Search results for "MAS"
showing 10 items of 18047 documents
Arbuscular mycorrhizal symbiosis mitigates the negative effects of salinity on durum wheat
2017
Arbuscular mycorrhizal (AM) symbiosis is generally considered to be effective in ameliorating the plant tolerance to salt stress. Unfortunately, the comprehension of the mechanisms implicated in salinity stress alleviation by AM symbiosis is far from being complete. Thus, an experiment was performed by growing durum wheat (Triticum durum Desf.) plants under salt-stress conditions to evaluate the influence of AM symbiosis on both the plant growth and the regulation of a number of genes related to salt stress and nutrient uptake. Durum wheat plants were grown outdoors in pots in absence or in presence of salt stress and with or without AM fungi inoculation. The inoculum consisted of a mixture…
Experimental approaches for testing if tolerance curves are useful for predicting fitness in fluctuating environments
2017
Most experimental studies on adaptation to stressful environments are performed under conditions that are rather constant and rarely ecologically relevant. Fluctuations in natural environmental conditions are ubiquitous and include for example variation in intensity and duration of temperature, droughts, parasite loads, and availability of nutrients, predators and competitors. The frequency and amplitude of many of these fluctuations are expected to increase with climate change. Tolerance curves are often used to describe fitness components across environmental gradients. Such curves can be obtained by assessing performance in a range of constant environmental conditions. In this perspectiv…
Oxygen Availability during Growth Modulates the Phytochemical Profile and the Chemo-Protective Properties of Spinach Juice.
2018
Fruits and vegetables are a good source of potentially biologically active compounds. Their regular consumption in the human diet can help reduce the risk of developing chronic diseases such as cardiovascular diseases and cancer. Plants produce additional chemical substances when subject to abiotic stress or infected by microorganisms. The phytochemical profile of spinach leaves (Spinacia oleracea L.), which is a vegetable with widely recognized health-promoting activity, has been affected by applying root hypoxic and re-oxygenation stress during plant growth. Leaf juice at different sampling times has been subject to liquid chromatography mass spectrometry (LC-MSn) analysis and tested on t…
Energy intake functions and energy budgets of ectotherms and endotherms derived from their ontogenetic growth in body mass and timing of sexual matur…
2017
Abstract Ectothermic and endothermic vertebrates differ not only in their source of body temperature (environment vs. metabolism), but also in growth patterns, in timing of sexual maturation within life, and energy intake functions. Here, we present a mathematical model applicable to ectothermic and endothermic vertebrates. It is designed to test whether differences in the timing of sexual maturation within an animal's life (age at which sexual maturity is reached vs. longevity) together with its ontogenetic gain in body mass (growth curve) can predict the energy intake throughout the animal's life (food intake curve) and can explain differences in energy partitioning (between growth, repro…
Modelling nonlinear dynamics of Crassulacean acid metabolism productivity and water use for global predictions
2021
Crassulacean acid metabolism (CAM) crops are important agricultural commodities in water-limited environments across the globe, yet modeling of CAM productivity lacks the sophistication of widely used C3 and C4 crop models, in part due to the complex responses of the CAM cycle to environmental conditions. This work builds on recent advances in CAM modeling to provide a framework for estimating CAM biomass yield and water use efficiency from basic principles. These advances, which integrate the CAM circadian rhythm with established models of carbon fixation, stomatal conductance, and the soil-plant-atmosphere continuum, are coupled to models of light attenuation, plant respiration, and bioma…
Marine Cryptophytes Are Great Sources of EPA and DHA
2017
Microalgae have the ability to synthetize many compounds, some of which have been recognized as a source of functional ingredients for nutraceuticals with positive health effects. One well-known example is the long-chain polyunsaturated fatty acids (PUFAs), which are essential for human nutrition. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the two most important long-chain omega-3 (-3) PUFAs involved in human physiology, and both industries are almost exclusively based on microalgae. In addition, algae produce phytosterols that reduce serum cholesterol. Here we determined the growth rates, biomass yields, PUFA and sterol content, and daily gain of eight strains of marine…
Extraction of lipids from wet microalga Auxenochlorella protothecoides using pulsed electric field treatment and ethanol-hexane blends
2017
Abstract Pulsed Electric Field (PEF) treatment was used as pre-treatment on the microalgae strain Auxenochlorella protothecoides (A.p.) prior to organic solvent extraction of lipids. Experiments were performed on fresh biomass from mixotrophic or autotrophic culture which both had an evaluated lipid content of 30–35% of cell dry weight. Lipid yield was determined gravimetrically and compared to the reference lipid content assessed by bead-milling and subsequent Soxhlet extraction. The biomass was concentrated at 10% w/w solids prior to PEF-treatment and further dewatered afterwards to approximately 25% w/w before extraction. PEF-treatment with an energy input of 1.5 MJ per kilogram of dry m…
Assessment of genetically modified maize MON 87403 for food and feed uses, import and processing, under Regulation (EC) No 1829/2003 (application EFS…
2018
GMO; maize (Zea mays); MON 87403; ear biomass; Regulation (EC) No 1829/2003; International audience; aize MON 87403 was developed to increase ear biomass at early reproductive phase through the expression of a modified AtHB17 gene from Arabidopsis thaliana, encoding a plant transcription factor of the HD-Zip II family. The molecular characterisation data and bioinformatic analyses did not identify issues requiring assessment for food and feed safety. No statistically significant differences in the agronomic and phenotypic characteristics tested between maize MON 87403 and its conventional counterpart were identified. The compositional analysis of maize MON 87403 did not identify differences…
Boosting Biomass Quantity and Quality by Improved Mixotrophic Culture of the Diatom Phaeodactylum tricornutum
2021
Diatoms are photoautotrophic unicellular algae and are among the most abundant, adaptable, and diverse marine phytoplankton. They are extremely interesting not only for their ecological role but also as potential feedstocks for sustainable biofuels and high-value commodities such as omega fatty acids, because of their capacity to accumulate lipids. However, the cultivation of microalgae on an industrial scale requires higher cell densities and lipid accumulation than those found in nature to make the process economically viable. One of the known ways to induce lipid accumulation in Phaeodactylum tricornutum is nitrogen deprivation, which comes at the expense of growth inhibition and lower c…
Characterization of a β-glucosidase isolated from an alpeorujo strain of Candida adriatica
2017
ABSTRACTA β-glucosidase-producing strain, Candida adriatica CECT13142, was isolated from olive oil wastes (alpeorujo) and identified by PCR/restriction fragment length polymorphism of the rDNA internal transcribed spacer and sequence analysis of the D1/D2 region of the 26S rRNA gene techniques. The enzyme was purified by sequential chromatography on DEAE-cellulose and Sephadex G-100. The relative molecular mass of the enzyme was estimated to be 50 kDa by SDS-PAGE. The hydrolytic activity of the β-glucosidase had an optimum pH of 8.2 and an optimum temperature of 40°C. The enzyme displayed high substrate specificity and high catalytic efficiency (Km 0.85 mM, Vmax 12.5 U/g of cells) for p-nit…