. Sigman, Bess B. Ward
Summary: The use of nitrogen isotopes can effectively track the life history of organisms following dietary changes. Otoliths and tissues show different response times to new diets, with slower growth tissues exhibiting larger variations. Further optimization of sampling methods may improve resolution for tracking diet changes.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2022)
Article
Environmental Sciences
Xianhui S. Wan, Hua-Xia Sheng, Minhan Dai, Matthew J. Church, Wenbin Zou, Xiaolin Li, David A. Hutchins, Bess B. Ward, Shuh-Ji Kao
Summary: This study reveals that the distribution of nitrite in the ocean is influenced by interactions between phytoplankton, nitrifiers, and environmental factors such as light and nutrient availability. The processes controlling nitrite cycling vary across different regions, leading to differential nitrite concentrations and turnover rates.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
Article
Limnology
Mhlangabezi Mdutyana, Xin Sun, Jessica M. Burger, Raquel F. Flynn, Shantelle Smith, Natasha R. Horsten, Alakendra N. Roychoudhury, Helene Planquette, Eva Bucciarelli, Sandy J. Thomalla, Bess B. Ward, Sarah E. Fawcett
Summary: The seasonal alternation between upward mixing of nutrients and their subsequent consumption by phytoplankton is crucial for the role of the Southern Ocean in setting atmospheric CO2. The uptake and oxidation of NH4+ in the Southern Ocean are dependent on season and NH4+ concentration, with iron availability potentially limiting NH4+ oxidation. Iron depletion may also limit the role of winter nitrification in offsetting phytoplankton CO2 drawdown.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Limnology
Weiyi Tang, John C. Tracey, Julia Carroll, Elizabeth Wallace, Jenna A. Lee, Levy Nathan, Xin Sun, Amal Jayakumar, Bess B. Ward
Summary: Estuaries, such as the Chesapeake Bay, are important and uncertain sources of nitrous oxide (N2O) emissions. This study investigated the contributions of nitrification and denitrification to N2O production in the Chesapeake Bay using multiple N-15 tracers. The results showed that nitrification was the major pathway for N2O production in oxic waters, while denitrification dominated in hypoxic/anoxic waters. The study also observed N2O production from urea for the first time in estuarine waters. Lowering oxygen concentrations significantly increased N2O production. These findings enhance our understanding of N2O dynamics in estuarine environments and can improve N2O flux estimates in the Chesapeake Bay and other coastal areas.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Geosciences, Multidisciplinary
Weiyi Tang, Amal Jayakumar, Xin Sun, John C. Tracey, Julia Carroll, Elizabeth Wallace, Jenna A. Lee, Levy Nathan, Bess Ward
Summary: The study found that N2O consumption rates are high in the seasonally anoxic environment of Chesapeake Bay, but generally undetectable in oxygenated waters. However, when the oxygen concentration was reduced in oxygenated samples, N2O consumption rates increased significantly, indicating the potential for N2O consumption in oxygenated environments. These new observations provide insights into N2O cycling processes and can be used to improve the modeling of N2O flux in estuaries.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Environmental Sciences
Xianhui S. Wan, Hua Lin, Bess B. Ward, Shuh-Ji Kao, Minhan Dai
Summary: The coastal ocean and marginal sea are important sources of nitrous oxide (N2O) emissions into the atmosphere, but the spatial and temporal distribution of N2O in these regions is still uncertain due to lack of measurements. This study presents a large dataset of N2O concentrations and fluxes obtained from 10 cruises in the Northern South China Sea (NSCS). The results show that the NSCS is a net source of atmospheric N2O, with variations in fluxes across different regions and seasons. The study also highlights the influence of riverine discharge and the intrusion of the Kuroshio Current on N2O distribution in the NSCS.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Ecology
Mhlangabezi Mdutyana, Tanya Marshall, Xin Sun, Jessica M. Burger, Sandy J. Thomalla, Bess B. Ward, Sarah E. Fawcett
Summary: Nitrification in the winter Southern Ocean is dominated by nitrite oxidation, and the nitrate produced serves as a nutrient source for subsequent growth. However, this process does not contribute to the removal of atmospheric CO2. Our research indicates that nitrite-oxidizing bacteria (NOB) in the Southern Ocean require a certain threshold level of nitrite concentration to produce nitrate. Additionally, ammonium oxidation rates are higher than nitrite oxidation rates, suggesting that nitrite oxidation is the limiting step for nitrification in the winter Southern Ocean.
Article
Ecology
Kai G. Schulz, Eric P. Achterberg, Javier Aristegui, Lennart T. Bach, Isabel Banos, Tim Boxhammer, Dirk Erler, Maricarmen Igarza, Verena Kalter, Andrea Ludwig, Carolin Loscher, Jana Meyer, Judith Meyer, Fabrizio Minutolo, Elisabeth von der Esch, Bess B. Ward, Ulf Riebesell
Summary: The upwelling of nutrient-rich deep waters in eastern boundary upwelling systems like the Humboldt Current system leads to high marine productivity. In oxygen-depleted environments, denitrification and anaerobic ammonium oxidation are major nitrogen loss pathways. Experimental results suggest that denitrification rates are lower than expected due to substrate limitation in the bottom layer waters.
Article
Ecology
Susheel Bhanu Busi, Laura de Nies, Janine Habier, Linda Wampach, Joelle V. Fritz, Anna Heintz-Buschart, Patrick May, Rashi Halder, Carine de Beaufort, Paul Wilmes
Summary: This study recovered 39 high- and medium-quality metagenome-assembled genomes (MAGs) from the Eastern Tropical South Pacific OMZ, shedding light on previously unrepresented microbial populations. The OMZ MAGs were dominated by denitrifiers, with a novel bacterial genome and versatile archaeon displaying potential for multiple nitrogen compound respiration. These newly discovered denitrifying MAGs provide insights into microbial adaptation strategies and the evolution of denitrification in the tree of life.
ISME COMMUNICATIONS
(2021)