-
Nature Communications Nov 2020The spontaneous self-assembly of multicellular ensembles into living materials with synergistic structure and function remains a considerable challenge in biotechnology...
The spontaneous self-assembly of multicellular ensembles into living materials with synergistic structure and function remains a considerable challenge in biotechnology and synthetic biology. Here, we exploit the aqueous two-phase separation of dextran-in-PEG emulsion micro-droplets for the capture, spatial organization and immobilization of algal cells or algal/bacterial cell communities to produce discrete multicellular spheroids capable of both aerobic (oxygen producing) and hypoxic (hydrogen producing) photosynthesis in daylight under air. We show that localized oxygen depletion results in hydrogen production from the core of the algal microscale reactor, and demonstrate that enhanced levels of hydrogen evolution can be achieved synergistically by spontaneously enclosing the photosynthetic cells within a shell of bacterial cells undergoing aerobic respiration. Our results highlight a promising droplet-based environmentally benign approach to dispersible photosynthetic microbial micro-reactors comprising segregated cellular micro-niches with dual functionality, and provide a step towards photobiological hydrogen production under aerobic conditions.
Topics: Aerobiosis; Bioreactors; Cell Hypoxia; Chlorella; Escherichia coli; Hydrogen; Industrial Microbiology; Microbiota; Oxygen; Photosynthesis; Renewable Energy
PubMed: 33239636
DOI: 10.1038/s41467-020-19823-5 -
Journal of Dairy Science Oct 2021We evaluated the ability of an inoculant containing a combination of Lactobacillus hilgardii and Lactobacillus buchneri to modify the microbiome and improve the aerobic...
The effects of Lactobacillus hilgardii 4785 and Lactobacillus buchneri 40788 on the microbiome, fermentation, and aerobic stability of corn silage ensiled for various times.
We evaluated the ability of an inoculant containing a combination of Lactobacillus hilgardii and Lactobacillus buchneri to modify the microbiome and improve the aerobic stability of whole-plant corn silage after various lengths of ensiling. Chopped whole-plant corn at about 33% dry matter (DM) was uninoculated (CTR) or inoculated with L. hilgardii CNCM I-4785 and L. buchneri NCIMB 40788 at 200,000 cfu/g of fresh forage weight each (combined application rate of 400,000 cfu of lactic acid bacteria/g of fresh forage weight; LHLB), L. buchneri NCIMB 40788 at 400,000 cfu/g of fresh forage weight and Pediococcus pentosaceus NCIMB 12455 at 100,000 cfu/g of fresh forage weight, used as a positive control (LB500), L. hilgardii CNCM I-4785 at the application rate used in the LHLB formulation of 200,000 cfu/g of fresh forage weight (LH), or L. buchneri NCIMB 40788 at the application rate used in the LHLB formulation of 200,000 cfu/g of fresh forage weight (LB). Silos were opened after 34 and 99 d of ensiling and analyzed for nutrient composition, fermentation profile, microbiome, and aerobic stability. After 34 d of ensiling, the inoculated silages had greater numbers of culturable lactic acid bacteria, a bacterial community less rich and diverse, greater relative abundance of Lactobacillus, lower relative abundance of Klebsiella, and a greater concentration of propionic acid than uninoculated silages. Inoculation decreased the ratio of lactic acid to acetic acid, except for LB alone. Treatment LHLB resulted in silage with a greater concentration of 1,2-propanediol than LB500 and was the only treatment to have a lower relative abundance of Saccharomycetes compared with uninoculated silage. Treatments LHLB and LB500 improved the aerobic stability compared with CTR, but the individual LH and LB treatments applied at a low dose did not. Whereas LB500 was stable 34 h longer than CTR, LHLB was stable 91 h longer. After 99 d of ensiling, all inoculated silages had markedly greater aerobic stability than uninoculated silage and were stable for more than 360 h. The inoculant containing a combination of L. hilgardii and L. buchneri markedly improved the aerobic stability of corn silage after a relatively short period of ensiling, and such improvements were greater than the ones obtained from inoculation with the combination of L. buchneri and P. pentosaceus. Inoculating with the combination of L. hilgardii and L. buchneri may be helpful to producers that must feed silage shortly after ensiling.
Topics: Aerobiosis; Animals; Fermentation; Lactobacillus; Microbiota; Silage; Zea mays
PubMed: 34334198
DOI: 10.3168/jds.2020-20111 -
Journal of Dairy Science Oct 2021There is an increasing recognition throughout the world that many of the feeding problems of dairy herds are linked to the presence of aerobically deteriorated parts on...
There is an increasing recognition throughout the world that many of the feeding problems of dairy herds are linked to the presence of aerobically deteriorated parts on a silo face, causing farmers to pose questions on what amount of silage should be removed daily to feed their animals. Since an adequate feed-out rate helps to prevent silage spoilage, a simple tool is needed to manage the aerobic deterioration of corn silages during feed-out. The aims of this study were to develop an unloading rate index, which we have called the mass feed-out rate (MFR), expressed in kilograms of fresh matter silage unloaded daily per square meter of silo face, to better predict the aerobic deterioration of silage and to offer management solutions to help prevent spoilage, through a survey on 97 commercial dairy farms in Italy and Brazil. Silages were sampled and analyzed for their main microbial, fermentative, and nutritional characteristics, whereas silage temperatures were measured in the core and peripheral areas of the silo working face. Moreover, a detailed questionnaire on silo management and silage utilization was administered to the farmers during each farm visit. The size and silage density of the silos presented a wide variability in the 2 countries, thus indicating that different management practices were adopted during corn harvesting, silo filling, and silage compaction. The differences between pH and temperature in the peripheral areas and in the core of the silage (dpH and dT, respectively) were tested as a single indicator to identify any aerobic deteriorated areas on the silo face, associated with the yeast and mold counts. Both indicators correctly identified aerobic deterioration in 86.6% and 93.8% of the studied silos, respectively. The lactic acid and ethanol increased as the MFR increased, whereas the starch, dT, and the yeast and mold counts decreased with increasing MFR. A daily removal rate of over 250 kg of silage/m markedly reduced the risk of spoilage in corn silages at a farm level in both temperate and tropical environments. The new MFR index can substitute for the commonly used linear feed-out rate as it includes the silage density and can be obtained from 1 single recording.
Topics: Aerobiosis; Animals; Fermentation; Fungi; Silage; Yeasts; Zea mays
PubMed: 34275635
DOI: 10.3168/jds.2021-20419 -
Applied Human Science : Journal of... Sep 1998Environmental and cultural aspects are known to influence particular characteristics of an ethnic group and, as such, are partially responsible for distinguishing an... (Comparative Study)
Comparative Study
Environmental and cultural aspects are known to influence particular characteristics of an ethnic group and, as such, are partially responsible for distinguishing an ethnic group from others. This study was designed to compare non-athlete young Japanese and American males on a variety of physiological and fitness characteristics in order to locate and quantify the magnitude of any physiological and fitness differences between the two races. Aerobic capacity based upon bicycle ergometer, resting heart rate, and resting blood pressure, vertical jump, grip strength, and flexibility as measured by sit-and-reach, and trunk-and-neck extension tests were obtained for 20 Japanese and 20 American males whose ages ranged between 19 and 25 years. Cardiovascular and aerobic capacity data indicated that the Americans had higher blood pressure (both systolic and diastolic blood pressures) and higher absolute VO2max than the Japanese. However, the Japanese had a higher relative VO2max value than the Americans. The Japanese had higher values than those of the Americans in the vertical jump and for trunk-and-neck flexibility. Within the limitation of the present study, it can be concluded that the Japanese had a higher lower extremity power and better flexibility in the trunk-and-neck extension compared with the American.
Topics: Adult; Aerobiosis; Asian People; Blood Pressure; Heart Rate; Humans; Japan; Male; Physical Fitness; United States; White People
PubMed: 9844247
DOI: 10.2114/jpa.17.189 -
Microbial Biotechnology Jan 2019Methionine is essential for life. Its chemistry makes it fragile in the presence of oxygen. Aerobic living organisms have selected a salvage pathway (the MSP) that uses...
Methionine is essential for life. Its chemistry makes it fragile in the presence of oxygen. Aerobic living organisms have selected a salvage pathway (the MSP) that uses dioxygen to regenerate methionine, associated to a ratchet-like step that prevents methionine back degradation. Here, we describe the variation on this theme, developed across the tree of life. Oxygen appeared long after life had developed on Earth. The canonical MSP evolved from ancestors that used both predecessors of ribulose bisphosphate carboxylase oxygenase (RuBisCO) and methanethiol in intermediate steps. We document how these likely promiscuous pathways were also used to metabolize the omnipresent by-products of S-adenosylmethionine radical enzymes as well as the aromatic and isoprene skeleton of quinone electron acceptors.
Topics: Aerobiosis; Metabolic Networks and Pathways; Methionine; Oxidation-Reduction; Oxygen; Quinones
PubMed: 30306718
DOI: 10.1111/1751-7915.13324 -
Nature Metabolism Sep 2020Increased aerobic exercise capacity, as a result of exercise training, has important health benefits. However, some individuals are resistant to improvements in exercise...
Increased aerobic exercise capacity, as a result of exercise training, has important health benefits. However, some individuals are resistant to improvements in exercise capacity, probably due to undetermined genetic and environmental factors. Here, we show that exercise-induced improvements in aerobic capacity are blunted and aerobic remodelling of skeletal muscle is impaired in several animal models associated with chronic hyperglycaemia. Our data point to chronic hyperglycaemia as a potential negative regulator of aerobic adaptation, in part, via glucose-mediated modifications of the extracellular matrix, impaired vascularization and aberrant mechanical signalling in muscle. We also observe low exercise capacity and enhanced c-Jun N-terminal kinase activation in response to exercise in humans with impaired glucose tolerance. Our work indicates that current shifts in dietary and metabolic health, associated with increasing incidence of hyperglycaemia, might impair muscular and organismal adaptations to exercise training, including aerobic capacity as one of its key health outcomes.
Topics: Adaptation, Physiological; Adult; Aerobiosis; Anaerobic Threshold; Animals; Endothelial Cells; Enzyme Activation; Exercise; Female; Glucose Intolerance; Humans; Hyperglycemia; JNK Mitogen-Activated Protein Kinases; Male; Mice; Muscle, Skeletal; Physical Conditioning, Animal; Rats; Signal Transduction; Young Adult
PubMed: 32694831
DOI: 10.1038/s42255-020-0240-7 -
International Journal of Environmental... Jul 2022Improving treatment efficiency and reducing investment and operating costs make aerobic granular sludge technology (AGS) a promising technology for treating aquaculture...
Improving treatment efficiency and reducing investment and operating costs make aerobic granular sludge technology (AGS) a promising technology for treating aquaculture wastewater. The development of continuous flow reactors (CFRs) has become a new direction in the research of AGS. This study clarifies the granulation effect, hydrodynamic behavior and particle separation of three different CFRs (R1 to R3). The established CFD model was able to explain the hydrodynamic behavior in all three CFRs; in particular, R3 performed the best from the perspective of hydrodynamic behavior due to its abundant turbulence. In addition, the optimal baffle distance and baffle angle of R3 were simulated to be 40 mm and 60°, respectively, due to them providing the best turbulent flow and particle separation effect. However, an overlarge baffle angle could weaken the turbulent pattern in the reactor. The retention time distribution further confirmed the reasonability of these optimal parameters with the highest effective volume ratio of 0.82. In short, this study gives an instruction for exploring the rapid formation mechanism of AGS in a CFR to promote its engineering application.
Topics: Aerobiosis; Bioreactors; Hydrodynamics; Sewage; Waste Disposal, Fluid
PubMed: 35886165
DOI: 10.3390/ijerph19148306 -
Aging Jan 2020A reduction in aerobic capacity and the shortening of telomeres are hallmarks of the ageing process. We examined whether a lower aerobic capacity is associated with...
A reduction in aerobic capacity and the shortening of telomeres are hallmarks of the ageing process. We examined whether a lower aerobic capacity is associated with shorter TL in skeletal muscle and/or leukocytes, across a wide age range of individuals. We also tested whether TL in human skeletal muscle (MTL) correlates with TL in leukocytes (LTL). Eighty-two recreationally active, healthy men from the Gene SMART cohort (31.4±8.2 years; body mass index (BMI)=25.3±3.3kg/m), and 11 community dwelling older men (74.2±7.5years-old; BMI=28.7±2.8kg/m) participated in the study. Leukocytes and skeletal muscle samples were collected at rest. Relative telomere length (T/S ratio) was measured by RT-PCR. Associations between TL, aerobic capacity (VO peak and peak power) and age were assessed with robust linear models. Older age was associated with shorter LTL (45% variance explained, P<0.001), but not MTL (P= 0.7). Aerobic capacity was not associated with MTL (P=0.5), nor LTL (P=0.3). MTL and LTL were correlated across the lifespan (r=0.26, P=0.03). In healthy individuals, age explain most of the variability of LTL and this appears to be independent of individual aerobic capacity. Individuals with longer LTL also have a longer MTL, suggesting that there might be a shared molecular mechanism regulating telomere length.
Topics: Adult; Aerobiosis; Aging; Female; Humans; Leukocytes; Longevity; Male; Muscle, Skeletal; Physical Fitness; Telomere; Telomere Homeostasis
PubMed: 31901896
DOI: 10.18632/aging.102627 -
PloS One 2011As tumors outgrow their blood supply and become oxygen deprived, they switch to less energetically efficient but oxygen-independent anaerobic glucose metabolism....
As tumors outgrow their blood supply and become oxygen deprived, they switch to less energetically efficient but oxygen-independent anaerobic glucose metabolism. However, cancer cells maintain glycolytic phenotype even in the areas of ample oxygen supply (Warburg effect). It has been hypothesized that the competitive advantage that glycolytic cells get over aerobic cells is achieved through secretion of lactic acid, which is a by-product of glycolysis. It creates acidic microenvironment around the tumor that can be toxic to normal somatic cells. This interaction can be seen as a prisoner's dilemma: from the point of view of metabolic payoffs, it is better for cells to cooperate and become better competitors but neither cell has an incentive to unilaterally change its metabolic strategy. In this paper a novel mathematical technique, which allows reducing an otherwise infinitely dimensional system to low dimensionality, is used to demonstrate that changing the environment can take the cells out of this equilibrium and that it is cooperation that can in fact lead to the cell population committing evolutionary suicide.
Topics: Aerobiosis; Cell Proliferation; Clone Cells; Game Theory; Glycolysis; Humans; Models, Biological; Neoplasms; Oxygen; Tumor Microenvironment
PubMed: 22194857
DOI: 10.1371/journal.pone.0028576 -
Biochimica Et Biophysica Acta Dec 2008Respiration is fundamental to the aerobic and anaerobic energy metabolism of many prokaryotic and most eukaryotic organisms. In principle, the free energy of a redox... (Review)
Review
Respiration is fundamental to the aerobic and anaerobic energy metabolism of many prokaryotic and most eukaryotic organisms. In principle, the free energy of a redox reaction catalysed by a membrane-bound electron transport chain is transduced via the generation of an electrochemical ion (usually proton) gradient across a coupling membrane that drives ATP synthesis. The proton motive force (pmf) can be built up by different mechanisms like proton pumping, quinone/quinol cycling or by a redox loop. The latter couples electron transport to a net proton transfer across the membrane without proton pumping. Instead, charge separation is achieved by quinone-reactive enzymes or enzyme complexes whose active sites for substrates and quinones are situated on different sides of the coupling membrane. The necessary transmembrane electron transport is usually accomplished by the presence of two haem groups that face opposite sides of the membrane. There are many different enzyme complexes that are part of redox loops and their catalysed redox reactions can be either electrogenic, electroneutral (non-proton motive) or even pmf-consuming. This article gives conceptual classification of different operational organisations of redox loops and uses this as a platform from which to explore the biodiversity of quinone/quinol-cycling redox systems.
Topics: Aerobiosis; Hydroquinones; Oxidation-Reduction; Prokaryotic Cells; Proton-Motive Force; Quinones
PubMed: 18930017
DOI: 10.1016/j.bbabio.2008.09.008