scholarly journals Oxygen consumption of individual cable bacteria

2021 ◽  
Vol 7 (7) ◽  
pp. eabe1870
Author(s):  
Stefano Scilipoti ◽  
Klaus Koren ◽  
Nils Risgaard-Petersen ◽  
Andreas Schramm ◽  
Lars Peter Nielsen
Keyword(s):  
Oxidative Stress ◽  
Oxygen Consumption ◽  
Energy Conservation ◽  
Electron Donor ◽  
Aerobic Respiration ◽  
Aquatic Sediments ◽  
Consumption Rates ◽  
Electrical Signaling

The electric wires of cable bacteria possibly support a unique respiration mode with a few oxygen-reducing cells flaring off electrons, while oxidation of the electron donor and the associated energy conservation and growth is allocated to other cells not exposed to oxygen. Cable bacteria are centimeter-long, multicellular, filamentous Desulfobulbaceae that transport electrons across oxic-anoxic interfaces in aquatic sediments. From observed distortions of the oxic-anoxic interface, we derived oxygen consumption rates of individual cable bacteria and found biomass-specific rates of unheard magnitude in biology. Tightly controlled behavior, possibly involving intercellular electrical signaling, was found to generally keep <10% of individual filaments exposed to oxygen. The results strengthen the hypothesis that cable bacteria indeed have evolved an exceptional way to take the full energetic advantages of aerobic respiration and let >90% of the cells metabolize in the convenient absence of oxidative stress.

scholarly journals Responses of hypertrophied myocytes to reactive species: implications for glycolysis and electrophile metabolism

2011 ◽  
Vol 435 (2) ◽  
pp. 519-528 ◽  
Author(s):  
Brian E. Sansbury ◽  
Daniel W. Riggs ◽  
Robert E. Brainard ◽  
Joshua K. Salabei ◽  
Steven P. Jones ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Oxygen Consumption ◽  
Energy Demand ◽  
Lactate Production ◽  
Fold Increase ◽  
Cellular Protein ◽  
Reactive Species ◽  
Neonatal Rat ◽  
Glycolytic Flux ◽  
Rat Cardiomyocytes

During cardiac remodelling, the heart generates higher levels of reactive species; yet an intermediate ‘compensatory’ stage of hypertrophy is associated with a greater ability to withstand oxidative stress. The mechanisms underlying this protected myocardial phenotype are poorly understood. We examined how a cellular model of hypertrophy deals with electrophilic insults, such as would occur upon ischaemia or in the failing heart. For this, we measured energetics in control and PE (phenylephrine)-treated NRCMs (neonatal rat cardiomyocytes) under basal conditions and when stressed with HNE (4-hydroxynonenal). PE treatment caused hypertrophy as indicated by augmented atrial natriuretic peptide and increased cellular protein content. Hypertrophied myocytes demonstrated a 2.5-fold increase in ATP-linked oxygen consumption and a robust augmentation of oligomycin-stimulated glycolytic flux and lactate production. Hypertrophied myocytes displayed a protected phenotype that was resistant to HNE-induced cell death and a unique bioenergetic response characterized by a delayed and abrogated rate of oxygen consumption and a 2-fold increase in glycolysis upon HNE exposure. This augmentation of glycolytic flux was not due to increased glucose uptake, suggesting that electrophile stress results in utilization of intracellular glycogen stores to support the increased energy demand. Hypertrophied myocytes also had an increased propensity to oxidize HNE to 4-hydroxynonenoic acid and sustained less protein damage due to acute HNE insults. Inhibition of aldehyde dehydrogenase resulted in bioenergetic collapse when myocytes were challenged with HNE. The integration of electrophile metabolism with glycolytic and mitochondrial energy production appears to be important for maintaining myocyte homoeostasis under conditions of increased oxidative stress.

scholarly journals Oxygen consumption rates in subseafloor basaltic crust derived from a reaction transport model

2013 ◽  
Vol 4 (1) ◽  
Author(s):  
Beth N. Orcutt ◽  
C. Geoffrey Wheat ◽  
Olivier Rouxel ◽  
Samuel Hulme ◽  
Katrina J. Edwards ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Transport Model ◽  
Consumption Rates ◽  
Reaction Transport ◽  
Basaltic Crust

The Relation of Oxygen Consumption to Body Size and to Temperature in the Larvae of Chironomus Riparius Meigen

1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Dry Matter ◽  
Larval Instar ◽  
Weight Ratio ◽  
Dry Weight ◽  
Chironomus Riparius ◽  
Consumption Rates ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.

scholarly journals Mitochondrial Fragmentation in Skeletal Muscle Derived Cells from an Old Male Donor May Relate to Decreased Oxygen Consumption Rates

2020 ◽  
Vol 34 (S1) ◽  
pp. 1-1
Author(s):  
José Adan Arevalo ◽  
Marvin L. Miller ◽  
José Pablo Vazquez-Medina ◽  
George A. Brooks
Keyword(s):  
Skeletal Muscle ◽  
Oxygen Consumption ◽  
Mitochondrial Fragmentation ◽  
Male Donor ◽  
Consumption Rates

scholarly journals Direct measurement of oxygen consumption rates from attached and unattached cells in a reversibly sealed, diffusionally isolated sample chamber

2010 ◽  
Vol 01 (05) ◽  
pp. 398-408 ◽  
Author(s):  
Timothy J. Strovas ◽  
Sarah C. McQuaide ◽  
Judy B. Anderson ◽  
Vivek Nandakumar ◽  
Marina G. Kalyuzhnaya ◽  
...  
Keyword(s):  
Oxygen Consumption ◽  
Direct Measurement ◽  
Consumption Rates ◽  
Sample Chamber

A comparison of the gill physiology of two euryhaline crab species, Callinectes sapidus and Callinectes similis: energy production, transport-related enzymes and osmoregulation as a function of acclimation salinity

1995 ◽  
Vol 198 (2) ◽  
pp. 349-358 ◽  
Author(s):  
S Piller ◽  
R Henry ◽  
J Doeller ◽  
D Kraus
Keyword(s):  
Oxygen Consumption ◽  
Energy Production ◽  
Consumption Rate ◽  
Callinectes Sapidus ◽  
Crab Species ◽  
Ion Concentrations ◽  
Low Salinity ◽  
Consumption Rates ◽  
Cytochrome Content ◽  
Mitochondrial Cytochromes

Callinectes sapidus and C. similis co-occur in estuarine waters above 15 salinity. Callinectes sapidus also inhabits more dilute waters, but C. similis is rarely found below 15 . Previous work suggests that C. sapidus may be a better hyperosmoregulator than C. similis. In this study, energy metabolism and the levels of transport-related enzymes in excised gills were used as indicators of adaptation to low salinity. Oxygen consumption rates and mitochondrial cytochrome content of excised gills increased in both species as acclimation salinity decreased, but to a significantly greater extent in C. similis gills. In addition, C. similis gills showed the same levels of carbonic anhydrase and Na+/K+-ATPase activities and the same degree of enzyme induction during low-salinity adaptation as has been reported for C. sapidus gills. However, hemolymph osmolality and ion concentrations were consistently lower in C. similis at low salinity than in C. sapidus. Therefore, although gills from low-salinity-acclimated C. similis have a higher oxygen consumption rate and more mitochondrial cytochromes than C. sapidus gills and the same level of transport-related enzymes, C. similis cannot homeostatically regulate their hemolymph to the same extent as C. sapidus.

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