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
Biotechnology & Applied Microbiology
Georgios Manthos, Leila Abbaszadeh, Dimitris Zagklis, Michael Kornaros
Summary: In this study, a comprehensive mathematical model was developed to describe the nitrification process in mixed cultures involving isolated NOB and starved AOB, allowing for a more accurate representation of the biological dynamics during starvation conditions. The accuracy of the model was confirmed by testing its predictions against experimental data. This model provides insights into the intricate mechanisms underlying nitrification, contributing to the advancement of sustainable wastewater treatment practices.
FERMENTATION-BASEL
(2023)
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
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
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
Environmental Sciences
Ahmed Elsayed, Jaecheul Yu, Taeho Lee, Younggy Kim
Summary: This study proposed a real-time aeration scheme based on nitrite concentration to control the competition between nitrite oxidizing bacteria (XNOB) and Anammox bacteria (XANA) in single-stage Anammox processes. The simulation results showed that maintaining dissolved oxygen (DO) at around 0.10 mg-O2/L was ideal for effective nitrite creation by ammonia oxidizing bacteria (XAOB) while slowing down the growth of XNOB. Nitrite concentration was found to be the rate-limiting parameter for efficient nitrogen removal in single-stage Anammox processes.
ENVIRONMENTAL RESEARCH
(2022)
Article
Ecology
Xiaoping Fan, Hao Chen, Guochao Yan, Mujun Ye, Chang Yin, Tingqiang Li, Steven A. Wakelin, Yongchao Liang
Summary: This study investigated the efficacy of nitrification inhibitors (NIs) and their effects on soil microbiota in different arable soils. The results showed that NI application suppressed the abundance of ammonia-oxidizing bacteria and increased the abundance of nosZI-N2O reducers. The efficacy of different NIs varied in different soils.
Article
Biotechnology & Applied Microbiology
Maria Kolovou, Dimitra Panagiotou, Lars Susse, Olivier Loiseleur, Simon Williams, Dimitrios G. Karpouzas, Evangelia S. Papadopoulou
Summary: This study provides pioneering evidence for the activity range of multiple plant-derived compounds as biological nitrification inhibitors (BNIs) on soil nitrifiers. It highlights the differential sensitivity of ammonia-oxidizing bacteria (AOB) and ammonia-oxidizing archaea (AOA) to BNIs and emphasizes the potential implications of BNIs on soil quality and productivity. This research contributes to a deeper understanding of the effect of BNIs on the overall soil microbiome integrity and calls for a reevaluation of the current biological screening systems for BNI determination.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)
Article
Engineering, Environmental
Xiaodan Gu, Yong Huang, Yuting Hu, Wenhui Huang, Miao Zhang
Summary: Stable partial nitrification is still challenging to achieve under mainstream conditions. The study found that a low nitrite concentration is crucial for suppressing the growth of nitrite-oxidizing bacteria (NOB), and there is a significant correlation between nitrite levels and the percentage of NOB in bacterial communities.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(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
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
Tianli Ma, Cheng Cheng, Lizhen Xing, Yuepeng Sun, Guangxue Wu
Summary: A better understanding of r-/K-strategists nitrifiers will help to balance the design and operation of bioprocesses for efficient pollution removal from wastewater. The study investigated the biokinetics, biofilm property, microbial community, and quorum sensing (QS) of nitrifying biofilm in a continuously flow reactor (CFR) and a sequencing batch reactor (SBR). Results showed that Nitrospira and Candidatus Nitrospira defluvii were the dominant nitrite-oxidizing taxa in both reactors. The biofilm in SBR had higher ratios of polysaccharide and protein in extracellular polymeric substances and higher thickness compared to CFR. AHLs-based QS might affect the formation of nitrifying biofilm and contribute to the different biokinetics of Nitrospira in CFR and SBR.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Zhen Lei, Lianxu Wang, Jun Wang, Shuming Yang, Zhaoyang Hou, Xiaochang C. Wang, Rong Chen
Summary: This study demonstrates that operating at higher dissolved oxygen concentrations can effectively improve the performance of the partial nitritation reactor, enhancing ammonia oxidation and reducing nitrite accumulation simultaneously.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Xenia Juan-Diaz, Julio Perez, Julian Carrera
Summary: This study demonstrated that the up-flow anammox sludge bed reactor was able to maintain a high nitrogen removal rate even with a 10-degree temperature drop at mainstream conditions. The difference in anammox activity among different sludge bed sections allowed for efficient nitrogen removal even at lower temperatures. The microbial community analysis identified high numbers of uncharacterized Planctomycetes, indicating potential for anammox bacteria feasibility in urban wastewater treatment plants under low temperature conditions.
JOURNAL OF WATER PROCESS ENGINEERING
(2021)
Review
Engineering, Environmental
Aina Soler-Jofra, Julio Perez, Mark C. M. van Loosdrecht
Summary: Aerobic ammonium oxidizing bacteria have been identified more than 100 years ago, with hydroxylamine being known as an intermediate. Recent enzymatic evidence suggests that hydroxylamine is converted to NO and further to nitrite by an unknown enzyme. The nitrogen losses in the form of NO and N2O from three types of aerobic ammonium oxidizing microorganisms, as well as the inhibitory role of hydroxylamine on nitrite oxidizing bacteria, are still under investigation.
Article
Environmental Sciences
Sankalp Arya, Alexander Williams, Saul Vazquez Reina, Charles W. Knapp, Jan-Ulrich Kreft, Jon L. Hobman, Dov J. Stekel
Summary: Many antibiotic resistance genes co-occur with resistance genes for transition metals, such as copper, zinc, or mercury. Mathematical modelling is used to predict minimal co-selective concentrations for metals, aiding in the mitigation of risks of antimicrobial resistance.
ENVIRONMENTAL POLLUTION
(2021)
Article
Biotechnology & Applied Microbiology
J. Kimberley Summers, Jan-Ulrich Kreft
Summary: This research used mathematical models to study bacterial predation in realistic slow growth conditions and found that the generalist predator Bdellovibrio is most effective within a narrow range of conditions for each prey. The study also revealed the importance of the parameters relationship between predator and prey in determining predation efficiency and explained why Bdellovibrio needs to be a generalist predator.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Microbiology
Feng Dong, Ana C. Quevedo, Xiang Wang, Eugenia Valsami-Jones, Jan-Ulrich Kreft
Summary: The study found that bacteria displayed significant differences in evolutionary mutations when treated with silver ions or silver nanoparticles, suggesting the presence of nanoparticle-specific effects potentially caused by sustained release of silver ions from nanoparticle dissolution, direct action of nanoparticles on the cell's outer membrane, or more proximate release of ions from cell-surface bound nanoparticles.
ENVIRONMENTAL MICROBIOLOGY
(2022)
Article
Engineering, Environmental
Aina Soler-Jofra, Lisbeth Schmidtchen, Lluc Olmo, Mark C. M. van Loosdrecht, Julio Perez
Summary: This study investigates the short and long term impact of hydroxylamine on partial nitritation granular sludge. The results indicate that dissolved oxygen is the main factor determining the impact of hydroxylamine. Short term hydroxylamine feeding with low dissolved oxygen leads to higher hydroxylamine accumulation and N2O production, while long term hydroxylamine feeding reduces ammonium consumption rate.
Article
Engineering, Environmental
Xenia Juan-Diaz, Julian Carrera, Julio Perez
Summary: This study explored the operating conditions involved in the development of autotrophic aerobic granular sludge. The results showed that enhancing ammonium oxidation activity in the early phase was crucial for the stable development of autotrophic aerobic granular sludge.
JOURNAL OF WATER PROCESS ENGINEERING
(2022)
Article
Public, Environmental & Occupational Health
Nasreen Hassoun-Kheir, Yoav Stabholz, Jan-Ulrich Kreft, Roberto de la Cruz, Arnaud Dechesne, Barth F. Smets, Jesus L. Romalde, Alberto Lema, Sabela Balboa, Carlos Garcia-Riestra, Eva Torres-Sangiao, Ami Neuberger, David Graham, Marcos Quintela-Baluja, Dov J. Stekel, Jay Graham, Amy Pruden, Joseph Nesme, Soren Johannes Sorensen, Rupert Hough, Mical Paul
Summary: By utilizing a systematic review and Delphi consensus method, the EMBRACE-WATERS statement was developed as a checklist of recommendations for reporting studies of AMR in wastewater and related aquatic environments. The consensus among a multidisciplinary panel of experts resulted in 21 items comprising essential elements for high-quality reporting, with explanations and reporting examples provided for each item. The statement aims to improve reporting quality, facilitate communication among researchers, and guide peer-reviewers and editors in evaluating manuscripts in the field of AMR research in aquatic environments.
Article
Engineering, Environmental
Xenia Juan-Diaz, Lluc Olmo, Julio Perez, Julian Carrera
Summary: Mainstream partial nitritation/anammox (PN/AMX) has gained significant attention, and two-stage configurations have been proposed as an attractive technology. However, the process requires further improvement by designing a new technology to remove nitrate produced by anammox bacteria. A new reactor configuration coupling anammox with heterotrophic denitrification was developed, showing successful coexistence of both processes.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Green & Sustainable Science & Technology
Julian Carrera, Oriol Carbo, Silvia Donate, Maria Eugenia Suarez-Ojeda, Julio Perez
Summary: The potential of high-rate activated sludge (HRAS) reactors for COD removal in urban wastewater treatment plants (WWTPs) was investigated. A pilot plant treating the effluent of a full-scale WWTP was studied for one year. The study found that HRAS performed better at higher sludge retention time (SRT) but experienced higher loss of organic matter at lower SRT. Coupling HRAS with autotrophic biological nitrogen removal (BNR) significantly improved energy generation.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Environmental Sciences
Michelle Baker, Alexander D. Williams, Steven P. T. Hooton, Richard Helliwell, Elizabeth King, Thomas Dodsworth, Rosa Maria Baena-Nogueras, Andrew Warry, Catherine A. Ortori, Henry Todman, Charlotte J. Gray-Hammerton, Alexander C. W. Pritchard, Ethan Iles, Ryan Cook, Richard D. Emes, Michael A. Jones, Theodore Kypraios, Helen West, David A. Barrett, Stephen J. Ramsden, Rachel L. Gomes, Chris Hudson, Andrew D. Millard, Sujatha Raman, Carol Morris, Christine E. R. Dodd, Jan-Ulrich Kreft, Jon L. Hobman, Dov J. Stekel
Summary: Waste from dairy production is a significant source of contamination from antimicrobial resistant bacteria and genes. Storing slurry waste for at least 60 days can significantly reduce the spread of ARB onto land. Furthermore, further reductions in AMR are unlikely on farms with low antibiotic use.
ENVIRONMENT INTERNATIONAL
(2022)
Review
Microbiology
J. Kimberley Summers, Jan-Ulrich Kreft
Summary: With the increasing levels of antimicrobial resistance, there is an urgent need for novel means of treating resistant infections. Bacteriophages and predatory bacteria have been proposed as suitable candidates for this role. Mathematical models have been used to investigate the mechanisms of action of predators and predict the dynamics of predator-prey systems. These models have also provided insights into the qualitative and quantitative similarities or differences between bacterial predators and bacteriophages or protists. Additionally, models have helped study the effectiveness of predators in removing prey species and their potential effects on shaping ecosystems. Overall, mathematical models have played a crucial role in understanding and predicting the behavior of prokaryotic predators.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Biochemical Research Methods
Danesh Moradigaravand, Liguan Li, Arnaud Dechesne, Joseph Nesme, Roberto de la Cruz, Huda Ahmad, Manuel Banzhaf, Soren J. Sorensen, Barth F. Smets, Jan-Ulrich Kreft
Summary: Wastewater treatment plants (WWTPs) contain diverse microbial communities that receive antimicrobial residues and resistant strains, allowing for horizontal gene transfer (HGT) of antimicrobial resistance (AMR) determinants. This study used machine learning models to predict plasmid permissiveness in water cycle microbial communities, which is the ability of cells to receive a plasmid through conjugation. The results showed a moderate-to-strong correlation between predicted and experimental permissiveness, indicating the potential for assessing the risk of AMR pollution in wastewater systems.
Editorial Material
Engineering, Environmental
Jan-Ulrich Kreft
Article
Biotechnology & Applied Microbiology
Henriette Lyng Roder, Eleni Christidi, Cristina I. Amador, Samra Music, Asmus Kalckar Olesen, Birte Svensson, Jonas Stenlokke Madsen, Jakob Herschend, Jan-Ulrich Kreft, Mette Burmolle
Summary: The study revealed that flagella play a significant role in impacting plasmid transfer and uptake in bacterial biofilms, with mechanisms such as steric hindrance of pilus movement and binding reducing the frequency of contact and plasmid uptake. This finding adds a new layer of complexity to understanding bacterial conjugation in biofilms beyond traditional factors like distance and lag times.
APPLIED AND ENVIRONMENTAL MICROBIOLOGY
(2023)