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Water Science and Technology : a... Nov 2021Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of... (Review)
Review
Currently, research trends on aerobic granular sludge (AGS) have integrated the operating conditions of extracellular polymeric substances (EPS) towards the stability of AGS systems in various types of wastewater with different physical and biochemical characteristics. More attention is given to the stability of the AGS system for real site applications. Although recent studies have reported comprehensively the mechanism of AGS formation and stability in relation to other intermolecular interactions such as microbial distribution, shock loading and toxicity, standard operating condition control strategies for different types of wastewater have not yet been discussed. Thus, the dimensional multi-layer structural model of AGS is discussed comprehensively in the first part of this review paper, focusing on diameter size, thickness variability of each layer and diffusion factor. This can assist in facilitating the interrelation between disposition and stability of AGS structure to correspond to the changes in wastewater types, which is the main objective and novelty of this review.
Topics: Aerobiosis; Bioreactors; Sewage; Waste Disposal, Fluid; Wastewater
PubMed: 34810301
DOI: 10.2166/wst.2021.415 -
Der Anaesthesist Sep 2007Homeothermy is the result of an evolutionary process during which every increase in oxygen supply led to a consecutive increase in metabolic rate and, thus, to a new... (Review)
Review
Homeothermy is the result of an evolutionary process during which every increase in oxygen supply led to a consecutive increase in metabolic rate and, thus, to a new dependence on favorable ambient conditions. In response to the food scarcity of winter months, some inhabitants of temperate zones developed an ability to hibernate which is characterized by a fully thermocontrolled reduction in body temperature down to near zero values. Hibernation thus illustrates that in homeotherms, not only the body shell is poikilothermic, but also the core temperature is more variable than often assumed. However, in contrast to clinical hypothermia, natural torpidity does not consist of a cold-induced reduction in metabolic rate, but of an endogenous metabolic reduction with subsequent lowering of body temperature. As a factor of metabolic suppression, the pH has been suspected which, in hibernators, is kept constant at 7.4 by relative hypoventilation (pH-stat) which differs from its passive shift in the poikilothermic body shell (alpha-stat). In clinical hypothermia, temperature governs the metabolic rate in that, depending on the state of thermoregulation, either a cold defense reaction with an increased metabolic rate (accidental hypothermia) or a cold-induced reduction in metabolic rate (induced hypothermia) occurs. However, as can be learned from hibernators, the lower limit of hypothermia tolerance seems to be due to a uniform minimal metabolic rate rather than to the species-specific body temperature at which this metabolic limit is reached, depending on body size and basal metabolic rate. Accordingly, in judging the sequelae of hypothermia, the degree of cooling should be given less emphasis than the resulting effects on metabolic rate.
Topics: Aerobiosis; Animals; Biological Evolution; Body Temperature; Body Temperature Regulation; Hibernation; Humans; Metabolism; Phylogeny; Reference Standards
PubMed: 17763837
DOI: 10.1007/s00101-007-1220-y -
Water Science and Technology : a... 2007In September 2006, preliminary to the IWA biofilm conference, a second workshop about aerobic granular sludge was held in Delft, The Netherlands, of which a summary of... (Review)
Review
In September 2006, preliminary to the IWA biofilm conference, a second workshop about aerobic granular sludge was held in Delft, The Netherlands, of which a summary of the discussion outcomes is given in this paper. The definition of aerobic granular sludge was discussed and complemented with a few additional demands. Further topics were formation and morphology of aerobic granular sludge, modelling and use of the aerobic granular sludge in practice.
Topics: Aerobiosis; Sewage; Waste Disposal, Fluid
PubMed: 17546972
DOI: 10.2166/wst.2007.244 -
Journal of Bioenergetics and... Feb 2004Thermophiles are organisms that grow optimally above 50 degrees C and up to approximately 120 degrees C. These extreme conditions must have led to specific... (Review)
Review
Thermophiles are organisms that grow optimally above 50 degrees C and up to approximately 120 degrees C. These extreme conditions must have led to specific characteristics of the cellular components. In this paper we extensively analyze the types of respiratory complexes from thermophilic aerobic prokaryotes. The different membrane-bound complexes so far characterized are described, and the genomic data available for thermophilic archaea and bacteria are analyzed. It is observed that no specific characteristics can be associated to thermophilicity as the different types of complexes I-IV are present randomly in thermophilic aerobic organisms, as well as in mesophiles. Rather, the extensive genomic analyses indicate that the differences concerning the several complexes are related to the organism phylogeny, i.e., to evolution and lateral gene transfer events.
Topics: Aerobiosis; Archaea; Bacteria, Aerobic; Cell Membrane; Electron Transport; Oxidoreductases; Signal Transduction
PubMed: 15168613
DOI: 10.1023/b:jobb.0000019601.74394.67 -
Medicine and Science in Sports and... May 2021
Topics: Aerobiosis; Anaerobic Threshold; Animals; Exercise; Glycogen; Glycolysis; Humans; Lactic Acid; Muscle, Skeletal
PubMed: 33844671
DOI: 10.1249/MSS.0000000000002549 -
Revue Des Maladies Respiratoires Jun 2014According to a widely accepted model, based on the theory of the anaerobic threshold (AT), the increase in plasma lactate concentration which develops after the first... (Review)
Review
According to a widely accepted model, based on the theory of the anaerobic threshold (AT), the increase in plasma lactate concentration which develops after the first ventilatory threshold (VT1, considered as an AT) is due to compensation for insufficient aerobic metabolism by anaerobic glycolysis, with accumulation of lactic acid resulting in a decrease in pH. Bicarbonate is the main buffer of protons (>90%) producing non-metabolic CO2 in muscle and thus increasing the CO2 flux to the lungs. This phenomenon, along with the low pH, triggers hyperventilation. Because of this model, great importance has been placed on plasma lactate and pH. We argue that this importance is excessive and these variables should be used with caution in the interpretation of clinical exercise testing, because the model based on AT is not valid: there is no aerobic failure above VT1 and, thus, there is no evidence of an AT; the increase in plasma lactate does not reflect anaerobiosis but is the marker of the increase in the error signal needed for the stimulation of mitochondrial respiration; bicarbonate is not the main buffer during exercise (these are proteins and phosphocreatine breakdown in the muscle; hemoglobin in the blood); non-metabolic CO2 is not produced in the muscle but in the lung because of the low pH and hyperventilation (the control of which remains unknown); and the flux of CO2 to the lung does not increase at faster rate after than before VT1.
Topics: Aerobiosis; Anaerobic Threshold; Blood Chemical Analysis; Exercise; Exercise Test; Humans; Hydrogen-Ion Concentration; Hyperventilation; Lactic Acid; Models, Theoretical; Physical Exertion
PubMed: 25012038
DOI: 10.1016/j.rmr.2014.04.002 -
The Science of the Total Environment Jan 2021Plug flow reactors (PFRs) made of multiple completely stirred tank reactors (CSTRs) in series were used to cultivate aerobic granules in real domestic wastewater....
Plug flow reactors (PFRs) made of multiple completely stirred tank reactors (CSTRs) in series were used to cultivate aerobic granules in real domestic wastewater. Theoretically, changing the number of CSTR chambers in series will change the nature of plug flow, and thus alter the pattern of the feast/famine condition and impact the aerobic granulation progress. Therefore, PFRs were operated in 4-, 6-, and 8-chamber mode under the same gravity selection pressure (a critical settling velocity of 9.75 m h) and hydraulic retention time (6.5 h) until steady states were reached to evaluate the effect of the feast/famine condition on continuous flow aerobic granulation. The sludge particle size, circularity, settleability, specific gravity, zone settling velocity, and extracellular polymeric substance contents were analyzed to evaluate the role that a feast/famine regime plays in aerobic granulation. It was found that aerobic granulation failed whenever the feast/famine ratio was greater than 0.5. The results support a conclusion that the feast/famine condition is likely a prerequisite for continuous flow aerobic granulation.
Topics: Aerobiosis; Bioreactors; Extracellular Polymeric Substance Matrix; Sewage; Waste Disposal, Fluid
PubMed: 32853933
DOI: 10.1016/j.scitotenv.2020.141467 -
Giornale Italiano Della Tubercolosi 1953
Topics: Aerobiosis; Anaerobiosis; Cardiovascular System; Electrocardiography; Exercise; Heart Function Tests; Muscles
PubMed: 13128408
DOI: No ID Found -
Acta Physiologica Scandinavica Apr 2000Under aerobic work, the oxygen consumption and major ATP production occur in the mitochondria and it is therefore a relevant question whether the in vivo rates can be... (Review)
Review
Under aerobic work, the oxygen consumption and major ATP production occur in the mitochondria and it is therefore a relevant question whether the in vivo rates can be accounted for by mitochondrial capacities measured in vitro. Mitochondria were isolated from human quadriceps muscle biopsies in yields of approximately 45%. The tissue content of total creatine, mitochondrial protein and different cytochromes was estimated. A number of activities were measured in functional assays of the mitochondria: pyruvate, ketoglutarate, glutamate and succinate dehydrogenases, palmitoyl-carnitine respiration, cytochrome oxidase, the respiratory chain and the ATP synthesis. The activities involved in carbohydrate oxidation could account for in vivo oxygen uptakes of 15-16 mmol O2 min-1 kg-1 or slightly above the value measured at maximal work rates in the knee-extensor model of Saltin and co-workers, i.e. without limitation from the cardiac output. This probably indicates that the maximal oxygen consumption of the muscle is limited by the mitochondrial capacities. The in vitro activities of fatty acid oxidation corresponded to only 39% of those of carbohydrate oxidation. The maximal rate of free energy production from aerobic metabolism of glycogen was calculated from the mitochondrial activities and estimates of the DeltaG or ATP hydrolysis and the efficiency of the actin-myosin reaction. The resultant value was 20 W kg-1 or approximately 70% of the maximal in vivo work rates of which 10-20% probably are sustained by the anaerobic ATP production. The lack of aerobic in vitro ATP synthesis might reflect termination of some critical interplay between cytoplasm and mitochondria.
Topics: Aerobiosis; Humans; Mitochondria, Muscle; Muscle, Skeletal; Oxygen Consumption
PubMed: 10759584
DOI: 10.1046/j.1365-201x.2000.00699.x -
Archiv Fur Mikrobiologie 1959
Topics: Aerobiosis; Gram-Negative Bacteria; Hemeproteins; Pigments, Biological; Rhodopseudomonas; Rhodospirillum
PubMed: 13810591
DOI: 10.1007/BF00409800