Growth of Cyanobacterium aponinum influenced by increasing salt concentrations and temperature.
Ontology highlight
ABSTRACT:
SUBMITTER: Winckelmann D
PROVIDER: S-EPMC4434411 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Common indoor and outdoor environmental fungi such as Aspergillus fumigatus produce asexual spores containing a collection of proteins that can bind IgE antibodies and trigger allergic reactions. We characterized the impact of sporulation temperature on the IgE-binding capacity (allergenicity) of A. fumigatus and explored the links between variable allergenicity and temperature-dependant expression of genes encoding these allergenic proteins. A 12-fold increase in A. fumigatus allergenicity per spore was observed when sporulation temperatures were decreased from 32°C to 17°C. Per spore protein mass and Asp f 1 allergen mass also followed this trend. Functional gene expression analysis of A. fumigatus sporulating cultures by real-time reverse-transcription PCR and gene expression microarrays revealed that a greater number of genes encoding known, major allergens are more highly expressed at lower sporulation temperatures. The results of this study indicate that environmental conditions at growth significantly influence the allergenicity of this common mould through the differential production of allergenic proteins, and highlight the importance of in vivo or in vitro allergenicity measurements for understanding environmental exposure to airborne allergenic fungi.
| S-EPMC3822576 | biostudies-literature
Project description:Genetic diversity and temperature increases associated with global climate change are known to independently influence population growth and extinction risk. Whether increasing temperature may influence the effect of genetic diversity on population growth, however, is not known. We address this issue in the model protist system Tetrahymena thermophila. We test the hypothesis that at temperatures closer to the species' thermal optimum (i.e., the temperature at which population growth is maximal, or T opt), genetic diversity should have a weaker effect on population growth compared to temperatures away from the thermal optimum. To do so, we grew populations of T. thermophila with varying levels of genetic diversity at increasingly warmer temperatures and quantified their intrinsic population growth rate, r. We found that genetic diversity increases population growth at cooler temperatures, but that as temperature increases, this effect weakens. We also show that a combination of changes in the amount of expressed genetic diversity (G) in r, plastic changes in population growth across temperatures (E), and strong G × E interactions underlie this temperature effect. Our results uncover important but largely overlooked temperature effects that have implications for the management of small populations with depauperate genetic stocks in an increasingly warming world.
| S-EPMC8717318 | biostudies-literature
Project description:Increasing atmospheric CO₂ concentrations are expected to impact pelagic ecosystem functioning in the near future by driving ocean warming and acidification. While numerous studies have investigated impacts of rising temperature and seawater acidification on planktonic organisms separately, little is presently known on their combined effects. To test for possible synergistic effects we exposed two coccolithophore species, Emiliania huxleyi and Gephyrocapsa oceanica, to a CO₂ gradient ranging from ∼0.5-250 µmol kg⁻¹ (i.e. ∼20-6000 µatm pCO₂) at three different temperatures (i.e. 10, 15, 20°C for E. huxleyi and 15, 20, 25°C for G. oceanica). Both species showed CO₂-dependent optimum-curve responses for growth, photosynthesis and calcification rates at all temperatures. Increased temperature generally enhanced growth and production rates and modified sensitivities of metabolic processes to increasing CO₂. CO₂ optimum concentrations for growth, calcification, and organic carbon fixation rates were only marginally influenced from low to intermediate temperatures. However, there was a clear optimum shift towards higher CO₂ concentrations from intermediate to high temperatures in both species. Our results demonstrate that the CO₂ concentration where optimum growth, calcification and carbon fixation rates occur is modulated by temperature. Thus, the response of a coccolithophore strain to ocean acidification at a given temperature can be negative, neutral or positive depending on that strain's temperature optimum. This emphasizes that the cellular responses of coccolithophores to ocean acidification can only be judged accurately when interpreted in the proper eco-physiological context of a given strain or species. Addressing the synergistic effects of changing carbonate chemistry and temperature is an essential step when assessing the success of coccolithophores in the future ocean.
| S-EPMC3914986 | biostudies-literature
Project description:We show here that fundamental aspects of antitumor immunity in mice are significantly influenced by ambient housing temperature. Standard housing temperature for laboratory mice in research facilities is mandated to be between 20-26 °C; however, these subthermoneutral temperatures cause mild chronic cold stress, activating thermogenesis to maintain normal body temperature. When stress is alleviated by housing at thermoneutral ambient temperature (30-31 °C), we observe a striking reduction in tumor formation, growth rate and metastasis. This improved control of tumor growth is dependent upon the adaptive immune system. We observe significantly increased numbers of antigen-specific CD8(+) T lymphocytes and CD8(+) T cells with an activated phenotype in the tumor microenvironment at thermoneutrality. At the same time there is a significant reduction in numbers of immunosuppressive MDSCs and regulatory T lymphocytes. Notably, in temperature preference studies, tumor-bearing mice select a higher ambient temperature than non-tumor-bearing mice, suggesting that tumor-bearing mice experience a greater degree of cold-stress. Overall, our data raise the hypothesis that suppression of antitumor immunity is an outcome of cold stress-induced thermogenesis. Therefore, the common approach of studying immunity against tumors in mice housed only at standard room temperature may be limiting our understanding of the full potential of the antitumor immune response.
| S-EPMC3864348 | biostudies-literature
Project description:The kinetic energy of a force-free granular gas decays monotonously due to inelastic collisions of the particles. For a homogeneous granular gas of identical particles, the corresponding decay of granular temperature is quantified by Haff's law. Here, we report that for a granular gas of aggregating particles, the granular temperature does not necessarily decay but may even increase. Surprisingly, the increase of temperature is accompanied by the continuous loss of total gas energy. This stunning effect arises from a subtle interplay between decaying kinetic energy and gradual reduction of the number of degrees of freedom associated with the particles' dynamics. We derive a set of kinetic equations of Smoluchowski type for the concentrations of aggregates of different sizes and their energies. We find scaling solutions to these equations and a condition for the aggregation mechanism predicting growth of temperature. Numerical direct simulation Monte Carlo results confirm the theoretical predictions.
| S-EPMC5824832 | biostudies-other
Project description:A new estuarine filamentous heterocystous cyanobacterium was isolated from intertidal sediment of the Lagoa dos Patos estuary (Brazil). The isolate may represent a new genus related to Cylindrospermopsis. While the latter is planktonic, contains gas vesicles, and is toxic, the newly isolated strain is benthic and does not contain gas vesicles. It is not known whether the new strain is toxic. It grows equally well in freshwater, brackish and full salinity growth media, in the absence of inorganic or organic combined nitrogen, with a growth rate 0.6 d-1. Nitrogenase, the enzyme complex responsible for fixing dinitrogen, was most active during the initial growth phase and its activity was not different between the different salinities tested (freshwater, brackish, and full salinity seawater). Salinity shock also did not affect nitrogenase activity. The frequency of heterocysts was high, coinciding with high nitrogenase activity during the initial growth phase, but decreased subsequently. However, the frequency of heterocysts decreased considerably more at higher salinity, while no change in nitrogenase activity occurred, indicating a higher efficiency of dinitrogen fixation. Akinete frequency was low in the initial growth phase and higher in the late growth phase. Akinete frequency was much lower at high salinity, which might indicate better growth conditions or that akinete differentiation was under the same control as heterocyst differentiation. These trends have hitherto not been reported for heterocystous cyanobacteria but they seem to be well fitted for an estuarine life style.
| S-EPMC5472669 | biostudies-literature
Project description:Rocket salad species (Diplotaxis tenuifolia and Eruca sativa; also known as E. vesicaria) are known for their high concentrations of health-related isothiocyanates, which are derived from secondary metabolites called glucosinolates. Increases in temperature due to climate change and extreme weather event frequencies over the coming decades are likely to influence not only the growth of leafy vegetables, but also their nutritional density. It is therefore essential to determine the impacts of these in order to mitigate crop losses and nutritional decline in future. Our data show there is a strong influence of pre-harvest growth temperatures on glucosinolate biosynthesis and formation of glucosinolate hydrolysis products postharvest, and that this is genotype dependent. High growth temperature (40 °C) severely retarded germination, growth, regrowth, and survival of rocket plants. Highest glucosinolate concentrations were observed in first and second cuts at 40 °C, but did not correspond to highest isothiocyanate concentrations (observed at 30 °C, second cut). Hydrolysis product formation is proportionately not as great as glucosinolate increases at 40 °C, possibly due to inhibition of enzyme function(s) at higher temperatures. These data indicate that high growth temperatures increase glucosinolate accumulation, but growth and productivity is significantly reduced. Much greater emphasis is needed for breeding cultivars tolerant to high growth temperatures in order to maximise nutritional benefits imparted by temperature stress.
| S-EPMC7104888 | biostudies-literature
Project description:Vitamin and mineral deficiencies are prevalent in human populations throughout the world. Vitamin A deficiency affects hundreds of millions of pre-school age children in low income countries. Fruits of pepper (Capsicum annuum L.) can be a major dietary source of precursors to Vitamin A biosynthesis, such as ?-carotene. Recently, pepper breeding programs have introduced the orange-fruited (of) trait of the mutant variety Oranzheva kapiya, which is associated with high fruit ?-carotene concentrations, to the mutant variety Albena. In this manuscript, concentrations of ?-carotene and mineral elements (magnesium, phosphorus, sulphur, potassium, zinc, calcium, manganese, iron and copper) were compared in fruit from P31, a red-fruited genotype derived from the variety Albena, and M38, a genotype developed by transferring the orange-fruited mutation (of) into Albena. It was observed that fruit from M38 plants had greater ?-carotene concentration at both commercial and botanical maturity (4.9 and 52.7 mg / kg fresh weight, respectively) than fruit from P31 plants (2.3 and 30.1 mg / kg fresh weight, respectively). The mutation producing high ?-carotene concentrations in pepper fruits had no detrimental effect on the concentrations of mineral elements required for human nutrition.
| S-EPMC5313226 | biostudies-literature
Project description:Breast milk contains bile salt-stimulated lipase (BSSL), which significantly increases the fat digestion capacity of newborns who have limited pancreatic lipase secretion in the first few months after birth. Problematically, Holder pasteurization used in non-profit milk banks to ensure the microbiological safety of donor milk for infants, particularly preterm infants (<37 weeks gestation age), destroys milk BSSL, thus limiting infant fat absorption capacity. Alternative strategies are needed to ensure the safety of donor milk while preserving BSSL activity. Three alternative pasteurization techniques-high-pressure processing (HPP, 550 MPa, 5 min), gamma cell irradiation (IR, 2.5 Mrads) and UV-C (254 nm, 0-33,000 J/L)-were compared with Holder pasteurization (low-temperature long-time, LTLT, 62.5°C, 30 min) for retention of BSSL activity in donor breast milk. As the time required for donor milk pasteurization by UV-C in published methods was not clear, donor breast milk was spiked with seven common bacterial strains and treated by UV-C for variable time periods and the minimum UV-C dosage required to achieve a 5-log10 reduction of CFU/mL was determined. Eight thousand two hundred fifty J/L of UV-C exposure was sufficient to achieve 5-log10 reduction of each of bacterial targets, including Bacillus and Paenibacillus spores. The retention of BSSL activity was highest after HPP (retaining 62% of the untreated milk BSSL activity), followed by UV-C (16,500 J/L), IR and LTLT (35, 29, and 0.3% retention, respectively). HPP was an effective alternative to pasteurize milk with improved retention of BSSL activity compared to Holder pasteurization. Future work should investigate the effect of alternative pasteurization techniques on the entire array of bioactive components in donor breast milk and how these changes affect preterm infant health outcomes. Implementation of HPP technique at milk banks could improve donor milk-fed infant fat absorption and growth.
| S-EPMC7689290 | biostudies-literature
Project description:The cell membrane forms a dynamic and complex barrier between the living cell and its environment. However, its in vivo studies are difficult because it consists of a high variety of lipids and proteins and is continuously reorganized by the cell. Therefore, membrane model systems with precisely controlled composition are used to investigate fundamental interactions of membrane components under well-defined conditions. Giant unilamellar vesicles (GUVs) offer a powerful model system for the cell membrane, but many previous studies have been performed in unphysiologically low ionic strength solutions which might lead to altered membrane properties, protein stability and lipid-protein interaction. In the present work, we give an overview of the existing methods for GUV production and present our efforts on forming single, free floating vesicles up to several tens of ?m in diameter and at high yield in various buffer solutions with physiological ionic strength and pH.
| S-EPMC5303729 | biostudies-literature