scholarly journals Carbon limitation leads to thermodynamic regulation of aerobic metabolism

2020 ◽  
Author(s):  
Vanessa A. Garayburu-Caruso ◽  
James C. Stegen ◽  
Hyun-Seob Song ◽  
Lupita Renteria ◽  
Jaqueline Wells ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Biogeochemical Cycles ◽  
Freshwater Ecosystems ◽  
Aerobic Respiration ◽  
Carbon Limitation ◽  
New Paradigm ◽  
Ultrahigh Resolution ◽  
Respiration Rates ◽  
Biogeochemical Models ◽  
Global Biogeochemical Cycles

AbstractOrganic matter (OM) metabolism in freshwater ecosystems is a critical source of uncertainty in global biogeochemical cycles, yet aquatic OM cycling remains poorly understood. Here, we present the first work to explicitly test OM thermodynamics as a key regulator of aerobic respiration, challenging long-held beliefs that organic carbon and oxygen concentrations are the primary determinants of respiration rates. We pair controlled microcosm experiments with ultrahigh-resolution OM characterization to demonstrate a clear relationship between OM thermodynamic favorability and aerobic respiration under carbon limitation. We also demonstrate a shift in the regulation of aerobic respiration from OM thermodynamics to nitrogen content when carbon is in excess, highlighting a central role for OM thermodynamics in aquatic biogeochemical cycling particularly in carbon-limited ecosystems. Our work therefore illuminates a structural gap in aquatic biogeochemical models and presents a new paradigm in which OM thermodynamics and nitrogen content interactively govern aerobic respiration.

scholarly journals Bioturbation enhances the aerobic respiration of lake sediments in warming lakes

2016 ◽  
Vol 12 (8) ◽  
pp. 20160448 ◽  
Author(s):  
Viktor Baranov ◽  
Jörg Lewandowski ◽  
Stefan Krause
Keyword(s):  
Lake Sediment ◽  
Carbon Metabolism ◽  
Seasonal Changes ◽  
Biogeochemical Cycles ◽  
Aerobic Respiration ◽  
Sediment Respiration ◽  
The Earth ◽  
Global Biogeochemical Cycles ◽  
The Impact ◽  
Benthic Animals

While lakes occupy less than 2% of the total surface of the Earth, they play a substantial role in global biogeochemical cycles. For instance, shallow lakes are important sites of carbon metabolism. Aerobic respiration is one of the important drivers of the carbon metabolism in lakes. In this context, bioturbation impacts of benthic animals (biological reworking of sediment matrix and ventilation of the sediment) on sediment aerobic respiration have previously been underestimated. Biological activity is likely to change over the course of a year due to seasonal changes of water temperatures. This study uses microcosm experiments to investigate how the impact of bioturbation (by Diptera, Chironomidae larvae) on lake sediment respiration changes when temperatures increase. While at 5°C, respiration in sediments with and without chironomids did not differ, at 30°C sediment respiration in microcosms with 2000 chironomids per m 2 was 4.9 times higher than in uninhabited sediments. Our results indicate that lake water temperature increases could significantly enhance lake sediment respiration, which allows us to better understand seasonal changes in lake respiration and carbon metabolism as well as the potential impacts of global warming.

scholarly journals Redox-informed models of global biogeochemical cycles

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Emily J. Zakem ◽  
Martin F. Polz ◽  
Michael J. Follows
Keyword(s):  
Climate Change ◽  
Microbial Activity ◽  
First Principles ◽  
Biogeochemical Cycles ◽  
Ecological Interactions ◽  
Climate Change Projections ◽  
Global Models ◽  
Biogeochemical Models ◽  
Georgia O'keefe ◽  
Global Biogeochemical Cycles

Abstract Microbial activity mediates the fluxes of greenhouse gases. However, in the global models of the marine and terrestrial biospheres used for climate change projections, typically only photosynthetic microbial activity is resolved mechanistically. To move forward, we argue that global biogeochemical models need a theoretically grounded framework with which to constrain parameterizations of diverse microbial metabolisms. Here, we explain how the key redox chemistry underlying metabolisms provides a path towards this goal. Using this first-principles approach, the presence or absence of metabolic functional types emerges dynamically from ecological interactions, expanding model applicability to unobserved environments. “Nothing is less real than realism. It is only by selection, by elimination, by emphasis, that we get at the real meaning of things.” –Georgia O’Keefe

scholarly journals Special Issue “Anaerobes in Biogeochemical Cycles”

2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Caroline M. Plugge ◽  
Diana Z. Sousa
Keyword(s):  
Essential Role ◽  
Biogeochemical Cycles ◽  
Special Issue ◽  
Anaerobic Microorganisms ◽  
Global Biogeochemical Cycles

Anaerobic microorganisms, Bacteria and Archaea, have an essential role in global biogeochemical cycles [...]

scholarly journals Meet the Editor: Global Biogeochemical Cycles

Eos ◽  
2005 ◽  
Vol 86 (44) ◽  
pp. 434
Author(s):  
Mohi Kumar
Keyword(s):  
Biogeochemical Cycles ◽  
Global Biogeochemical Cycles

scholarly journals Virus-mediated archaeal hecatomb in the deep seafloor

2016 ◽  
Vol 2 (10) ◽  
pp. e1600492 ◽  
Author(s):  
Roberto Danovaro ◽  
Antonio Dell’Anno ◽  
Cinzia Corinaldesi ◽  
Eugenio Rastelli ◽  
Ricardo Cavicchioli ◽  
...  
Keyword(s):  
Viral Infection ◽  
Deep Sea ◽  
Viral Infections ◽  
Biogeochemical Cycles ◽  
Global Scale ◽  
Viral Lysis ◽  
Group I ◽  
Global Biogeochemical Cycles ◽  
Bacterial Genes ◽  
The Impact

Viruses are the most abundant biological entities in the world’s oceans, and they play a crucial role in global biogeochemical cycles. In deep-sea ecosystems, archaea and bacteria drive major nutrient cycles, and viruses are largely responsible for their mortality, thereby exerting important controls on microbial dynamics. However, the relative impact of viruses on archaea compared to bacteria is unknown, limiting our understanding of the factors controlling the functioning of marine systems at a global scale. We evaluate the selectivity of viral infections by using several independent approaches, including an innovative molecular method based on the quantification of archaeal versus bacterial genes released by viral lysis. We provide evidence that, in all oceanic surface sediments (from 1000- to 10,000-m water depth), the impact of viral infection is higher on archaea than on bacteria. We also found that, within deep-sea benthic archaea, the impact of viruses was mainly directed at members of specific clades of Marine Group I Thaumarchaeota. Although archaea represent, on average, ~12% of the total cell abundance in the top 50 cm of sediment, virus-induced lysis of archaea accounts for up to one-third of the total microbial biomass killed, resulting in the release of ~0.3 to 0.5 gigatons of carbon per year globally. Our results indicate that viral infection represents a key mechanism controlling the turnover of archaea in surface deep-sea sediments. We conclude that interactions between archaea and their viruses might play a profound, previously underestimated role in the functioning of deep-sea ecosystems and in global biogeochemical cycles.

scholarly journals Using Community Science to Reveal the Global Chemogeography of River Metabolomes

2020 ◽  
Author(s):  
Vanessa A. Garayburu-Caruso ◽  
Robert E. Danczak ◽  
James C. Stegen ◽  
Lupita Renteria ◽  
Marcy Mccall ◽  
...  
Keyword(s):  
Surface Water ◽  
Biogeochemical Cycles ◽  
Ultrahigh Resolution ◽  
Water And Sediment ◽  
Traditional Research ◽  
Observation Network ◽  
Significant Spatial Variation ◽  
Community Science ◽  
Key Aspects ◽  
River Corridor

AbstractRiver corridor metabolomes reflect organic matter (OM) processing that drives aquatic biogeochemical cycles. Recent work highlights the power of ultrahigh-resolution mass spectrometry for understanding metabolome composition and river corridor metabolism. However, there have been no studies on the global chemogeography of surface water and sediment metabolomes using ultrahigh-resolution techniques. Here, we describe a community science effort from the Worldwide Hydrobiogeochemistry Observation Network for Dynamic River Systems (WHONDRS) consortium to characterize global metabolomes in surface water and sediment that span multiple stream orders and biomes. We describe the distribution of key aspects of metabolomes including elemental groups, chemical classes, indices, and inferred biochemical transformations. We show that metabolomes significantly differ across surface water and sediment and that surface water metabolomes are more rich and variable. We also use inferred biochemical transformations to identify core metabolic processes shared among surface water and sediment. Finally, we observe significant spatial variation in sediment metabolites between rivers in the eastern and western portions of the contiguous United States. Our work not only provides a basis for understanding global patterns in river corridor biogeochemical cycles but also demonstrates that community science endeavors can enable global research projects that are unfeasible with traditional research models.

scholarly journals Redox-informed models of global biogeochemical cycles

2019 ◽  
Author(s):  
Emily Zakem ◽  
Martin Polz ◽  
Mick Follows
Keyword(s):  
Biogeochemical Cycles ◽  
Global Biogeochemical Cycles
Sign in / Sign up

Export Citation Format

Share Document