Taenzer
Lina
Taenzer
Lina
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ArticleDevelopment of a deep-sea submersible chemiluminescent analyzer for sensing short-lived reactive chemicals(MDPI, 2022-02-22) Taenzer, Lina ; Grabb, Kalina C. ; Kapit, Jason ; Pardis, William A. ; Wankel, Scott D. ; Hansel, Colleen M.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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ThesisDynamics and implications of ROS in marine systems(Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2024-09) Taenzer, Lina ; Hansel, Colleen M. ; Wankel, ScottThe reactive oxygen species (ROS), superoxide and hydrogen peroxide, play critical roles across diverse marine ecosystems, influencing redox chemistry and organismal health. The distribution and concentration of these compounds in the oceans may serve as important controls for various biogeochemical cycles. The contrasting physiological nature of ROS, serving as both integral compounds for cellular processes such as signaling and growth while inducing oxidative cell damage at elevated concentrations, has made interpretation of their roles in organismal and ecosystem health challenging. Despite the potential for these ROS to provide unique insights into the intricate interactions occurring at the interface between life and its surrounding environment, critical gaps in our understanding of these compounds in marine systems exist. In this thesis I explored two aspects of marine ROS. The first part is focused on advancing our understanding of the distribution of superoxide in the sea. As part of a multidisciplinary team, I developed a submersible chemiluminescent sensor (SOLARIS) capable of measuring ROS in situ to ocean depths greater than 4,000 meters. With the use of SOLARIS, I discovered that a broad diversity of sponges and corals are local hotspots of superoxide at depth. Then, I studied the distribution of superoxide in the stratified water column of the Baltic Sea and found large subsurface maxima in the aphotic zone. In the second part of this thesis, I probed the use of hydrogen peroxide as a monitoring agent of organismal health. I measured hydrogen peroxide and bromoform production by two seaweed species exposed to different stressors. An analysis of these signals suggests that hydrogen peroxide could serve as a non-invasive chemical signature for stress in seaweed meadows and farms. Lastly, I characterized hydrogen peroxide associated with different coral species during a Stony Coral Tissue Loss Disease transmission experiment. I determined that hydrogen peroxide does not predict infection before lesions are visible, thus hindering its utility as an early-stage signature of disease within corals. Altogether, this thesis extends our perspective on the distribution and controls on ROS in various marine systems and provides a baseline for using ROS dynamics to monitor organismal health.
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ArticleCorals and sponges are hotspots of reactive oxygen species in the deep sea(National Academy of Sciences, 2023-11-15) Taenzer, Lina ; Wankel, Scott D. ; Kapit, Jason ; Pardis, William A. ; Herrera, Santiago ; Auscavitch, Steven R. ; Grabb, Kalina C. ; Cordes, Erik ; Hansel, Colleen M.Reactive oxygen species (ROS) are central to diverse biological processes through which organisms respond to and interact with their surroundings. Yet, a lack of direct measurements limits our understanding of the distribution of ROS in the ocean. Using a recently developed in situ sensor, we show that deep-sea corals and sponges produce the ROS superoxide, revealing that benthic organisms can be sources and hotspots of ROS production in these environments. These findings confirm previous contentions that extracellular superoxide production by corals can be independent of the activity of photosynthetic symbionts. The discovery of deep-sea corals and sponges as sources of ROS has implications for the physiology and ecology of benthic organisms and introduces a previously overlooked suite of redox reactants at depth.
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ArticleAssessment of hydrogen peroxide as a bioindicator of stress in seaweed aquaculture(Nature Research, 2024-01-23) Taenzer, Lina ; Toth, Gunilla ; Hansel, Colleen M.The rapid expansion in commercial seaweed farming has highlighted the need for more effective monitoring methods, and health diagnostics. The production of the reactive oxygen species (ROS) hydrogen peroxide (H2O2) is a trait that is tied to all major macroalgal groups and holds significance both for its involvement in the oxidative stress response and in the production of climatically relevant gases such as halocarbons. Observations of increased production of H2O2 by plants as a stress response, along with its comparative stability and ease of quantification in seawater in comparison to other ROS, suggest that H2O2 could be used as an indicator of health. In this study we characterized aqueous H2O2 dynamics across a diel cycle, in response to small shifts in light and temperature, as well as when exposed to acute stress. Our results reveal that exposure to acute stressors leads to rapid and sustained concentrations of H2O2 that are orders of magnitude higher than changes in H2O2 concentrations observed throughout the day. These findings provide tantalizing evidence that monitoring H2O2 could be used as a health indicator in seaweed aquaculture and serve as an early warning sign of stress.