Article
Environmental Sciences
Jingying Xu, Van Liem-Nguyen, Moritz Buck, Stefan Bertilsson, Erik Bjorn, Andrea G. Bravo
Summary: The study identified diverse clades of potential Hg-II methylators in wetland soils, including various bacteria and archaea. It also found that local physicochemical conditions are crucial for shaping the structure of Hg methylating microbial communities in wetlands.
FRONTIERS IN ENVIRONMENTAL SCIENCE
(2021)
Article
Microbiology
Borja Aldeguer-Riquelme, Esther Rubio-Portillo, Jose Alvarez-Rogel, Francisca Gimenez-Casalduero, Xose Luis Otero, Maria-Dolores Belando, Jaime Bernardeau-Esteller, Rocio Garcia-Munoz, Aitor Forcada, Juan M. Ruiz, Fernando Santos, Josefa Anton
Summary: Coastal marine lagoons are highly vulnerable to anthropogenic pressures, and sediment microorganisms play a crucial role in mitigating these impacts. This study investigated the microbial communities in the sediment of Mar Menor, a lagoon in Spain heavily impacted by human activities. The results revealed high heterogeneity in microbial communities among different stations, but a core microbiome was identified. Factors such as sediment texture, presence of specific vegetation, depth, and geographic location influenced the microbial assemblages. Additionally, heavily contaminated stations had less stable microbial communities compared to non-contaminated stations, suggesting the presence of specialized bacteria sensitive to change.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Environmental Sciences
Dhiraj Kumar Chaudhary, Rishikesh Bajagain, Donggyun Seo, Yongseok Hong, Seunghee Han
Summary: Metal contamination and other geochemical alterations disrupt microbial composition and functional activities, leading to disturbances in biogeochemical cycles. This study investigated the distribution of total mercury (THg), methylmercury (MeHg), and trace metals in anthropogenically affected sediment. The microbial communities and functional gene profiles were analyzed to explore their relationship with Hg-methylation and geochemical features. Results showed that THg and MeHg levels increased towards the lower horizons of the sediment cores, while Al, Fe, Mn, and Zn were the major metals present at all depths. The enrichment and contamination indices indicated high concentrations of trace metals in the anthropogenically affected sediment. Various functional genes and dominant microbial taxa were detected, with correlations between major taxa and geochemical variables suggesting the significant impact of sediment geochemistry on microbial communities and biogeochemical cycles. Archaeal methanogens and bacterial phyla Chloroflexi and Firmicutes were also implicated in the enhancement of MeHg levels. Overall, these findings provide insights into the microbial communities involved in Hg-methylation process and other biogeochemical cycles.
ENVIRONMENTAL RESEARCH
(2023)
Article
Microbiology
Alyssa A. Carrell, Grace E. Schwartz, Melissa A. Cregger, Caitlin M. Gionfriddo, Dwayne A. Elias, Regina L. Wilpiszeski, Dawn M. Klingeman, Ann M. Wymore, Katherine A. Muller, Scott C. Brooks
Summary: This study utilized high-throughput amplicon sequencing to analyze the microbiome of periphyton communities in a contaminated watershed in East Tennessee, United States. The research found that nutrient amendments impacted the structure and function of periphyton communities and identified specific bacterial families correlated with Hg methylation potential. The study also highlighted the significant role of microbiome structure in influencing rates of Hg transformation within periphyton communities.
FRONTIERS IN MICROBIOLOGY
(2021)
Article
Limnology
Eric Capo, Elias Broman, Stefano Bonaglia, Andrea G. Bravo, Stefan Bertilsson, Anne L. Soerensen, Jarone Pinhassi, Daniel Lundin, Moritz Buck, Per O. J. Hall, Francisco J. A. Nascimento, Erik Bjorn
Summary: The expansion of oxygen-deficient zones in marine systems may lead to a compositional change of Hg-methylating microbial groups in sediments, promoting the expansion of Hg methylators whose metabolism and biology have not yet been characterized.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Engineering, Environmental
Baolin Wang, Haiyan Hu, Kevin Bishop, Moritz Buck, Erik Bjorn, Ulf Skyllberg, Mats B. Nilsson, Stefan Bertilsson, Andrea G. Bravo
Summary: Peatlands are important sources of methylmercury (MeHg) contamination, and microbial activity plays a crucial role in mercury geochemical cycles and MeHg formation. The composition of microbial communities in peatlands varies spatially and is significantly associated with net MeHg formation.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Environmental Sciences
Mingyue Li, Anqi Fang, Xiaoli Yu, Keke Zhang, Zhili He, Cheng Wang, Yisheng Peng, Fanshu Xiao, Tony Yang, Wei Zhang, Xiafei Zheng, Qiuping Zhong, Xingyu Liu, Qingyun Yan
Summary: Microbially-driven sulfur cycling is a critical biogeochemical process in sulfur-rich mangrove ecosystems. This study reveals the diversity, composition, and structure of sulfur-oxidizing bacteria (SOB) and sulfate-reducing bacteria (SRB) in mangrove sediments, highlighting the important role of temperature, redox potential, and key factors like elemental sulfur and total carbon in influencing these microbial communities. Additionally, the morphological transformation of sulfur compounds explains the variations in sulfur cycling microbial communities, with specific dominant genus identified in different mangrove species. These findings shed light on the sulfur cycling dynamics in mangrove ecosystems and offer insights for similar wetland ecosystems from a microbial perspective.
Article
Ecology
Lea C. Wunder, David A. Aromokeye, Xiuran Yin, Tim Richter-Heitmann, Graciana Willis-Poratti, Annika Schnakenberg, Carolin Otersen, Ingrid Dohrmann, Miriam Roemer, Gerhard Bohrmann, Sabine Kasten, Michael W. Friedrich
Summary: This study explored the microbial communities in coastal sediments influenced by increased iron input in permanently cold marine sediments around South Georgia. Results showed that sulfate reduction prevailed in one site, while iron reduction occurred at the others, correlating with distinct microbial communities. The discovery of the previously unrecognized Desulfuromonadales Sva1033 capable of dissimilatory iron reduction highlights the importance of iron and sulfate reduction processes in shaping these microbial communities.
Article
Microbiology
Xiaotian Zhou, Jay T. Lennon, Xiang Lu, Aidong Ruan
Summary: Dam construction has profound impacts on the structure, assembly, and stability of freshwater sediment microbiome, reflecting the ecological and biogeochemical ramifications of human-Earth system interactions. These findings are important for re-examining the formation of sediment microbial stratification.
Article
Microbiology
Javier Vicente, Miguel de Celis, Alejandro Alonso, Domingo Marquina, Antonio Santos
Summary: Deception Island in Antarctica is a geothermal location with active fumaroles, creating a unique habitat for microbial communities. A multidisciplinary study on sediments deposited over 4 years revealed a bacterial community dominated by Proteobacteria and Thaumarchaeota, a fungal community mainly composed of Aspergillaceae, and the presence of diatoms. The study highlighted the significant influence of physicochemical conditions on microbial populations and their distribution, providing valuable data on the interaction between the island and water microbiota.
Article
Environmental Sciences
Jie Lin, Xiaotian Zhou, Xiang Lu, Yaofei Xu, Zhipeng Wei, Aidong Ruan
Summary: This study used a multifractal model to characterize the heterogeneity of sediment grain size and pore space. The results showed that both environmental physiochemistry and microbial community structures varied significantly with depth, with grain size distribution being the key driver of sediment microbial diversity.
ENVIRONMENTAL RESEARCH
(2023)
Article
Environmental Sciences
Mariana Lozada, Maria C. Dieguez, Patricia E. Garcia, Hebe M. Dionisi
Summary: This study found that kelp biomass significantly impacts sediment microbial communities and water chemistry, and the response varies among different algae species and sediment sources. The changes in microbial community structure were closely related to the kelp treatment and, to a lesser extent, to sediment provenance. Additionally, specific microbial populations were enriched in the kelp-amended treatments, indicating niche differentiation in the degradation of different substrates in kelp cell walls. This research expands our knowledge of microbial assemblages in intertidal sediments in response to kelp biomass inputs.
SCIENCE OF THE TOTAL ENVIRONMENT
(2023)
Article
Environmental Sciences
Mark Xavier Bailon, Minoh Park, Kurt Louis Solis, Yeong Na, Dhiraj Kumar Chaudhary, Sungpyo Kim, Yongseok Hong
Summary: This study investigated the mechanisms controlling the reduction of mercury (Hg) bioavailability in activated carbon (AC) amended estuarine sediments. The results showed that AC amendment decreased Hg bioavailability not only through physicochemical sorption, but also by changing geochemical species and shifting the microbial community composition. These findings are important for managing and remediating Hg contaminated sediments.
Article
Environmental Sciences
Yazeed Abdelmageed, Carrie Miller, Carrie Sanders, Timothy Egbo, Alexander Johs, Boakai Robertson
Summary: The study revealed the important role of microbial communities in Hg methylation in contaminated bank soils from East Fork Poplar Creek (EFPC) in Tennessee, USA. By comparing contaminated and uncontaminated soil samples, differences in microbial community composition in different seasons and information about microbial families associated with Hg methylation were identified. These findings provide insights into the biogeochemical drivers of MeHg production and are crucial for future remediation efforts.
WATER AIR AND SOIL POLLUTION
(2021)
Article
Environmental Sciences
Maoyun Yin, Bin Yan, Huan Wang, Yan Wu, Xiang Wang, Jueqiao Wang, Zhihao Zhu, Xixi Yan, Yuting Liu, Meijun Liu, Chuan Fu
Summary: Sediments in freshwater ecosystems serve as long-term sinks for microplastics (MPs) and nutrients. However, little is known about the effects of MPs on nitrogen and phosphorus cycles in these sediments. In this study, PVC, PLA, and PP MPs were added to freshwater sediments, and their effects on microbial communities and nutrient release were evaluated. The results demonstrated that MPs significantly influenced microbial community composition and nutrient cycling in the sediments. PVC and PP MPs promoted microbial nitrification and nitrite oxidation, while PP MPs notably increased alkaline phosphatase (ALP) activity and the abundance of the phosphorus-regulation (phoR) gene. PLA MPs showed potential in increasing the abundance of microbial phosphorus transporter (ugpB), nitrogen fixation (nifD, nifH, and nifX), and denitrification (nirS, napA, and norB) genes, as well as inhibiting nitrification, resulting in the accumulation and release of ammonia nitrogen. Though PLA MPs inhibited ALP activity and the abundance of the organophosphorus mineralization (phoD) gene, they contributed to dissimilatory iron and sulfite reduction, potentially promoting the release of sedimentary phosphorus. This study provides insights into the mechanisms of nitrogen and phosphorus cycles and microbial communities influenced by MPs in sediments, and lays the foundation for future assessments of the environmental behavior of MPs in freshwater ecosystems.
ENVIRONMENTAL POLLUTION
(2023)
Article
Environmental Sciences
Jiang Liu, Jian Liang, Andrea G. Bravo, Shiqiang Wei, Caiyun Yang, Dingyong Wang, Tao Jiang
Summary: The biodegradation of dissolved organic matter in the Three Gorges Reservoir's water-level-fluctuation zone is influenced by different oxygen conditions, with aerobic degradation leading to higher aromaticity and humification of DOM compared to anaerobic degradation. Specific parameters like SUVA (254) and BIX can track DOM biodegradation under anaerobic conditions, while under aerobic conditions, SUVA (254), BIX, and CDOM concentration can be used for tracking, and significant amounts of CDOM can be aerobically biodegraded.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Clelia Calao-Ramos, Andrea G. Bravo, Roberth Paternina-Uribe, Jose Marrugo-Negrete, Sergi Diez
Summary: The study assessed mercury exposure in gold miners in Colombia, finding that burning mercury and fish consumption were significant predictors of mercury exposure. Some miners had mercury concentrations above safe levels set by health organizations, indicating the need for health education programs in certain regions.
ENVIRONMENT INTERNATIONAL
(2021)
Article
Engineering, Environmental
Claudia Cosio, Davide Degli-Esposti, Christine Almunia, Veronique Gaillet, Herve Sartelet, Jean Armengaud, Arnaud Chaumot, Olivier Geffard, Alain Geffard
Summary: The study found that invertebrates fed with methyl-Hg (MeHg) from cell walls of plants had higher concentrations of Hg, potentially triggering different threshold of proteomic response.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Limnology
Eric Capo, Elias Broman, Stefano Bonaglia, Andrea G. Bravo, Stefan Bertilsson, Anne L. Soerensen, Jarone Pinhassi, Daniel Lundin, Moritz Buck, Per O. J. Hall, Francisco J. A. Nascimento, Erik Bjorn
Summary: The expansion of oxygen-deficient zones in marine systems may lead to a compositional change of Hg-methylating microbial groups in sediments, promoting the expansion of Hg methylators whose metabolism and biology have not yet been characterized.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Geography, Physical
Jaap S. Sinninghe Damste, Yuki Weber, Jakob Zopfi, Moritz F. Lehmann, Helge Niemann
Summary: Isoprenoidal glycerol dialkyl glycerol tetraether (isoGDGT) lipids are mainly derived from archaea in the water column of Lake Lugano, Switzerland. The concentration of isoGDGTs, particularly Crenarchaeol, is higher in deeper waters below the thermocline. The distribution of isoGDGTs in surface sediments indicates downward transport from the water between the thermocline and the anoxic hypolimnion. The composition of isoGDGTs in surface sediments of other (peri-)alpine lakes varies based on lake size.
QUATERNARY SCIENCE REVIEWS
(2022)
Review
Chemistry, Analytical
Hugo Baali, Claudia Cosio
Summary: Carbamazepine (CBZ), a common pharmaceutical in the aquatic environment, has various effects on aquatic animals, including ROS homeostasis, neuroendocrine system, cell viability, immunity, reproduction, feeding behavior, and growth. CBZ affects acetylcholinesterase activity at low concentrations and triggers ROS production and cellular stress at higher concentrations. The response to CBZ is species-, organ-, and time-dependent and influenced by experimental conditions and animal origin.
ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS
(2022)
Article
Environmental Sciences
Clement Baratange, Severine Paris-Palacios, Isabelle Bonnard, Laurence Delahaut, Dominique Grandjean, Laurence Wortham, Stephanie Sayen, Andrea Gallorini, Jean Michel, David Renault, Florian Breider, Jean-Luc Loizeau, Claudia Cosio
Summary: In this study, the effects of carbamazepine (CBZ) and mercury (Hg) on zebra mussels were evaluated. It was found that the co-exposure of these two pollutants had the most significant impact, reducing the levels of various metabolites and causing structural changes in cells and organelles. Single exposures to CBZ or Hg had smaller effects, but still resulted in changes in metabolites and cellular structures. Additionally, both single and co-exposures increased the antioxidant response in gills and digestive glands. These findings highlight the importance of considering molecular toxicity pathways in predicting the effects of pollutants on organisms in complex environmental conditions.
ENVIRONMENTAL POLLUTION
(2022)
Article
Engineering, Environmental
Daniel Cossa, Joel Knoery, Daniela Banaru, Mireille Harmelin-Vivien, Jeroen E. Sonke, Ian M. Hedgecock, Andrea G. Bravo, Ginevra Rosati, Donata Canu, Milena Horvat, Francesca Sprovieri, Nicola Pirrone, Lars-Eric Heimburger-Boavida
Summary: Mercury contamination in the Mediterranean, especially in its methylated form, is higher than in other regions of Europe. Methylmercury accounts for a large proportion of the total mercury, and plays a significant role in the supply of mercury to the adjacent North Atlantic Ocean. The concentrations of methylmercury vary in different areas of the Mediterranean, with higher levels associated with low oxygen water masses. This variation is transferred through the food chain and affects the mercury content in top-predatory fish. Monitoring and mitigation strategies are necessary to protect Mediterranean populations from mercury exposure, while still allowing seafood consumption. There are still gaps in our understanding of mercury cycling in the Mediterranean, which requires further research.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Isabel Sanz-Saez, Carla Pereira-Garcia, Andrea G. Bravo, Laura Trujillo, Marti Pla i Ferriol, Miguel Capilla, Pablo Sanchez, Rosa Carmen Rodriguez Martin-Doimeadios, Silvia G. Acinas, Olga Sanchez
Summary: The study reveals the wide distribution and activity of marine bacteria encoding mer genes in the global ocean, with Alteromonas bacteria exhibiting the highest tolerance capacity and efficient degradation ability for MeHg. The prevalence of Alteromonas bacteria in the deep ocean is confirmed, highlighting the importance of biological reductive MeHg degradation in the ocean Hg biogeochemical cycle.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Microbiology
Guangyi Su, Jakob Zopfi, Helge Niemann, Moritz F. Lehmann
Summary: This study has demonstrated the occurrence of anaerobic oxidation of methane (AOM) in the anoxic sediments of Lake Sempach in Switzerland, and identified multiple groups of methanotrophic bacteria and oxidants supporting AOM. However, electron acceptors previously reported to support AOM did not enhance methane turnover in the sediments under anoxic conditions. Addition of oxygen, on the other hand, significantly increased methane oxidation. The study also found that facultative aerobic methanotrophs can grow under anoxic conditions, which has important implications for future investigations on methane oxidation processes.
FRONTIERS IN MICROBIOLOGY
(2022)
Article
Limnology
Jana Tischer, Jakob Zopfi, Claudia Frey, Paul M. Magyar, Andreas Brand, Kirsten Oswald, Corinne Jegge, Caitlin H. Frame, Maria R. Miracle, Xavier Soria-Perpinya, Eduardo Vicente, Moritz F. Lehmann
Summary: This study investigates the pathways of N2O production and reduction in Lake La Cruz, Spain. The results suggest that chemodenitrification induced by the reaction between reactive nitrogen and ferrous iron could contribute to N2O production in the lake. This finding highlights the importance of abiotic processes in N2O emissions from lakes.
LIMNOLOGY AND OCEANOGRAPHY
(2022)
Article
Biochemistry & Molecular Biology
Eric Capo, Benjamin D. Peterson, Minjae Kim, Daniel S. Jones, Silvia G. Acinas, Marc Amyot, Stefan Bertilsson, Erik Bjoern, Moritz Buck, Claudia Cosio, Dwayne A. Elias, Cynthia Gilmour, Marisol Goni-Urriza, Baohua Gu, Heyu Lin, Yu-Rong Liu, Katherine McMahon, John W. Moreau, Jarone Pinhassi, Mircea Podar, Fernando Puente-Sanchez, Pablo Sanchez, Veronika Storck, Yuya Tada, Adrien Vigneron, David A. Walsh, Marine Vandewalle-Capo, Andrea G. Bravo, Caitlin M. Gionfriddo
Summary: Researchers have proposed a standardized protocol for detecting, identifying, and quantifying hgc genes from metagenomes, and have created a database containing information on hgc genes. They have also developed a user-friendly bioinformatic pipeline for accurately characterizing hgc genes from environmental samples. The results show that both approaches have similar efficiency in most environments, except for high diversity environments where the coassembly approach is preferred.
MOLECULAR ECOLOGY RESOURCES
(2023)
Article
Limnology
Maciej Bartosiewicz, Jessica Venetz, Saskia Laeubli, Oscar Sepulveda Steiner, Damien Bouffard, Jakob Zopfi, Moritz F. F. Lehmann
Summary: The study reveals the existence of methane paradox in oxygenated waters of a lake and identifies the factors contributing to the variability in its magnitude. It also suggests that methanogenesis in zooplankton detritus is stimulated through the addition of methylphosphonate.
LIMNOLOGY AND OCEANOGRAPHY
(2023)
Article
Ecology
Guangyi Su, Moritz F. Lehmann, Jana Tischer, Yuki Weber, Fabio Lepori, Jean-Claude Walser, Helge Niemann, Jakob Zopfi
Summary: We investigated the microbial methane oxidation in Lake Lugano, Switzerland. Anaerobic methane oxidation (AOM) coupled to nitrite reduction by Candidatus Methylomirabilis was found in the water column of the meromictic North Basin. However, aerobic methanotrophs prevailed in the more dynamic South Basin and no evidence of nitrite-dependent AOM was found. Our study highlights the importance of physical processes and ecosystem stability in controlling the community composition of aerobic and anaerobic methanotrophs.
Article
Chemistry, Analytical
M. Groeneveld, N. Catalan, K. Einarsdottir, A. G. Bravo, D. N. Kothawala
Summary: This study assesses the stability of fluorescence characteristics of dissolved organic matter (DOM) to differences in solution pH and finds that fluorescence intensity is generally stable within the pH range of 5.5 to 7.5. However, commercial humic substance samples are more sensitive to pH changes.
ANALYTICAL METHODS
(2022)
