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Ge Z, Ma Z, Hong W, Liu K, Yan S, Song W, Zhang J. Temporal variations in reactive oxygen species in biofilms of submerged macrophytes: The key role of microbial metabolism mediated by oxygen fluctuations. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132542. [PMID: 37734308 DOI: 10.1016/j.jhazmat.2023.132542] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/28/2023] [Accepted: 09/11/2023] [Indexed: 09/23/2023]
Abstract
Reactive oxygen species (ROS) play a crucial role in the biogeochemistry of aquatic environments, yet their occurrence and accumulation in the biofilm of submerged macrophytes have been poorly documented. Herein, we first investigated the light-dark cycling fluctuations of biofilm microenvironment and the temporal variations of a representative ROS (O2•-) during biofilm succession on the macrophyte leaves and subsequently quantified the photochemical processes in biofilms. The sustained production of O2•- exhibited a distinct rhythmic fluctuation from 32.49 ± 0.56 μmol/kg to 72.56 ± 0.92 μmol/kg FW, which simultaneously fluctuated with the dissolved oxygen, redox potential, and pH, all driven by the alternating oxic-anoxic conditions of biofilms. The intensities of O2•- and ROS firstly increased and then decreased throughout biofilm succession. The O2•- concentrations in biofilms from different waters followed the order of rural river water > landscape lake water > aquaculture pond water, and the leaf photosynthesis and microbial community played a key role. ROS production was significantly associated with Actinobacteria, Proteobacteria and Bacteroidetes, with contributions of 44.6%, 32.8%, and 15.2%, respectively. Partial least squares path modeling structural equation analysis showed that ROS production in leaf biofilms was mainly related to the microenvironment and microbial metabolism. These findings will facilitate the development of ecological restoration strategies in aquatic environments.
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Affiliation(s)
- Zuhan Ge
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Zihang Ma
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Wenjie Hong
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Kexuan Liu
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Shuwen Yan
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Weihua Song
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China
| | - Jibiao Zhang
- Department of Environmental Science and Engineering, Fudan University, Shanghai 200433, PR China; Shanghai Shifang Ecology and Landscape Co., Ltd, Shanghai 200233, PR China.
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2
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Bowman S. GNOME: A Gaseous Nitrogen Oxide Measuring front-End for aqueous environmental materials. HARDWAREX 2023; 15:e00459. [PMID: 37565173 PMCID: PMC10410601 DOI: 10.1016/j.ohx.2023.e00459] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 06/04/2023] [Accepted: 07/26/2023] [Indexed: 08/12/2023]
Abstract
GNOME is a straightforward and easy to build sample handling apparatus, designed to prepare dissolved nitrogen oxide species in aqueous environmental samples. GNOME is designed to serve as a sample preparation device for downstream chemiluminescent analysis. It is based on the familiar chemistry ring stand; the major advantage scalability designed to accommodate the needs of the user. Additionally, since GNOME is constructed of discrete, snap-to-fit components, the modular design allows users to easily substitute or replace parts. Given that there are few to zero commercial equivalents, construction plans to fill this hardware gap are offered herein. The inlet can resolve down to a lower limit of at least 0.05 nmoles NOX, and is instrumentally linear to a ≥10 nmoles NOX. The approach increases sample throughput, data quality, and overall user experience, making it more efficient than the off-the-shelf commercial equivalent.
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Affiliation(s)
- Samuel Bowman
- Marine Chemistry and Geochemistry Department, Woods Hole Oceanographic Institution, 266 Woods Hole Rd., MS #25, Woods Hole, MA 02543, United States
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3
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Zeng G, Shi M, Dai M, Zhou Q, Luo H, Lin L, Zang K, Meng Z, Pan X. Hydroxyl radicals in natural waters: Light/dark mechanisms, changes and scavenging effects. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 868:161533. [PMID: 36640880 DOI: 10.1016/j.scitotenv.2023.161533] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 01/06/2023] [Accepted: 01/07/2023] [Indexed: 06/17/2023]
Abstract
Hydroxyl radicals (•OH) are the most active, aggressive and oxidative reactive oxygen species. In the natural aquatic environment, •OH plays an important role in the biogeochemistry cycle, biotransformation, and pollution removal. This paper reviewed the distribution and formation mechanism of •OH in aquatic environments, including natural waters, colloidal substances, sediments, and organisms. Furthermore, factors affecting the formation and consumption of •OH were thoroughly discussed, and the mechanisms of •OH generation and scavenging were summarized. In particular, the effects of climate change and artificial work on •OH in the largest natural aquatic environment, i.e., marine environment was analyzed with the help of bibliometrics. Moreover, Fenton reactions make the •OH variation more complicated and should not be neglected, especially in those areas with suspended particles and sediments. Regarding the •OH variation in the natural aquatic environment, more attention should be given to global change and human activities.
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Affiliation(s)
- Ganning Zeng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China; Key Laboratory of Ocean Space Resource Management Technology, MNR, Hangzhou 310012, China
| | - Ming Shi
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Mengzheng Dai
- College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China
| | - Qian Zhou
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Hongwei Luo
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Liangyu Lin
- Key Laboratory of Ocean Space Resource Management Technology, MNR, Hangzhou 310012, China; Zhejiang Academy of Marine Science, Hangzhou 310012, China
| | - Kunpeng Zang
- Zhejiang Carbon Neutral Innovation Institute, Zhejiang University of Technology, Hangzhou 310014, China
| | - Zhu Meng
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China
| | - Xiangliang Pan
- College of Environment, Zhejiang University of Technology, Hangzhou 310014, China.
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Omar NM, Fleury K, Beardsall B, Prášil O, Campbell DA. Genomic capacities for Reactive Oxygen Species metabolism across marine phytoplankton. PLoS One 2023; 18:e0284580. [PMID: 37098087 PMCID: PMC10128935 DOI: 10.1371/journal.pone.0284580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 04/04/2023] [Indexed: 04/26/2023] Open
Abstract
Marine phytoplankton produce and scavenge Reactive Oxygen Species, to support cellular processes, while limiting damaging reactions. Some prokaryotic picophytoplankton have, however, lost all genes encoding scavenging of hydrogen peroxide. Such losses of metabolic function can only apply to Reactive Oxygen Species which potentially traverse the cell membrane outwards, before provoking damaging intracellular reactions. We hypothesized that cell radius influences which elements of Reactive Oxygen Species metabolism are partially or fully dispensable from a cell. We therefore investigated genomes and transcriptomes from diverse marine eukaryotic phytoplankton, ranging from 0.4 to 44 μm radius, to analyze the genomic allocations encoding enzymes metabolizing Reactive Oxygen Species. Superoxide has high reactivity, short lifetimes and limited membrane permeability. Genes encoding superoxide scavenging are ubiquitous across phytoplankton, but the fractional gene allocation decreased with increasing cell radius, consistent with a nearly fixed set of core genes for scavenging superoxide pools. Hydrogen peroxide has lower reactivity, longer intracellular and extracellular lifetimes and readily crosses cell membranes. Genomic allocations to both hydrogen peroxide production and scavenging decrease with increasing cell radius. Nitric Oxide has low reactivity, long intracellular and extracellular lifetimes and readily crosses cell membranes. Neither Nitric Oxide production nor scavenging genomic allocations changed with increasing cell radius. Many taxa, however, lack the genomic capacity for nitric oxide production or scavenging. The probability of presence of capacity to produce nitric oxide decreases with increasing cell size, and is influenced by flagella and colony formation. In contrast, the probability of presence of capacity to scavenge nitric oxide increases with increasing cell size, and is again influenced by flagella and colony formation.
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Affiliation(s)
- Naaman M Omar
- Department of Biology, Mount Allison University, Sackville, NB, Canada
| | - Katherine Fleury
- Department of Biology, Mount Allison University, Sackville, NB, Canada
- Faculty of Veterinary Medicine, University of Calgary, Calgary, AB, Canada
| | - Brian Beardsall
- Department of Biology, Mount Allison University, Sackville, NB, Canada
- Faculty of Computer Science, Dalhousie University, Halifax, NS, Canada
| | - Ondřej Prášil
- Institute of Microbiology, Center Algatech, Laboratory of Photosynthesis, Trebon, CZ, Czech Republic
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Ma Y, Li P, Zhong H, He M, Wang B, Mou X, Wu L. The Ecological Differentiation of Particle-Attached and Free-Living Bacterial Communities in a Seasonal Flooding Lake-the Poyang Lake. MICROBIAL ECOLOGY 2022:10.1007/s00248-022-02134-1. [PMID: 36323973 DOI: 10.1007/s00248-022-02134-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Particle-attached (PA) and free-living (FL) bacterial communities play essential roles in the biogeochemical cycling of essential nutrients in aquatic environments. However, little is known about the factors that drive the differentiation of bacterial lifestyles, especially in flooding lake systems. Here we assessed the compositional and functional similarities between the FL and PA bacterial fractions in a typical flooding lake-the Poyang Lake (PYL) of China. The results revealed that PA communities had significantly different compositions and functions from FL communities in every hydrological period, and the diversity of both PA and FL communities was affected mainly by the water regime rather than bacterial lifestyles. PA communities were more diverse and enriched with Proteobacteria and Bacteroidetes, while FL communities had more Actinobacteria. There was a higher abundance of photosynthetic and nitrogen-cycling bacterial groups in PA communities, but a higher abundance of members involved in hydrocarbon degradation, aromatic hydrocarbon degradation, and methylotrophy in FL communities. Water properties (e.g., temperature, pH, total phosphorus) significantly regulated the lifestyle variations of PA and FL bacteria in PYL. Collectively, our results have demonstrated a clear ecological differentiation of PA and FL bacterial communities in flooding lakes, suggesting that the connectivity between FL and PA bacterial fractions is water property-related rather than water regime-related.
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Affiliation(s)
- Yantian Ma
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China
| | - Pan Li
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China
| | - Hui Zhong
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China
| | - Mengjie He
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China
| | - Binhua Wang
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China
| | - Xiaozhen Mou
- Department of Biological Sciences, Kent State University, Kent, OH, 44242, USA
| | - Lan Wu
- School of Life Science, Key Laboratory of Poyang Lake Environment and Resource Utilization, Ministry of Education, Nanchang University, Nanchang, 330022, China.
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Grabb KC, Pardis WA, Kapit J, Wankel SD, Hayden EB, Hansel CM. Design Optimization of a Submersible Chemiluminescent Sensor (DISCO) for Improved Quantification of Reactive Oxygen Species (ROS) in Surface Waters. SENSORS (BASEL, SWITZERLAND) 2022; 22:6683. [PMID: 36081142 PMCID: PMC9460491 DOI: 10.3390/s22176683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 08/30/2022] [Accepted: 08/31/2022] [Indexed: 06/15/2023]
Abstract
Reactive oxygen species (ROS) are key drivers of biogeochemical cycling while also exhibiting both positive and negative effects on marine ecosystem health. However, quantification of the ROS superoxide (O2-) within environmental systems is hindered by its short half-life. Recently, the development of the diver-operated submersible chemiluminescent sensor (DISCO), a submersible, handheld instrument, enabled in situ superoxide measurements in real time within shallow coral reef ecosystems. Here, we present a redesigned and improved instrument, DISCO II. Similar to the previous DISCO, DISCO II is a self-contained, submersible sensor, deployable to 30 m depth and capable of measuring reactive intermediate species in real time. DISCO II is smaller, lighter, lower cost, and more robust than its predecessor. Laboratory validation of DISCO II demonstrated an average limit of detection in natural seawater of 133.1 pM and a percent variance of 0.7%, with stable photo multiplier tube (PMT) counts, internal temperature, and flow rates. DISCO II can also be optimized for diverse environmental conditions by adjustment of the PMT supply voltage and integration time. Field tests showed no drift in the data with a percent variance of 3.0%. Wand tip adaptations allow for in situ calibrations and decay rates of superoxide using a chemical source of superoxide (SOTS-1). Overall, DISCO II is a versatile, user-friendly sensor that enables measurements in diverse environments, thereby improving our understanding of the cycling of reactive intermediates, such as ROS, across various marine ecosystems.
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Affiliation(s)
- Kalina C. Grabb
- MIT-WHOI Joint Program in Oceanography, Cambridge, MA 02139, USA
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA
| | - William A. Pardis
- Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543, USA
| | - Jason Kapit
- Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543, USA
| | - Scott D. Wankel
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA
| | - Eric B. Hayden
- Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543, USA
| | - Colleen M. Hansel
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA
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Morris JJ, Rose AL, Lu Z. Reactive oxygen species in the world ocean and their impacts on marine ecosystems. Redox Biol 2022; 52:102285. [PMID: 35364435 PMCID: PMC8972015 DOI: 10.1016/j.redox.2022.102285] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 11/17/2022] Open
Abstract
Reactive oxygen species (ROS) are omnipresent in the ocean, originating from both biological (e.g., unbalanced metabolism or stress) and non-biological processes (e.g. photooxidation of colored dissolved organic matter). ROS can directly affect the growth of marine organisms, and can also influence marine biogeochemistry, thus indirectly impacting the availability of nutrients and food sources. Microbial communities and evolution are shaped by marine ROS, and in turn microorganisms influence steady-state ROS concentrations by acting as the predominant sink for marine ROS. Through their interactions with trace metals and organic matter, ROS can enhance microbial growth, but ROS can also attack biological macromolecules, causing extensive modifications with deleterious results. Several biogeochemically important taxa are vulnerable to very low ROS concentrations within the ranges measured in situ, including the globally distributed marine cyanobacterium Prochlorococcus and ammonia-oxidizing archaea of the phylum Thaumarchaeota. Finally, climate change may increase the amount of ROS in the ocean, especially in the most productive surface layers. In this review, we explore the sources of ROS and their roles in the oceans, how the dynamics of ROS might change in the future, and how this change might impact the ecology and chemistry of the future ocean.
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Affiliation(s)
- J Jeffrey Morris
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
| | - Andrew L Rose
- Faculty of Science and Engineering, Southern Cross University, New South Wales, Australia
| | - Zhiying Lu
- Department of Biology, University of Alabama at Birmingham, Birmingham, AL, USA.
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8
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Taenzer L, Grabb K, Kapit J, Pardis W, Wankel SD, Hansel CM. Development of a Deep-Sea Submersible Chemiluminescent Analyzer for Sensing Short-Lived Reactive Chemicals. SENSORS (BASEL, SWITZERLAND) 2022; 22:1709. [PMID: 35270854 PMCID: PMC8914954 DOI: 10.3390/s22051709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/17/2022] [Accepted: 02/19/2022] [Indexed: 06/14/2023]
Abstract
Based on knowledge of their production pathways, and limited discrete observations, a variety of short-lived chemical species are inferred to play active roles in chemical cycling in the sea. In some cases, these species may exert a disproportionate impact on marine biogeochemical cycles, affecting the redox state of metal and carbon, and influencing the interaction between organisms and their environment. One such short-lived chemical is superoxide, a reactive oxygen species (ROS), which undergoes a wide range of environmentally important reactions. Yet, due to its fleeting existence which precludes traditional shipboard analyses, superoxide concentrations have never been characterized in the deep sea. To this end, we have developed a submersible oceanic chemiluminescent analyzer of reactive intermediate species (SOLARIS) to enable continuous measurements of superoxide at depth. Fluidic pumps on SOLARIS combine seawater for analysis with reagents in a spiral mixing cell, initiating a chemiluminescent reaction that is monitored by a photomultiplier tube. The superoxide in seawater is then related to the quantity of light produced. Initial field deployments of SOLARIS have revealed high-resolution trends in superoxide throughout the water column. SOLARIS presents the opportunity to constrain the distributions of superoxide, and any number of chemiluminescent species in previously unexplored environments.
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Affiliation(s)
- Lina Taenzer
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA; (L.T.); (K.G.); (S.D.W.)
- Massachusetts Institute of Technology, Earth, Atmospheric and Planetary Sciences, Cambridge, MA 02139, USA
| | - Kalina Grabb
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA; (L.T.); (K.G.); (S.D.W.)
- Massachusetts Institute of Technology, Earth, Atmospheric and Planetary Sciences, Cambridge, MA 02139, USA
| | - Jason Kapit
- Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543, USA; (J.K.); (W.P.)
| | - William Pardis
- Woods Hole Oceanographic Institution, Applied Ocean Physics and Engineering, Woods Hole, MA 02543, USA; (J.K.); (W.P.)
| | - Scott D. Wankel
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA; (L.T.); (K.G.); (S.D.W.)
| | - Colleen M. Hansel
- Woods Hole Oceanographic Institution, Marine Chemistry and Geochemistry, Woods Hole, MA 02543, USA; (L.T.); (K.G.); (S.D.W.)
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9
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Production of hydrogen peroxide in an intra-meander hyporheic zone at East River, Colorado. Sci Rep 2022; 12:712. [PMID: 35027569 PMCID: PMC8758664 DOI: 10.1038/s41598-021-04171-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 12/03/2021] [Indexed: 11/20/2022] Open
Abstract
The traditionally held assumption that photo-dependent processes are the predominant source of H2O2 in natural waters has been recently questioned by an increrasing body of evidence showing the ubiquitiousness of H2O2 in dark water bodies and in groundwater. In this study, we conducted field measurement of H2O2 in an intra-meander hyporheic zone and in surface water at East River, CO. On-site detection using a sensitive chemiluminescence method suggests H2O2 concentrations in groundwater ranging from 6 nM (at the most reduced region) to ~ 80 nM (in a locally oxygen-rich area) along the intra-meander transect with a maxima of 186 nM detected in the surface water in an early afternoon, lagging the maximum solar irradiance by ∼ 1.5 h. Our results suggest that the dark profile of H2O2 in the hyporheic zone is closely correlated to local redox gradients, indicating that interactions between various redox sensitive elements could play an essential role. Due to its transient nature, the widespread presence of H2O2 in the hyporheic zone indicates the existence of a sustained balance between H2O2 production and consumption, which potentially involves a relatively rapid succession of various biogeochemically important processes (such as organic matter turnover, metal cycling and contaminant mobilization). More importantly, this study confirmed the occurrence of reactive oxygen species at a subsurface redox transition zone and further support our understanding of redox boundaries on reactive oxygen species generation and as key locations of biogeochemical activity.
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Sutherland KM, Ward LM, Colombero CR, Johnston DT. Inter-domain horizontal gene transfer of nickel-binding superoxide dismutase. GEOBIOLOGY 2021; 19:450-459. [PMID: 33989454 DOI: 10.1111/gbi.12448] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/22/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
The ability of aerobic microorganisms to regulate internal and external concentrations of the reactive oxygen species (ROS) superoxide directly influences the health and viability of cells. Superoxide dismutases (SODs) are the primary regulatory enzymes that are used by microorganisms to degrade superoxide. SOD is not one, but three separate, non-homologous enzymes that perform the same function. Thus, the evolutionary history of genes encoding for different SOD enzymes is one of convergent evolution, which reflects environmental selection brought about by an oxygenated atmosphere, changes in metal availability, and opportunistic horizontal gene transfer (HGT). In this study, we examine the phylogenetic history of the protein sequence encoding for the nickel-binding metalloform of the SOD enzyme (SodN). The genomic potential to produce SodN is widespread among bacteria, including Actinobacteriota (Actinobacteria), Chloroflexota (Chloroflexi), Cyanobacteria, Proteobacteria, Patescibacteria, and others. The gene is also present in many archaea, with Thermoplasmatota and Nanoarchaeota representing the vast majority of archaeal sodN diversity. A comparison of organismal and SodN protein phylogenetic trees reveals several instances of HGT, including multiple inter-domain transfers of the sodN gene from the bacterial domain to the archaeal domain. Nearly half of the archaeal members with sodN live in the photic zone of the marine water column. The sodN gene is widespread and characterized by apparent vertical gene transfer in some sediment- or soil-associated lineages within the Actinobacteriota and Chloroflexota phyla, suggesting the ancestral sodN likely originated in one of these clades before expanding its taxonomic and biogeographic distribution to additional microbial groups in the surface ocean in response to decreasing iron availability. In addition to decreasing iron quotas, nickel-binding SOD has the added benefit of withstanding high reactant and product ROS concentrations without damaging the enzyme, making it particularly well suited for the modern surface ocean.
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Affiliation(s)
- K M Sutherland
- Department of Earth and Planetary Science, Harvard University, Cambridge, MA, USA
| | - L M Ward
- Department of Earth and Planetary Science, Harvard University, Cambridge, MA, USA
| | - C-R Colombero
- Department of Earth and Planetary Science, Harvard University, Cambridge, MA, USA
| | - D T Johnston
- Department of Earth and Planetary Science, Harvard University, Cambridge, MA, USA
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