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Bognár Z, Mosshammer M, Brodersen KE, Bollati E, Gyurcsányi RE, Kühl M. Multiparameter Sensing of Oxygen and pH at Biological Interfaces via Hyperspectral Imaging of Luminescent Sensor Nanoparticles. ACS Sens 2024; 9:1763-1774. [PMID: 38607997 PMCID: PMC11060167 DOI: 10.1021/acssensors.3c01941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 03/22/2024] [Accepted: 03/29/2024] [Indexed: 04/14/2024]
Abstract
Chemical dynamics in biological samples are seldom stand-alone processes but represent the outcome of complicated cascades of interlinked reaction chains. In order to understand these processes and how they correlate, it is important to monitor several parameters simultaneously at high spatial and temporal resolution. Hyperspectral imaging is a promising tool for this, as it provides broad-range spectral information in each pixel, enabling the use of multiple luminescent indicator dyes, while simultaneously providing information on sample structures and optical properties. In this study, we first characterized pH- and O2-sensitive indicator dyes incorporated in different polymer matrices as optical sensor nanoparticles to provide a library for (hyperspectral) chemical imaging. We then demonstrate the successful combination of a pH-sensitive indicator dye (HPTS(DHA)3), an O2-sensitive indicator dye (PtTPTBPF), and two reference dyes (perylene and TFPP), incorporated in polymer nanoparticles for multiparameter chemical imaging of complex natural samples such as green algal biofilms (Chlorella sorokiniana) and seagrass leaves (Zostera marina) with high background fluorescence. We discuss the system-specific challenges and limitations of our approach and further optimization possibilities. Our study illustrates how multiparameter chemical imaging with hyperspectral read-out can now be applied on natural samples, enabling the alignment of several chemical parameters to sample structures.
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Affiliation(s)
- Zsófia Bognár
- BME
“Lendület” Chemical Nanosensors Research Group,
Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest 1111, Hungary
- Center
for Visualizing Catalytic Processes (VISION), Department of Physics, Technical University of Denmark, Fysikvej 307, Kongens Lyngby 2800, Denmark
| | - Maria Mosshammer
- Marine
Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingo̷r 3000, Denmark
| | - Kasper E. Brodersen
- Marine
Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingo̷r 3000, Denmark
- Environmental
Dynamics, Department of Science and Environment, Roskilde University, Universitetsvej 1, Roskilde 4000, Denmark
| | - Elena Bollati
- Marine
Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingo̷r 3000, Denmark
| | - Róbert E. Gyurcsányi
- BME
“Lendület” Chemical Nanosensors Research Group,
Department of Inorganic and Analytical Chemistry, Budapest University of Technology and Economics, Műegyetem rkp. 3, Budapest 1111, Hungary
- HUN-REN-BME
Computation Driven Chemistry Research Group, Department of Inorganic
and Analytical Chemistry, Budapest University
of Technology and Economics, Műegyetem rkp. 3, Budapest 1111, Hungary
| | - Michael Kühl
- Marine
Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, Helsingo̷r 3000, Denmark
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Brodersen KE, Mosshammer M, Bittner MJ, Hallstrøm S, Santner J, Riemann L, Kühl M. Seagrass-mediated rhizosphere redox gradients are linked with ammonium accumulation driven by diazotrophs. Microbiol Spectr 2024; 12:e0333523. [PMID: 38426746 PMCID: PMC10986515 DOI: 10.1128/spectrum.03335-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 01/24/2024] [Indexed: 03/02/2024] Open
Abstract
Seagrasses can enhance nutrient mobilization in their rhizosphere via complex interactions with sediment redox conditions and microbial populations. Yet, limited knowledge exists on how seagrass-derived rhizosphere dynamics affect nitrogen cycling. Using optode and gel-sampler-based chemical imaging, we show that radial O2 loss (ROL) from rhizomes and roots leads to the formation of redox gradients around below-ground tissues of seagrass (Zostera marina), which are co-localized with regions of high ammonium concentrations in the rhizosphere. Combining such chemical imaging with fine-scale sampling for microbial community and gene expression analyses indicated that multiple biogeochemical pathways and microbial players can lead to high ammonium concentration within the oxidized regions of the seagrass rhizosphere. Symbiotic N2-fixing bacteria (Bradyrhizobium) were particularly abundant and expressed the diazotroph functional marker gene nifH in Z. marina rhizosphere areas with high ammonium concentrations. Such an association between Z. marina and Bradyrhizobium can facilitate ammonium mobilization, the preferred nitrogen source for seagrasses, enhancing seagrass productivity within nitrogen-limited environments. ROL also caused strong gradients of sulfide at anoxic/oxic interfaces in rhizosphere areas, where we found enhanced nifH transcription by sulfate-reducing bacteria. Furthermore, we found a high abundance of methylotrophic and sulfide-oxidizing bacteria in rhizosphere areas, where O2 was released from seagrass rhizomes and roots. These bacteria could play a beneficial role for the plants in terms of their methane and sulfide oxidation, as well as their formation of growth factors and phytohormones. ROL from below-ground tissues of seagrass, thus, seems crucial for ammonium production in the rhizosphere via stimulation of multiple diazotrophic associations. IMPORTANCE Seagrasses are important marine habitats providing several ecosystem services in coastal waters worldwide, such as enhancing marine biodiversity and mitigating climate change through efficient carbon sequestration. Notably, the fitness of seagrasses is affected by plant-microbe interactions. However, these microscale interactions are challenging to study and large knowledge gaps prevail. Our study shows that redox microgradients in the rhizosphere of seagrass select for a unique microbial community that can enhance the ammonium availability for seagrass. We provide first experimental evidence that Rhizobia, including the symbiotic N2-fixing bacteria Bradyrhizobium, can contribute to the bacterial ammonium production in the seagrass rhizosphere. The release of O2 from rhizomes and roots also caused gradients of sulfide in rhizosphere areas with enhanced nifH transcription by sulfate-reducing bacteria. O2 release from seagrass root systems thus seems crucial for ammonium production in the rhizosphere via stimulation of multiple diazotrophic associations.
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Affiliation(s)
| | - Maria Mosshammer
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Meriel J. Bittner
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Søren Hallstrøm
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Jakob Santner
- Department of Crop Sciences, Institute of Agronomy, University of Natural Resources and Life Sciences Vienna, Tulln an der Donau, Austria
| | - Lasse Riemann
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
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Paul AA, Aladese AD, Marks RS. Additive Manufacturing Applications in Biosensors Technologies. BIOSENSORS 2024; 14:60. [PMID: 38391979 PMCID: PMC10887193 DOI: 10.3390/bios14020060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2023] [Revised: 01/18/2024] [Accepted: 01/20/2024] [Indexed: 02/24/2024]
Abstract
Three-dimensional (3D) printing technology, also known as additive manufacturing (AM), has emerged as an attractive state-of-the-art tool for precisely fabricating functional materials with complex geometries, championing several advancements in tissue engineering, regenerative medicine, and therapeutics. However, this technology has an untapped potential for biotechnological applications, such as sensor and biosensor development. By exploring these avenues, the scope of 3D printing technology can be expanded and pave the way for groundbreaking innovations in the biotechnology field. Indeed, new printing materials and printers would offer new possibilities for seamlessly incorporating biological functionalities within the growing 3D scaffolds. Herein, we review the additive manufacturing applications in biosensor technologies with a particular emphasis on extrusion-based 3D printing modalities. We highlight the application of natural, synthetic, and composite biomaterials as 3D-printed soft hydrogels. Emphasis is placed on the approach by which the sensing molecules are introduced during the fabrication process. Finally, future perspectives are provided.
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Affiliation(s)
- Abraham Abbey Paul
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel;
| | - Adedamola D. Aladese
- Department of Physics and Material Science, University of Memphis, Memphis, TN 38152, USA;
| | - Robert S. Marks
- Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel;
- Ilse Katz Centre for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be’er Sheva 84105, Israel
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Wang T, Liao C, Jiang Z, Wang J, Ma Y, Lin H, Zhang Y, Lv H, Zhang X, Hu Y, Yang Y, Zhou G. Ratiometric fluorescent sensor with large pseudo-Stokes shifts for precise sensing and imaging of pH without interferential background fluorescence. Talanta 2024; 266:125041. [PMID: 37556950 DOI: 10.1016/j.talanta.2023.125041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/31/2023] [Accepted: 08/04/2023] [Indexed: 08/11/2023]
Abstract
Endowing fluorescent pH sensors with large Stokes shifts promises to resolve interferential background fluorescence in practice, and yet few such method has been reported, owing to lack of luminescent materials with large Stokes shifts used in fluorescent sensors. Herein, we elaborately designed NaGdF4:Ce@NaGdF4:Nd@NaYF4:Eu core-double shells (CDS) lanthanide-doped fluoride nanoparticles (LFNPs), employing Gd3+-mediated energy migration and interfacial energy transfer to realize intense red and NIR emissions under 254 nm irradiation, and pseudo-Stokes shifts of which reached up to striking 361 nm and 610 nm, respectively. The CDS LFNPs collaborated with absorption-based pH indicator bromocresol green to from a novel fluorescent sensor film, and employing low-cost dual chip RGB-NIR camera to precisely record luminescence signals. On the basis of inner-filter effects, this senor system enabled accurate ratiometric read-out of pH value ranging from 5 to 6 (pKa ± 0.5), according to intensity ratios of pH-sensitive red emissions and referenced NIR emissions, avoiding common errors (e.g., fluctuant light sources). Notably, the large pseudo-Stokes shifts allowed red and NIR emissions far from the interfering background fluorescence possessing relatively small Stokes shifts, ensuring elevated signal-to-noise ratio and accurate pH determination. Therefore, the devised pH sensor system based on the CDS LFNPs exhibited sufficient accuracy in autofluorescent real samples (e.g., algae, serum), revealing a novel way of employing large pseudo-Stokes shifts to realize the background-free pH measurement and 2D imaging.
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Affiliation(s)
- Tao Wang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Chuan Liao
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, PR China
| | - Zike Jiang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China.
| | - Jing Wang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Yanyan Ma
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China.
| | - Haitao Lin
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Yimeng Zhang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Hongmin Lv
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Xiaonan Zhang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Yimeng Hu
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Yingdong Yang
- Institute of Oceanographic Instrumentation, Qilu University of Technology (Shandong Academy of Sciences), Shandong Provincial Key Laboratory of Marine Monitoring Instrument Equipment Technology, National Engineering and Technological Research Center of Marine Monitoring Equipment, Qingdao 266061, PR China
| | - Guangjun Zhou
- State Key Laboratory of Crystal Materials, Shandong University, Jinan, 250100, PR China.
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Lin J, Sun Y, Zhang H, Shen Q, Xu L, Zeng Q, Su Y, Han C. Two-dimensional, high-resolution imaging of pH dynamics in the phyllosphere of submerged macrophyte using a new Nano-optode. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166327. [PMID: 37595908 DOI: 10.1016/j.scitotenv.2023.166327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 08/20/2023]
Abstract
The phyllosphere pH helps shape the plant microbiome and strongly influences aboveground interactions in plant canopies. Yet little is known about the distribution of pH at a microscale within the macrophyte phyllosphere and the factors promoting them because achieving high-resolution quantitative imaging of phyllosphere pH is a great challenge. Here, new ratiometric pH nano-optodes were prepared by firstly encapsulating the self-synthesized lipophilic dyes (8-acetoxypyrene-N1, N3, N6-trioctadecyl-1, 3, 6-tri-trisulfonamide) to poly(1-vinylpyrrolidone-co-styrene) nanoparticles, and then immobilizing the resulting nanoparticles in polyurethane hydrogel on transparent foils. The nano-optodes presented reversible and fast response (t95 < 80 s) to the pH range from 7.0 to 11.0, with merits of good spatial resolution, photobleaching/leaching resistance and negligible cross-sensitives toward temperature, O2 and ionic strength (< 100 mM). The nano-optodes together with a self-designed phyllosphere chamber were further applied to directly measure the pH distributions at a microscale around single leaves of V. spiralis grown in natural sediment. The pronounced pH microheterogeneity and leaf basification within the V. spiralis phyllosphere were quantitatively visualized. We also provided direct empirical evidence that the dynamic of the phyllosphere pH at high resolution was significantly controlled by the shifting light intensity and temperature. Implementation of the nano-optodes holds great potential for various laboratory applications, which will provide an in-depth insight into phyllosphere activities on the microscale.
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Affiliation(s)
- Jianyu Lin
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yu Sun
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Hao Zhang
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - Qiushi Shen
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Li Xu
- Institute of Quality Standard and Testing Technology, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China
| | - Qingfei Zeng
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Yaling Su
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
| | - Chao Han
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China.
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He Y, Ding N, Yu G, Sunahara GI, Lin H, Zhang X, Ullah H, Liu J. High-resolution imaging of O 2 dynamics and metal solubilization in the rhizosphere of the hyperaccumulator Leersia hexandra Swartz. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131580. [PMID: 37167872 DOI: 10.1016/j.jhazmat.2023.131580] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Revised: 04/25/2023] [Accepted: 05/03/2023] [Indexed: 05/13/2023]
Abstract
The mobilization of trace metals in the rhizosphere can be affected by the redox potential, which is closely related to the O2 dynamics. This study examined the distributions of O2 and trace metals in the rhizosphere of the subaquatic hyperaccumulator Leersia hexandra Swartz under chromium (Cr) stress using planar optodes and the diffusive gradients in thin films technique coupled with laser ablation inductively coupled plasma mass spectrometry. The O2 concentrations and oxidized areas in the rhizosphere significantly increased with increases in the light intensity, air humidity, and atmospheric CO2 concentrations (p < 0.05). The O2 concentration first increased with increasing ambient temperatures, then decreased when the temperature increased from 25 to 32 ℃. The O2 concentration in the rhizosphere was significantly decreased under Cr stress (p < 0.05), with a prolonged response time to the altered ambient temperature. Cr stress led to decreased mobilities of As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Sb, V, W, and Zn in the rhizosphere, which were negatively correlated with the concentrations of O2. These results provide new insights into the role of changes in the O2 concentration induced by the roots of hyperaccumulator plants in controlling the mobility of trace metals in soils.
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Affiliation(s)
- Yao He
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China
| | - Na Ding
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China
| | - Guo Yu
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China.
| | - Geoffrey I Sunahara
- Department of Natural Resource Sciences, McGill University, Montreal, Quebec, Canada
| | - Hua Lin
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China.
| | - Xuehong Zhang
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China
| | - Habib Ullah
- Department of Environmental Science, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jie Liu
- College of Environmental Science and Engineering, Guilin University of Technology, Guilin, China; Guangxi Collaborative Innovation Center for Water Pollution Control and Water Safety in Karst Areas, Guilin University of Technology, 541000 Guilin, China
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Brazel AJ, Graciet E. Complexity of Abiotic Stress Stimuli: Mimicking Hypoxic Conditions Experimentally on the Basis of Naturally Occurring Environments. Methods Mol Biol 2023; 2642:23-48. [PMID: 36944871 DOI: 10.1007/978-1-0716-3044-0_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Plants require oxygen to respire and produce energy. Plant cells are exposed to low oxygen levels (hypoxia) in different contexts and have evolved conserved molecular responses to hypoxia. Both environmental and developmental factors can influence intracellular oxygen concentrations. In nature, plants can experience hypoxic conditions when the soil becomes saturated with water following heavy precipitation (i.e., waterlogging). Hypoxia can also arise in specific tissues that have poor gas exchange with atmospheric oxygen. In this case, hypoxic niches that are physiologically and developmentally relevant may form. To dissect the molecular mechanisms underlying the regulation of hypoxia response in plants, a wide range of hypoxia-inducing methods have been used in the laboratory setting. Yet, the different characteristics, pros and cons of each of these hypoxia treatments are seldom compared between methods, and with natural forms of hypoxia. In this chapter, we present both environmental and developmental forms of hypoxia that plants encounter in the wild, as well as the different experimental hypoxia treatments used to mimic them in the laboratory setting, with the aim of informing on what experimental approaches might be most appropriate to the questions addressed, including stress signaling and regulation.
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Soonthornkalump S, Ow YX, Saewong C, Buapet P. Comparative study on anatomical traits and gas exchange responses due to belowground hypoxic stress and thermal stress in three tropical seagrasses. PeerJ 2022; 10:e12899. [PMID: 35186485 PMCID: PMC8840093 DOI: 10.7717/peerj.12899] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 01/17/2022] [Indexed: 01/11/2023] Open
Abstract
BACKGROUND The ability to maintain sufficient oxygen levels in the belowground tissues and the rhizosphere is crucial for the growth and survival of seagrasses in habitats with highly reduced sediment. Such ability varies depending on plant anatomical features and environmental conditions. METHODS In the present study, we compared anatomical structures of roots, rhizomes and leaves of the tropical intertidal seagrasses, Cymodocea rotundata, Thalassia hemprichii and Halophila ovalis, followed by an investigation of their gas exchange both in the belowground and aboveground tissues and photosynthetic electron transport rates (ETR) in response to experimental manipulations of O2 level (normoxia and root hypoxia) and temperature (30 °C and 40 °C). RESULTS We found that C. rotundata and T. hemprichii displayed mostly comparable anatomical structures, whereas H. ovalis displayed various distinctive features, including leaf porosity, number and size of lacunae in roots and rhizomes and structure of radial O2 loss (ROL) barrier. H. ovalis also showed unique responses to root hypoxia and heat stress. Root hypoxia increased O2 release from belowground tissues and overall photosynthetic activity of H. ovalis but did not affect the other two seagrasses. More pronounced warming effects were detected in H. ovalis, measured as lower O2 release in the belowground tissues and overall photosynthetic capacity (O2 release and dissolved inorganic carbon uptake in the light and ETR). High temperature inhibited photosynthesis of C. rotundata and T. hemprichii but did not affect their O2 release in belowground tissues. Our data show that seagrasses inhabiting the same area respond differently to root hypoxia and temperature, possibly due to their differences in anatomical and physiological attributes. Halophila ovalis is highly dependent on photosynthesis and appears to be the most sensitive species with the highest tendency of O2 loss in hypoxic sediment. At the same time, its root oxidation capacity may be compromised under warming scenarios.
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Affiliation(s)
- Sutthinut Soonthornkalump
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand,Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Yan Xiang Ow
- St John’s Island National Marine Laboratory, Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
| | - Chanida Saewong
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand,Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Pimchanok Buapet
- Division of Biological Science, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla, Thailand,Coastal Oceanography and Climate Change Research Center, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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Zhou W, Dong J, Ding D, Long L, Suo A, Lin X, Yang Q, Lin L, Zhang Y, Ling J. Rhizosphere microbiome dynamics in tropical seagrass under short-term inorganic nitrogen fertilization. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2021; 28:19021-19033. [PMID: 33394400 DOI: 10.1007/s11356-020-12048-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 12/09/2020] [Indexed: 06/12/2023]
Abstract
Rhizosphere microbes are crucial to seagrass meadows because they promote plant growth and heath. However, information concerning the response of rhizosphere microorganisms in seagrass sediment in the presence of different nitrogen sources is lacking. Here, by means of high-throughput sequencing, we investigated how addition of inorganic nitrogen affects the rhizosphere microbiome of the tropical seagrass Thalassia hemperichii. A seagrass culture system was set up to conduct a nitrogen addition (ammonium and nitrate) simulation experiment. We found that the relative abundance of Proteobacteria and Bacteroidetes was increased in inorganic nitrogen-enriched samples, whereas that of Acidobacteria decreased under ammonium enrichment, especially after 35 days. High levels of inorganic nitrogen addition caused a significant decrease in the relative abundance of Desulfobacteraceae, Sulfurovaceae, and Spirochaetes, which are primarily involved in sulfur cycling. Additionally, the abundance of microbes in the seagrass rhizosphere reached the highest after the ammonium-enrichment treatment. Among the analyzed seagrass photosynthetic characteristics, seagrass leaves presented the highest light utility in treatments receiving nitrate, followed by the control groups and ammonium-enrichment groups. Moreover, 16S rRNA gene-predicted functional analysis suggested that some functions related to metabolism of amino acids and signal transduction were enriched in samples receiving high ammonium, whereas nitrate addition enriched predicted functions related to diseases. These findings provide new insights into the response of microbial communities to different types of nitrogen additions in seagrass ecosystems.
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Affiliation(s)
- Weiguo Zhou
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
| | - Junde Dong
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China
| | - Dewen Ding
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
| | - Lijuan Long
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
| | - Anning Suo
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
| | - Xiancheng Lin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Qingsong Yang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China
| | - Liyun Lin
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
| | - Yanying Zhang
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China
- Tropical Marine Biological Research Station in Hainan, Chinese Academy of Sciences, Sanya, 572000, China
| | - Juan Ling
- CAS Key Laboratory of Tropical Marine Bio-Resources and Ecology, Guangdong Provincial Key Laboratory of Applied Marine Biology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, 510301, China.
- Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, 511458, Guangdong Province, China.
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10
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Steinegger A, Wolfbeis OS, Borisov SM. Optical Sensing and Imaging of pH Values: Spectroscopies, Materials, and Applications. Chem Rev 2020; 120:12357-12489. [PMID: 33147405 PMCID: PMC7705895 DOI: 10.1021/acs.chemrev.0c00451] [Citation(s) in RCA: 181] [Impact Index Per Article: 45.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Indexed: 12/13/2022]
Abstract
This is the first comprehensive review on methods and materials for use in optical sensing of pH values and on applications of such sensors. The Review starts with an introduction that contains subsections on the definition of the pH value, a brief look back on optical methods for sensing of pH, on the effects of ionic strength on pH values and pKa values, on the selectivity, sensitivity, precision, dynamic ranges, and temperature dependence of such sensors. Commonly used optical sensing schemes are covered in a next main chapter, with subsections on methods based on absorptiometry, reflectometry, luminescence, refractive index, surface plasmon resonance, photonic crystals, turbidity, mechanical displacement, interferometry, and solvatochromism. This is followed by sections on absorptiometric and luminescent molecular probes for use pH in sensors. Further large sections cover polymeric hosts and supports, and methods for immobilization of indicator dyes. Further and more specific sections summarize the state of the art in materials with dual functionality (indicator and host), nanomaterials, sensors based on upconversion and 2-photon absorption, multiparameter sensors, imaging, and sensors for extreme pH values. A chapter on the many sensing formats has subsections on planar, fiber optic, evanescent wave, refractive index, surface plasmon resonance and holography based sensor designs, and on distributed sensing. Another section summarizes selected applications in areas, such as medicine, biology, oceanography, bioprocess monitoring, corrosion studies, on the use of pH sensors as transducers in biosensors and chemical sensors, and their integration into flow-injection analyzers, microfluidic devices, and lab-on-a-chip systems. An extra section is devoted to current challenges, with subsections on challenges of general nature and those of specific nature. A concluding section gives an outlook on potential future trends and perspectives.
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Affiliation(s)
- Andreas Steinegger
- Institute
of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
| | - Otto S. Wolfbeis
- Institute
of Analytical Chemistry, Chemo- and Biosensors, University of Regensburg, D-93040 Regensburg, Germany
| | - Sergey M. Borisov
- Institute
of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010 Graz, Austria
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11
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Fang J, Yang R, Cao Q, Dong J, Li C, Quan Q, Huang M, Liu J. Differences of the microbial community structures and predicted metabolic potentials in the lake, river, and wetland sediments in Dongping Lake Basin. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2020; 27:19661-19677. [PMID: 32221828 DOI: 10.1007/s11356-020-08446-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 03/16/2020] [Indexed: 06/10/2023]
Abstract
In freshwater ecosystems, wetlands are generally distinguished from deep-water ecosystems by 2-m water level as boundary. However, the difference of sediment microbial communities between wetlands and deep-water ecosystems is still unclear. We combined 16S rRNA gene sequencing and community metabolic prediction to compare sediment microbial communities and predicted metabolic genes of wetlands (natural and constructed wetlands) and deep-water ecosystems (river and lake) along with environmental factors in summer and autumn in Dongping Lake Basin. Results showed that the deep-water ecosystems had significantly higher community richness than the wetlands in autumn in the freshwater basin, which was mostly related to the pH of sediments. However, no significant difference in community richness was found in summer. Besides, the composition of both predicted metabolic genes and microbial communities was significantly affected by dissolved organic carbon (DOC) and dissolved oxygen (DO). The wetlands exhibited high predicted gene abundances related to xenobiotic biodegradation possibly due to the high DOC or DO level. Compared with the wetlands, most of the deep-water ecosystems exhibited high predicted gene abundances related to element (carbon, nitrogen, and sulfur) metabolism possibly due to the low DOC and DO levels in the freshwater basin. This study can expand the knowledge of ecological function distribution and detoxification mechanism of microbial communities in freshwater ecosystems.
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Affiliation(s)
- Jiaohui Fang
- Environmental Research Institute, Shandong University, Qingdao, 266237, China
| | - Ruirui Yang
- Environmental Research Institute, Shandong University, Qingdao, 266237, China
| | - Qingqing Cao
- School of Architecture and Urban Planning, Shandong Jianzhu University, Jinan, 250101, China
| | - Junyu Dong
- Environmental Research Institute, Shandong University, Qingdao, 266237, China
| | - Changchao Li
- Environmental Research Institute, Shandong University, Qingdao, 266237, China
| | - Quan Quan
- State Key Laboratory of Eco-hydraulics in Northwest Arid Region of China, Xi'an University of Technology, Xi'an, 710048, China
| | - Miansong Huang
- Ningxia Capital Sponge City Construction & Development Co., Ltd, Guyuan, 756000, China
| | - Jian Liu
- Environmental Research Institute, Shandong University, Qingdao, 266237, China.
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12
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Hales S, Tokita E, Neupane R, Ghosh U, Elder B, Wirthlin D, Kong YL. 3D printed nanomaterial-based electronic, biomedical, and bioelectronic devices. NANOTECHNOLOGY 2020; 31:172001. [PMID: 31805540 DOI: 10.1088/1361-6528/ab5f29] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The ability to seamlessly integrate functional materials into three-dimensional (3D) constructs has been of significant interest, as it can enable the creation of multifunctional devices. Such integration can be achieved with a multiscale, multi-material 3D printing strategy. This technology has enabled the creation of unique devices such as personalized tissue regenerative scaffolds, biomedical implants, 3D electronic devices, and bionic constructs which are challenging to realize with conventional manufacturing processes. In particular, the incorporation of nanomaterials into 3D printed devices can endow a wide range of constructs with tailorable mechanical, chemical, and electrical functionalities. This review highlights the advances and unique possibilities in the fabrication of novel electronic, biomedical, and bioelectronic devices that are realized by the synergistic integration of nanomaterials with 3D printing technologies.
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Affiliation(s)
- Samuel Hales
- Department of Mechanical Engineering, University of Utah, Salt Lake City, UT 84112, United States of America
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13
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Kankanamge NR, Bennett WW, Teasdale PR, Huang J, Welsh DT. A new colorimetric DET technique for determining mm-resolution sulfide porewater distributions and allowing improved interpretation of iron(II) co-distributions. CHEMOSPHERE 2020; 244:125388. [PMID: 31809928 DOI: 10.1016/j.chemosphere.2019.125388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/13/2019] [Accepted: 11/14/2019] [Indexed: 06/10/2023]
Abstract
Measurement of sulfide in pore waters is critical for understanding biogeochemical processes, especially within coastal sediments. Here we report the development of a new colorimetric DET (diffusive equilibration in thin films) technique for determining mm-resolution, two-dimensional sulfide distributions in sediment pore waters. This colorimetric sulfide DET method was based on the standard spectrophotometric methylene blue assay, but modified to allow quantitation of sulfide by computer imaging densitometry. The method detection and effective upper measurement limits of the optimised technique were 3.7 and 1000 μmol L-1, respectively. The optimised sulfide DET method was combined with the colorimetric iron(II) DET method to obtain co-distributions in coastal seagrass (Zostera muelleri) colonised sediment under light and dark conditions. In the dark, seagrass sediments were more reduced than in the light, with large areas being dominated by high porewater sulfide concentrations. These co-distributions were compared with those obtained using the previously described DET-DGT (diffusive gradients in thin films) method for measuring iron(II) and sulfide co-distributions. There was less overlap of iron(II) and sulfide distributions using the sulfide DET as the two DET methods are influenced most by the later hours of deployment, whereas the sulfide-DGT measurement integrates concentrations over the whole deployment period. Overlap was most apparent in very dynamic sediment zones, such as burrow wall sediments.
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Affiliation(s)
- Nadeeka Rathnayake Kankanamge
- Environmental Futures Research Institute and Griffith School of Environment, Griffith University, Gold Coast Campus, QLD, 4215, Australia; Earth and Ocean Sciences, School of Natural Sciences and Ryan Institute, National University of Ireland, Galway, H91 TK33, Ireland
| | - William W Bennett
- Environmental Futures Research Institute and Griffith School of Environment, Griffith University, Gold Coast Campus, QLD, 4215, Australia
| | - Peter R Teasdale
- Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, SA, 5095, Australia; Future Industries Institute, University of South Australia, SA, 5095, Australia
| | - Jianyin Huang
- Natural and Built Environments Research Centre, School of Natural and Built Environments, University of South Australia, SA, 5095, Australia; Future Industries Institute, University of South Australia, SA, 5095, Australia
| | - David T Welsh
- Environmental Futures Research Institute and Griffith School of Environment, Griffith University, Gold Coast Campus, QLD, 4215, Australia.
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14
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Brodersen KE, Koren K, Revsbech NP, Kühl M. Strong leaf surface basification and CO 2 limitation of seagrass induced by epiphytic biofilm microenvironments. PLANT, CELL & ENVIRONMENT 2020; 43:174-187. [PMID: 31429088 DOI: 10.1111/pce.13645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Revised: 08/07/2019] [Accepted: 08/09/2019] [Indexed: 06/10/2023]
Abstract
Coastal eutrophication is a growing problem worldwide, leading to increased epiphyte overgrowth of seagrass leaves. Yet little is known about how epiphytes affect key biogeochemical conditions and processes in the seagrass phyllosphere. We used electrochemical microsensors to measure microgradients of O2 , pH, and CO2 at the bare and epiphyte-covered leaf surface of seagrass (Zostera marina L.) to determine effects of epiphytes on the leaf chemical microenvironment. Epiphytes result in extreme daily fluctuations in pH, O2 , and inorganic carbon concentrations at the seagrass leaf surface severely hampering the plant's performance. In light, leaf epiphyte biofilms and their diffusive boundary layer lead to strong basification, markedly reducing the CO2 and HCO3- availability at the leaf surface, leading to reduced photosynthetic efficiency as a result of carbon limitation and enhanced photorespiration. With epiphytes, leaf surface pH increased to >10, thereby exceeding final pH levels (~9.62) and CO2 compensation points for active photosynthesis. In darkness, epiphyte biofilms resulted in increased CO2 and hypoxia at the leaf surface. Epiphytes can lead to severe carbon limitation in seagrasses owing to strong phyllosphere basification leading to CO2 depletion and costly, yet limiting, HCO3- utilization, increasing the risk of plant starvation.
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Affiliation(s)
| | - Klaus Koren
- Department of Bioscience, Aarhus University Centre for Water Technology, Aarhus C, Denmark
| | - Niels Peter Revsbech
- Department of Bioscience, Aarhus University Centre for Water Technology, Aarhus C, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
- Climate Change Cluster, Faculty of Science, University of Technology Sydney, Sydney, Australia
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15
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Nielsen SD, Paegle I, Borisov SM, Kjeldsen KU, Røy H, Skibsted J, Koren K. Optical Sensing of pH and O 2 in the Evaluation of Bioactive Self-Healing Cement. ACS OMEGA 2019; 4:20237-20243. [PMID: 31815225 PMCID: PMC6893957 DOI: 10.1021/acsomega.9b02541] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/31/2019] [Indexed: 05/08/2023]
Abstract
Leakage from cementitious structures with a retaining function can have devastating environmental consequences. Leaks can originate from cracks within the hardened cementitious material that is supposed to seal the structure off from the surrounding environment. Bioactive self-healing concretes containing bacteria capable of microbially inducing CaCO3 precipitation have been suggested to mitigate the healing of such cracks before leaking occurs. An important parameter determining the biocompatibility of concretes and cements is the pH environment. Therefore, a novel ratiometric pH optode imaging system based on an inexpensive single-lens reflex (SLR) camera was used to characterize the pH of porewater within cracks of submerged hydrated oil and gas well cement. This enabled the imaging of pH with a spatial distribution in high resolution (50 μm per pixel) and a gradient of 1.4 pH units per 1 mm. The effect of fly ash substitution and hydration time on the pH of the cement surface was evaluated by this approach. The results show that pH is significantly reduced from pH >11 to below 10 with increasing fly ash content as well as hydration time. The assessment of bioactivity in the cement was evaluated by introducing superabsorbent polymers with encapsulated Bacillus alkalinitrilicus endospores into the cracks. The bacterial activity was measured using oxygen optodes, which showed the highest bacterial activity with increasing amounts of fly ash substitution in the cement, correlating with the decrease in the pH. Overall, our results demonstrate that the pH of well cements can be reliably measured and modified to sustain the microbial activity.
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Affiliation(s)
- Søren Dollerup Nielsen
- Center
for Geomicrobiology, Aarhus University Centre for Water Technology,
Section for Microbiology, Department of Bioscience, and Department of Chemistry and Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
- E-mail: (S.D.N.)
| | - Ieva Paegle
- Department
of Civil Engineering, Technical University
of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Sergey M. Borisov
- Institute
of Analytical Chemistry and Food Chemistry, Graz University of Technology, 8010 Graz, Austria
| | - Kasper Urup Kjeldsen
- Center
for Geomicrobiology, Aarhus University Centre for Water Technology,
Section for Microbiology, Department of Bioscience, and Department of Chemistry and Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
| | - Hans Røy
- Center
for Geomicrobiology, Aarhus University Centre for Water Technology,
Section for Microbiology, Department of Bioscience, and Department of Chemistry and Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
| | - Jørgen Skibsted
- Center
for Geomicrobiology, Aarhus University Centre for Water Technology,
Section for Microbiology, Department of Bioscience, and Department of Chemistry and Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
| | - Klaus Koren
- Center
for Geomicrobiology, Aarhus University Centre for Water Technology,
Section for Microbiology, Department of Bioscience, and Department of Chemistry and Interdisciplinary
Nanoscience Center (iNANO), Aarhus University, 8000 Aarhus, Denmark
- E-mail: (K.K.)
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16
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Constraints on CaCO3 precipitation in superabsorbent polymer by aerobic bacteria. Appl Microbiol Biotechnol 2019; 104:365-375. [DOI: 10.1007/s00253-019-10215-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/08/2019] [Accepted: 10/22/2019] [Indexed: 10/25/2022]
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17
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Koren K, Moßhammer M, Scholz VV, Borisov SM, Holst G, Kühl M. Luminescence Lifetime Imaging of Chemical Sensors-A Comparison between Time-Domain and Frequency-Domain Based Camera Systems. Anal Chem 2019; 91:3233-3238. [PMID: 30758940 DOI: 10.1021/acs.analchem.8b05869] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Luminescence lifetime based imaging is still the most reliable method for generating chemical images using chemical sensor technology. However, only few commercial systems are available that enable imaging lifetimes within the relevant nanosecond to microsecond range. In this technical note we compare the performance of an older time-domain (TD) based camera system with a frequency-domain (FD) based camera system regarding their measuring characteristics and applicability for O2 and pH imaging in environmental samples and with different indicator dye systems emitting in the visible and near-infrared part of the spectrum. We conclude that the newly introduced FD imaging system delivers comparable if not better results than its predecessor, now enabling robust and simple chemical imaging based on FD luminescence lifetime measurements.
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Affiliation(s)
- Klaus Koren
- Aarhus University Centre for Water Technology, Section for Microbiology, Department of Bioscience , Aarhus University , Ny Munkegade , DK-8000 Aarhus C , Denmark
| | - Maria Moßhammer
- Marine Biological Section, Department of Biology , University of Copenhagen , Strandpromenaden 5 , DK-3000 Helsingør , Denmark
| | - Vincent V Scholz
- Center for Electromicrobiology , Aarhus University , DK-8000 Aarhus , Denmark
| | - Sergey M Borisov
- Institute of Analytical Chemistry and Food Chemistry , Graz University of Technology , Stremayrgasse 9 , AT-8010 Graz , Austria
| | | | - Michael Kühl
- Marine Biological Section, Department of Biology , University of Copenhagen , Strandpromenaden 5 , DK-3000 Helsingør , Denmark.,Climate Change Cluster , University of Technology Sydney , Ultimo , NSW 2007 , Australia
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18
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Moßhammer M, Brodersen KE, Kühl M, Koren K. Nanoparticle- and microparticle-based luminescence imaging of chemical species and temperature in aquatic systems: a review. Mikrochim Acta 2019; 186:126. [PMID: 30680465 DOI: 10.1007/s00604-018-3202-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Accepted: 12/20/2018] [Indexed: 11/25/2022]
Abstract
Most aquatic systems rely on a multitude of biogeochemical processes that are coupled with each other in a complex and dynamic manner. To understand such processes, minimally invasive analytical tools are required that allow continuous, real-time measurements of individual reactions in these complex systems. Optical chemical sensors can be used in the form of fiber-optic sensors, planar sensors, or as micro- and nanoparticles (MPs and NPs). All have their specific merits, but only the latter allow for visualization and quantification of chemical gradients over 3D structures. This review (with 147 references) summarizes recent developments mainly in the field of optical NP sensors relevant for chemical imaging in aquatic science. The review encompasses methods for signal read-out and imaging, preparation of NPs and MPs, and an overview of relevant MP/NP-based sensors. Additionally, examples of MP/NP-based sensors in aquatic systems such as corals, plant tissue, biofilms, sediments and water-sediment interfaces, marine snow and in 3D bioprinting are given. We also address current challenges and future perspectives of NP-based sensing in aquatic systems in a concluding section. Graphical abstract ᅟ.
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Affiliation(s)
- Maria Moßhammer
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark
| | - Kasper Elgetti Brodersen
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark
| | - Michael Kühl
- Marine Biological Section, Department of Biology, University of Copenhagen, 3000, Helsingør, Denmark.
- Climate Change Cluster, University of Technology Sydney, Ultimo, NSW, 2007, Australia.
| | - Klaus Koren
- Aarhus University Center for Water Technology, Department of Bioscience - Microbiology, Aarhus University, 8000, Aarhus, Denmark.
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19
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In Vitro Community Synergy between Bacterial Soil Isolates Can Be Facilitated by pH Stabilization of the Environment. Appl Environ Microbiol 2018; 84:AEM.01450-18. [PMID: 30143509 DOI: 10.1128/aem.01450-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 08/19/2018] [Indexed: 01/01/2023] Open
Abstract
The composition and development of naturally occurring microbial communities are defined by a complex interplay between the community and the surrounding environment and by interactions between community members. Intriguingly, these interactions can in some cases cause synergies, where the community is able to outperform its single-species constituents. However, the underlying mechanisms driving community interactions are often unknown and difficult to identify due to high community complexity. Here, we show how opposite pH drift induced by specific community members leads to pH stabilization of the microenvironment, acting as a positive interspecies interaction, driving in vitro community synergy in a model consortium of four coisolated soil bacteria, Microbacterium oxydans, Xanthomonas retroflexus, Stenotrophomonas rhizophila, and Paenibacillus amylolyticus We use microsensor pH measurements to show how individual species change the local pH microenvironment and how cocultivation leads to a stabilized pH regime over time. Specifically, in vitro acid production from P. amylolyticus and alkali production primarily from X. retroflexus led to an overall pH stabilization of the local environment over time, which in turn resulted in enhanced community growth. This specific type of interspecies interaction was found to be highly dependent on medium type and concentration; however, similar pH drift from the individual species could be observed across medium variants.IMPORTANCE Understanding interspecies interactions in bacterial communities is important for unraveling species dynamics in naturally occurring communities. These dynamics are fundamental for identifying evolutionary drivers and for the development of efficient biotechnological industry applications. Recently, pH interplay among community members has been identified as a factor affecting community development, and pH stabilization has been demonstrated to result in enhanced community growth. The use of model communities in which the effect of changing pH level can be attributed to specific species contributes to the investigation of community developmental drivers. This contributes to assessment of the extent of emergent behavior and members' contributions to community development. Here, we show that pH stabilization of the microenvironment in vitro in a synthetic coisolated model community results in synergistic growth. This observation adds to the growing diversity of community interactions leading to enhanced community growth and hints toward pH as a strong driver for community development in diverse environments.
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20
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Han C, Ren J, Wang Z, Yang S, Ke F, Xu D, Xie X. Characterization of phosphorus availability in response to radial oxygen losses in the rhizosphere of Vallisneria spiralis. CHEMOSPHERE 2018; 208:740-748. [PMID: 29902758 DOI: 10.1016/j.chemosphere.2018.05.180] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2018] [Revised: 05/23/2018] [Accepted: 05/29/2018] [Indexed: 06/08/2023]
Abstract
The viewpoint that radial oxygen loss (ROL) of submerged macrophytes induces changes in redox conditions and the associated phosphorus (P) availability has been indirectly confirmed at larger spatial scales using conventional, destructive techniques. However, critical information about microniches has largely been overlooked due to the lack of satisfactory in situ mapping technologies. In this study, we deployed a recently developed hybrid sensor in the rhizosphere of Vallisneria spiralis (V. spiralis) during two vegetation periods to provide 2-D imaging of the spatiotemporal co-distribution of oxygen (O2) and P from a fixed observation point. Overall, the images of O2 and P showed a high degree of spatiotemporal heterogeneity throughout the rhizosphere at the sub-mm scale. A clear decrease in the P mobilization corresponded well to the steep O2 enhancement within a 2-mm-thick zone around younger V. spiralis root, indicating a significant coupling relationship between ROL and P availability. Surprisingly, despite significant diurnal shifts in ROL along the older V. spiralis roots, P availability did not fluctuate in a substantial part of the rhizosphere throughout the day; however, ROL increased the P immobilization significantly by changing the redox gradients at the outer rhizosphere. This study clearly demonstrates how continuous ROL of V. spiralis can play a major role in regulating P availability within the rhizosphere. The premise behind this statement is the discovery of how this continuous ROL can lead to the formation of three distinctive redox landscapes in the rooting sediment (oxic, suboxic, or anaerobic layers).
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Affiliation(s)
- Chao Han
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Jinghua Ren
- Geological Survey of Jiangsu Province, Nanjing, 210018, China
| | - Zhaode Wang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China.
| | - Shika Yang
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Fan Ke
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Di Xu
- State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xianchuan Xie
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210093, China.
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21
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Brodersen KE, Siboni N, Nielsen DA, Pernice M, Ralph PJ, Seymour J, Kühl M. Seagrass rhizosphere microenvironment alters plant-associated microbial community composition. Environ Microbiol 2018; 20:2854-2864. [PMID: 29687545 DOI: 10.1111/1462-2920.14245] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2017] [Revised: 04/12/2018] [Accepted: 04/14/2018] [Indexed: 11/26/2022]
Abstract
The seagrass rhizosphere harbors dynamic microenvironments, where plant-driven gradients of O2 and dissolved organic carbon form microhabitats that select for distinct microbial communities. To examine how seagrass-mediated alterations of rhizosphere geochemistry affect microbial communities at the microscale level, we applied 16S rRNA amplicon sequencing of artificial sediments surrounding the meristematic tissues of the seagrass Zostera muelleri together with microsensor measurements of the chemical conditions at the basal leaf meristem (BLM). Radial O2 loss (ROL) from the BLM led to ∼ 300 µm thick oxic microzones, wherein pronounced decreases in H2 S and pH occurred. Significantly higher relative abundances of sulphate-reducing bacteria were observed around the meristematic tissues compared to the bulk sediment, especially around the root apical meristems (RAM; ∼ 57% of sequences). Within oxic microniches, elevated abundances of sulphide-oxidizing bacteria were observed compared to the bulk sediment and around the RAM. However, sulphide oxidisers within the oxic microzone did not enhance sediment detoxification, as rates of H2 S re-oxidation here were similar to those observed in a pre-sterilized root/rhizome environment. Our results provide novel insights into how chemical and microbiological processes in the seagrass rhizosphere modulate plant-microbe interactions potentially affecting seagrass health.
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Affiliation(s)
- Kasper Elgetti Brodersen
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia.,Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Nachshon Siboni
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia
| | - Daniel A Nielsen
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia
| | - Mathieu Pernice
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia
| | - Peter J Ralph
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia
| | - Justin Seymour
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia
| | - Michael Kühl
- Climate Change Cluster, Faculty of Science, University of Technology Sydney (UTS), Sydney, NSW, Australia.,Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
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22
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Schrameyer V, York PH, Chartrand K, Ralph PJ, Kühl M, Brodersen KE, Rasheed MA. Contrasting impacts of light reduction on sediment biogeochemistry in deep- and shallow-water tropical seagrass assemblages (Green Island, Great Barrier Reef). MARINE ENVIRONMENTAL RESEARCH 2018; 136:38-47. [PMID: 29472034 DOI: 10.1016/j.marenvres.2018.02.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 01/31/2018] [Accepted: 02/11/2018] [Indexed: 06/08/2023]
Abstract
Seagrass meadows increasingly face reduced light availability as a consequence of coastal development, eutrophication, and climate-driven increases in rainfall leading to turbidity plumes. We examined the impact of reduced light on above-ground seagrass biomass and sediment biogeochemistry in tropical shallow- (∼2 m) and deep-water (∼17 m) seagrass meadows (Green Island, Australia). Artificial shading (transmitting ∼10-25% of incident solar irradiance) was applied to the shallow- and deep-water sites for up to two weeks. While above-ground biomass was unchanged, higher diffusive O2 uptake (DOU) rates, lower O2 penetration depths, and higher volume-specific O2 consumption (R) rates were found in seagrass-vegetated sediments as compared to adjacent bare sand (control) areas at the shallow-water sites. In contrast, deep-water sediment characteristics did not differ between bare sand and vegetated sites. At the vegetated shallow-water site, shading resulted in significantly lower hydrogen sulphide (H2S) levels in the sediment. No shading effects were found on sediment biogeochemistry at the deep-water site. Overall, our results show that the sediment biogeochemistry of shallow-water (Halodule uninervis, Syringodium isoetifolium, Cymodocea rotundata and C. serrulata) and deep-water (Halophila decipiens) seagrass meadows with different species differ in response to reduced light. The light-driven dynamics of the sediment biogeochemistry at the shallow-water site could suggest the presence of a microbial consortium, which might be stimulated by photosynthetically produced exudates from the seagrass, which becomes limited due to lower seagrass photosynthesis under shaded conditions.
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Affiliation(s)
- Verena Schrameyer
- Climate Change Cluster, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Paul H York
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, QLD, Australia
| | - Kathryn Chartrand
- Climate Change Cluster, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, QLD, Australia
| | - Peter J Ralph
- Climate Change Cluster, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia
| | - Michael Kühl
- Climate Change Cluster, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark
| | - Kasper Elgetti Brodersen
- Climate Change Cluster, School of Life Sciences, University of Technology Sydney, Sydney, NSW, Australia; Marine Biological Section, Department of Biology, University of Copenhagen, Helsingør, Denmark.
| | - Michael A Rasheed
- Centre for Tropical Water & Aquatic Ecosystem Research, James Cook University, Cairns, QLD, Australia
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23
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Campbell ML, Heppenstall LD, Hendry R, Martin R, Sørensen S, Rubenstein AN, Hewitt CL. Niche partitioning of intertidal seagrasses: evidence of the influence of substrate temperature. THE NEW PHYTOLOGIST 2018; 217:1449-1462. [PMID: 29238982 DOI: 10.1111/nph.14944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 11/09/2017] [Indexed: 06/07/2023]
Abstract
The influence of soil temperature on rhizome depths of four intertidal seagrass species was investigated in central Queensland, Australia. We postulated that certain intertidal seagrass species are soil temperature-sensitive and vertically stratify rhizome depths. Below-ground vertical stratification of intertidal seagrass rhizome depths was analysed based upon microclimate (soil temperature) and microhabitat (soil type). Soil temperature profiles exhibited heat transfer from surface layers to depth that varied by microhabitat, with vertical stratification of rhizome depths between species. Halodule uninervis rhizomes maintain a narrow median soil temperature envelope; compensating for high surface temperatures by occupying deeper, cooler soil substrates. Halophila decipiens, Halophila ovalis and Zostera muelleri rhizomes are shallow-rooted and exposed to fluctuating temperatures, with broader median temperature envelopes. Halodule uninervis appears to be a niche specialist, with the two Halophila species considered as generalist niche usage species. The implications of niche use based upon soil temperature profiles and rhizome rooting depths are discussed in the context of species' thermal tolerances and below-ground biomass O2 demand associated with respiration and maintenance of oxic microshields. This preliminary evidence suggests that soil temperature interaction with rhizome rooting depths may be a factor that influences the distribution of intertidal seagrasses.
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Affiliation(s)
- Marnie L Campbell
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Medical and Applied Science, Central Queensland University, Bryan Jordan Drive, Gladstone, Qld, 4680, Australia
| | - Lara D Heppenstall
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Rebecca Hendry
- School of Medical and Applied Science, Central Queensland University, Bryan Jordan Drive, Gladstone, Qld, 4680, Australia
| | - Ross Martin
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Stine Sørensen
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Ashley N Rubenstein
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
| | - Chad L Hewitt
- The Environmental Research Institute, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
- School of Science, University of Waikato, Private Bag 3105, Hamilton, 3240, New Zealand
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24
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Sønderholm M, Koren K, Wangpraseurt D, Jensen PØ, Kolpen M, Kragh KN, Bjarnsholt T, Kühl M. Tools for studying growth patterns and chemical dynamics of aggregated Pseudomonas aeruginosa exposed to different electron acceptors in an alginate bead model. NPJ Biofilms Microbiomes 2018; 4:3. [PMID: 29479470 PMCID: PMC5818519 DOI: 10.1038/s41522-018-0047-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 01/07/2018] [Accepted: 01/24/2018] [Indexed: 12/31/2022] Open
Abstract
In chronic infections, bacterial pathogens typically grow as small dense cell aggregates embedded in a matrix consisting of, e.g., wound bed sludge or lung mucus. Such biofilm growth mode exhibits extreme tolerance towards antibiotics and the immune defence system. The bacterial aggregates are exposed to physiological heterogeneity and O2 limitation due to steep chemical gradients through the matrix, which is are hypothesised to contribute to antibiotic tolerance. Using a novel combination of microsensor and bioimaging analysis, we investigated growth patterns and chemical dynamics of the pathogen Pseudomonas aeruginosa in an alginate bead model, which mimics growth in chronic infections better than traditional biofilm experiments in flow chambers. Growth patterns were strongly affected by electron acceptor availability and the presence of chemical gradients, where the combined presence of O2 and nitrate yielded highest bacterial growth by combined aerobic respiration and denitrification.
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Affiliation(s)
- Majken Sønderholm
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Klaus Koren
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
| | - Daniel Wangpraseurt
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Peter Østrup Jensen
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Mette Kolpen
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Kasper Nørskov Kragh
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
| | - Thomas Bjarnsholt
- Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, DK-2200 Copenhagen N, Denmark
- Department of Clinical Microbiology 9301, Copenhagen University Hospital, Rigshospitalet, Juliane Maries Vej 22, Copenhagen, Denmark
| | - Michael Kühl
- Marine Biology Section, Department of Biology, University of Copenhagen, Strandpromenaden 5, DK-3000 Helsingør, Denmark
- Climate Change Cluster, University of Technology Sydney, Broadway, NSW 2007 Australia
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25
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Brodersen K, Koren K, Moßhammer M, Ralph PJ, Kühl M, Santner J. Seagrass-Mediated Phosphorus and Iron Solubilization in Tropical Sediments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:14155-14163. [PMID: 29149570 PMCID: PMC5738630 DOI: 10.1021/acs.est.7b03878] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Revised: 10/17/2017] [Accepted: 11/17/2017] [Indexed: 05/24/2023]
Abstract
Tropical seagrasses are nutrient-limited owing to the strong phosphorus fixation capacity of carbonate-rich sediments, yet they form densely vegetated, multispecies meadows in oligotrophic tropical waters. Using a novel combination of high-resolution, two-dimensional chemical imaging of O2, pH, iron, sulfide, calcium, and phosphorus, we found that tropical seagrasses are able to mobilize the essential nutrients iron and phosphorus in their rhizosphere via multiple biogeochemical pathways. We show that tropical seagrasses mobilize phosphorus and iron within their rhizosphere via plant-induced local acidification, leading to dissolution of carbonates and release of phosphate, and via local stimulation of microbial sulfide production, causing reduction of insoluble Fe(III) oxyhydroxides to dissolved Fe(II) with concomitant phosphate release into the rhizosphere porewater. These nutrient mobilization mechanisms have a direct link to seagrass-derived radial O2 loss and secretion of dissolved organic carbon from the below-ground tissue into the rhizosphere. Our demonstration of seagrass-derived rhizospheric phosphorus and iron mobilization explains why seagrasses are widely distributed in oligotrophic tropical waters.
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Affiliation(s)
- Kasper
Elgetti Brodersen
- Climate
Change Cluster, Faculty of Science, University
of Technology Sydney (UTS), Sydney 2007, New South Wales, Australia
- Marine
Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Klaus Koren
- Marine
Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Maria Moßhammer
- Marine
Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Peter J. Ralph
- Climate
Change Cluster, Faculty of Science, University
of Technology Sydney (UTS), Sydney 2007, New South Wales, Australia
| | - Michael Kühl
- Climate
Change Cluster, Faculty of Science, University
of Technology Sydney (UTS), Sydney 2007, New South Wales, Australia
- Marine
Biological Section, Department of Biology, University of Copenhagen, DK-3000 Helsingør, Denmark
| | - Jakob Santner
- Division
of Agronomy, Department of Crop SciencesUniversity of Natural Resources and Life Sciences, Vienna, 3430 Tulln an der Donau, Austria
- Rhizosphere
Ecology and Biogeochemistry Group, Institute of Soil Research, Department
of Forest and Soil Sciences, University
of Natural Resources and Life Sciences, Vienna, 3430 Tulln an der Donau, Austria
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26
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Design and Fabrication of a Ratiometric Planar Optode for Simultaneous Imaging of pH and Oxygen. SENSORS 2017; 17:s17061316. [PMID: 28590430 PMCID: PMC5492042 DOI: 10.3390/s17061316] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/09/2017] [Revised: 05/10/2017] [Accepted: 05/27/2017] [Indexed: 11/27/2022]
Abstract
This paper presents a simple, high resolution imaging approach utilizing ratiometric planar optode for simultaneous measurement of dissolved oxygen (DO) and pH. The planar optode comprises a plastic optical film coated with oxygen indicator Platinum(II) octaethylporphyrin (PtOEP) and reference quantum dots (QDs) embedded in polystyrene (PS), pH indicator 5-Hexadecanoylamino-fluorescein (5-Fluorescein) embedded in Hydromed D4 matrix. The indicator and reference dyes are excited by utilizing an LED (Light Emitting Diode) source with a central wavelength of 405 nm, the emission respectively matches the different channels (red, green, and blue) of a 3CCD camera after eliminating the excitation source by utilizing the color filter. The result shows that there is low cross-sensitivity between the two analytes dissolved oxygen and pH, and it shows good performance in the dynamic response ranges of 0–12 mg/L and a dynamic range of pH 6−8. The optode has been tested with regard to the response times, accuracy, photostability and stability. The applied experiment for detecting pH/Oxygen of sea-water under the influence of the rain drops is demonstrated. It is shown that the planar optode measuring system provides a simple method with low cross-talk for pH/Oxygen imaging in aqueous applications.
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27
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Brodersen KE, Hammer KJ, Schrameyer V, Floytrup A, Rasheed MA, Ralph PJ, Kühl M, Pedersen O. Sediment Resuspension and Deposition on Seagrass Leaves Impedes Internal Plant Aeration and Promotes Phytotoxic H 2S Intrusion. FRONTIERS IN PLANT SCIENCE 2017; 8:657. [PMID: 28536583 PMCID: PMC5423392 DOI: 10.3389/fpls.2017.00657] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2016] [Accepted: 04/10/2017] [Indexed: 05/11/2023]
Abstract
HIGHLIGHTS: Sedimentation of fine sediment particles onto seagrass leaves severely hampers the plants' performance in both light and darkness, due to inadequate internal plant aeration and intrusion of phytotoxic H2S. Anthropogenic activities leading to sediment re-suspension can have adverse effects on adjacent seagrass meadows, owing to reduced light availability and the settling of suspended particles onto seagrass leaves potentially impeding gas exchange with the surrounding water. We used microsensors to determine O2 fluxes and diffusive boundary layer (DBL) thickness on leaves of the seagrass Zostera muelleri with and without fine sediment particles, and combined these laboratory measurements with in situ microsensor measurements of tissue O2 and H2S concentrations. Net photosynthesis rates in leaves with fine sediment particles were down to ~20% of controls without particles, and the compensation photon irradiance increased from a span of 20-53 to 109-145 μmol photons m-2 s-1. An ~2.5-fold thicker DBL around leaves with fine sediment particles impeded O2 influx into the leaves during darkness. In situ leaf meristematic O2 concentrations of plants exposed to fine sediment particles were lower than in control plants and exhibited long time periods of complete meristematic anoxia during night-time. Insufficient internal aeration resulted in H2S intrusion into the leaf meristematic tissues when exposed to sediment resuspension even at relatively high night-time water-column O2 concentrations. Fine sediment particles that settle on seagrass leaves thus negatively affect internal tissue aeration and thereby the plants' resilience against H2S intrusion.
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Affiliation(s)
- Kasper E. Brodersen
- Climate Change Cluster, Faculty of Science, University of Technology SydneySydney, NSW, Australia
- *Correspondence: Kasper E. Brodersen
| | - Kathrine J. Hammer
- Freshwater Biological Laboratory, Department of Biology, University of CopenhagenCopenhagen, Denmark
| | - Verena Schrameyer
- Climate Change Cluster, Faculty of Science, University of Technology SydneySydney, NSW, Australia
| | - Anja Floytrup
- Freshwater Biological Laboratory, Department of Biology, University of CopenhagenCopenhagen, Denmark
| | - Michael A. Rasheed
- Centre for Tropical Water and Aquatic Ecosystem Research (TropWater), James Cook UniversityCairns, QLD, Australia
| | - Peter J. Ralph
- Climate Change Cluster, Faculty of Science, University of Technology SydneySydney, NSW, Australia
| | - Michael Kühl
- Climate Change Cluster, Faculty of Science, University of Technology SydneySydney, NSW, Australia
- Marine Biological Section, Department of Biology, University of CopenhagenHelsingør, Denmark
| | - Ole Pedersen
- Freshwater Biological Laboratory, Department of Biology, University of CopenhagenCopenhagen, Denmark
- School of Plant Biology, The University of Western AustraliaCrawley, WA, Australia
- Ole Pedersen
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