The Experts below are selected from a list of 19137 Experts worldwide ranked by ideXlab platform
Vesna M Vucurovic - One of the best experts on this subject based on the ideXlab platform.
-
bioethanol production from sugar beet molasses and thick juice using saccharomyces cerevisiae immobilized on maize stem Ground Tissue
Fuel, 2012Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:Abstract The potential of by-products and intermediate products of sugar beet processing as raw materials for bioethanol production in Vojvodina region has a big scope in view of the demand of ethanol as an alternative for fossil fuels. Also, from ecological point of view, use of agricultural waste as carriers for cells immobilization is justifiable. The biocatalyst prepared by immobilization of Saccharomyces cerevisiae on maize stem Ground Tissue was used for batch fermentation of sugar beet molasses and thick juice under normal and very high gravity (VHG) conditions. Cell immobilization was observed by electron microscopy. The carrier was effective for cell immobilization and provided strength and stability to the yeast cell mass and functioned as a fortification against toxins and inhibitors, enabling efficient ethanol fermentation, particularly in VHG conditions. Three different initial glucose concentrations were tested: 100, 150 and 300 g/l. The maximum ethanol concentration of 83.20 g/l for molasses and 132.39 g/l for thick juice were achieved in VHG fermentation by immobilized cells, whereas the free yeast cells were unsuccessful in the same media. Taking into consideration significant process parameters sugar beet thick juice was found to be economically favorable, compared to molasses, particularly in the VHG fermentation process.
-
ethanol production from sugar beet molasses by s cerevisiae entrapped in an alginate maize stem Ground Tissue matrix
Enzyme and Microbial Technology, 2011Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:A new alginate-maize stem Ground Tissue matrix was developed as a Saccharomyces cerevisiae carrier for ethanol fermentation from sugar beet molasses. There were several fermentation procedures in the present study: using free cells and alginate-entrapped cells with and without maize stem Ground Tissue supplementation (F; F+C; AB; AB+C), and using a new combined alginate-maize stem Ground Tissue carrier (ABC). It was found that addition of maize stem Ground Tissue meal (C), with honeycomb configuration, provided high surface areas for cell attachment and biofilm growth, and also increased alginate matrix porosity, enabling better mass transfer characteristic, better physical strength and stability of beads. The highest values of process parameters were obtained in the case of new carrier (ABC): the ethanol concentration of 60.36 g/l, percentage of the theoretical ethanol yield of 96.56%, ethanol yield of 0.493 g/g and the volumetric ethanol productivity of 2.51 g/lh. The medium supplementation with maize stem Ground Tissue significantly decreased acetaldehyde and acetic acid content, did not affect fusel alcohol and ethylacetate content of the distillate.
Michael Kuhl - One of the best experts on this subject based on the ideXlab platform.
-
nanoparticle based measurements of ph and o2 dynamics in the rhizosphere of zostera marina l effects of temperature elevation and light dark transitions
Plant Cell and Environment, 2016Co-Authors: Kasper Elgetti Brodersen, Mads Lichtenberg, Michael Kuhl, Klaus KorenAbstract:Seagrasses can modulate the geochemical conditions in their immediate rhizosphere through the release of chemical compounds from their below-Ground Tissue. This is a vital chemical defence mechanism, whereby the plants detoxify the surrounding sediment. Using novel nanoparticle-based optical O2 and pH sensors incorporated in reduced and transparent artificial sediment, we investigated the spatio-temporal dynamics of pH and O2 within the entire rhizosphere of Zostera marina L. during experimental manipulations of light and temperature. We combined such measurements with O2 microsensor measurements of the photosynthetic productivity and respiration of seagrass leaves. We found pronounced pH and O2 microheterogeneity within the immediate rhizosphere of Z. marina, with higher below-Ground Tissue oxidation capability and rhizoplane pH levels during both light exposure of the leaf canopy and elevated temperature, where the temperature-mediated stimuli of biogeochemical processes seemed to predominate. Low rhizosphere pH microenvironments appeared to correlate with plant-derived oxic microzones stimulating local sulphide oxidation and thus driving local proton generation, although the rhizoplane pH levels generally where much higher than the bulk sediment pH. Our data show that Z. marina can actively alter its rhizosphere pH microenvironment alleviating the local H2S toxicity and enhancing nutrient availability in the adjacent sediment via geochemical speciation shift.
-
epiphyte cover on seagrass zostera marina l leaves impedes plant performance and radial o2 loss from the below Ground Tissue
Frontiers in Marine Science, 2015Co-Authors: Kasper Elgetti Brodersen, Mads Lichtenberg, Michael KuhlAbstract:The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL) surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins. We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-Ground radial O2 loss from roots (~1 mm from the root-apex) to elucidate how this below-Ground oxic microzone was affected by the presence of epiphytes. Epiphyte-cover on seagrass leaves (~21% areal cover) resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient) exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-Ground Tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap Tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion. Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-Ground Tissue.
-
a split flow chamber with artificial sediment to examine the below Ground microenvironment of aquatic macrophytes
Marine Biology, 2014Co-Authors: Kasper Elgetti Brodersen, Michael Kuhl, Daniel A Nielsen, Peter J RalphAbstract:We present a new experimental set-up enabling fine-scale examination of how changing environmental conditions affect the below-Ground biogeochemical microenvironment of aquatic macrophytes. By means of microsensor and planar optode technology, the influence of plant-mediated radial O2 release on the below-Ground chemical microenvironment of Zostera muelleri and Halophila ovalis was determined in high spatio-temporal resolution. The seagrass specimens were cultured in a new split flow chamber with artificial sediment made of a deoxygenated seawater–agar solution with added sulphide. Microelectrode measurements revealed radial O2 release from the root–shoot junction of both Z. muelleri and H. ovalis during both light stimulation and darkness, resulting in a rapid decrease in H2S concentration, and a significant drop in pH was observed within the plant-derived oxic microzone of Z. muelleri. No radial O2 release was detectable from the below-Ground Tissue of Z. muelleri during conditions of combined water-column hypoxia and darkness, leaving the plants more susceptible to sulphide invasion. The spatial O2 heterogeneity within the immediate rhizosphere of Z. muelleri was furthermore determined in two dimensions by means of planar optodes. O2 images revealed a decrease in the spatial extent of the plant-derived oxic microzone surrounding the below-Ground Tissue during darkness, supporting the microelectrode measurements. This new experimental approach can be applied to all rooted aquatic plants, as it allows for direct visual assessment of the below-Ground Tissue surface during microprofiling, while enabling modification of the above-Ground environmental conditions.
Radojka N Razmovski - One of the best experts on this subject based on the ideXlab platform.
-
bioethanol production from sugar beet molasses and thick juice using saccharomyces cerevisiae immobilized on maize stem Ground Tissue
Fuel, 2012Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:Abstract The potential of by-products and intermediate products of sugar beet processing as raw materials for bioethanol production in Vojvodina region has a big scope in view of the demand of ethanol as an alternative for fossil fuels. Also, from ecological point of view, use of agricultural waste as carriers for cells immobilization is justifiable. The biocatalyst prepared by immobilization of Saccharomyces cerevisiae on maize stem Ground Tissue was used for batch fermentation of sugar beet molasses and thick juice under normal and very high gravity (VHG) conditions. Cell immobilization was observed by electron microscopy. The carrier was effective for cell immobilization and provided strength and stability to the yeast cell mass and functioned as a fortification against toxins and inhibitors, enabling efficient ethanol fermentation, particularly in VHG conditions. Three different initial glucose concentrations were tested: 100, 150 and 300 g/l. The maximum ethanol concentration of 83.20 g/l for molasses and 132.39 g/l for thick juice were achieved in VHG fermentation by immobilized cells, whereas the free yeast cells were unsuccessful in the same media. Taking into consideration significant process parameters sugar beet thick juice was found to be economically favorable, compared to molasses, particularly in the VHG fermentation process.
-
ethanol production from sugar beet molasses by s cerevisiae entrapped in an alginate maize stem Ground Tissue matrix
Enzyme and Microbial Technology, 2011Co-Authors: Radojka N Razmovski, Vesna M VucurovicAbstract:A new alginate-maize stem Ground Tissue matrix was developed as a Saccharomyces cerevisiae carrier for ethanol fermentation from sugar beet molasses. There were several fermentation procedures in the present study: using free cells and alginate-entrapped cells with and without maize stem Ground Tissue supplementation (F; F+C; AB; AB+C), and using a new combined alginate-maize stem Ground Tissue carrier (ABC). It was found that addition of maize stem Ground Tissue meal (C), with honeycomb configuration, provided high surface areas for cell attachment and biofilm growth, and also increased alginate matrix porosity, enabling better mass transfer characteristic, better physical strength and stability of beads. The highest values of process parameters were obtained in the case of new carrier (ABC): the ethanol concentration of 60.36 g/l, percentage of the theoretical ethanol yield of 96.56%, ethanol yield of 0.493 g/g and the volumetric ethanol productivity of 2.51 g/lh. The medium supplementation with maize stem Ground Tissue significantly decreased acetaldehyde and acetic acid content, did not affect fusel alcohol and ethylacetate content of the distillate.
Genlin Tian - One of the best experts on this subject based on the ideXlab platform.
-
tensile properties of moso bamboo phyllostachys pubescens and its components with respect to its fiber reinforced composite structure
Wood Science and Technology, 2010Co-Authors: Zhuoping Shao, Changhua Fang, Shengxia Huang, Genlin TianAbstract:Bamboo is a fiber-reinforced bio-composite since its culm wall is mainly composed of parenchymatous Ground Tissue in which vascular bundles are embedded. In order to analyze the mechanical properties of bamboo as a function of its components, tensile tests were performed on bamboo blocks and the corresponding volume fractions of fiber and parenchymatous Ground Tissue were measured. More significant linear relationships were found between tensile properties and volume fractions of the bamboo components. The tensile strength and modulus of elasticity of bamboo fiber and parenchymatous Tissue were estimated according to the linear equations obtained by regression analysis. The macrographs of fractured bamboo blocks and the micrographs of fracture surfaces obtained by scanning electron microscope were also analyzed. Further tensile tests on separated bamboo fiber bundles were analyzed. Results show that the tensile strength of bamboo fiber obtained from the tests on bamboo blocks was higher than that on separated fiber bundles. This might be due to the interaction between components in bamboo in which parenchymatous Ground Tissue can pass loads and distribute the stresses loaded on fibers.
-
mode i interlaminar fracture property of moso bamboo phyllostachys pubescens
Wood Science and Technology, 2009Co-Authors: Zhuoping Shao, Changhua Fang, Genlin TianAbstract:Bamboo is a unidirectional fiber-reinforced bio-composite. Once having cracks, the delaminating propagation is not controlled by the strength but by the interlaminar fracture toughness. In this paper, the behaviors of Mode I (crack opening mode) interlaminar fracture parallel to grain of moso bamboo (Phyllostachys pubescens) were studied. Based on energy theory, the Mode I interlaminar fracture toughness, G IC, was measured using the double cantilever beam specimens, and the fracture surfaces were examined under scanning electron microscope. The results show that: (1) the interlaminar fracture toughness of Mode I is the basic characteristic of bamboo material. The mean value of G IC = 358 J/m2 (coefficient of variation = 16.88%) represents the resistance arresting crack propagation. No significant difference was found for G IC among the specimens located at different heights of the bamboo. (2) Due to the low G IC of bamboo, the crack propagation parallel to grain developed easily. The crack was a self-similar fracture without fiber-bridging. On the fracture surfaces, smooth fibers and plane Ground Tissue were found at the extended area of Mode I fracture along the longitudinal direction. Under scanning electron microscope, it could be seen that the crack propagation developed along the longitudinal interface between fibers or Ground Tissue. It indicates that the longitudinal interface strength was weak among bamboo cells.
Kimberly L Gallagher - One of the best experts on this subject based on the ideXlab platform.
-
symplastic signaling instructs cell division cell expansion and cell polarity in the Ground Tissue of arabidopsis thaliana roots
Proceedings of the National Academy of Sciences of the United States of America, 2016Co-Authors: Ruthsabel Olexy, Yi Sang, Xu Chen, Kimberly L GallagherAbstract:Cell-to-cell communication is essential for the development and patterning of multicellular organisms. In plants, plasmodesmata (PD) provide direct routes for intercellular signaling. However, the role that PD-mediated signaling plays in plant development has not been fully investigated. To gain a comprehensive view of the role that symplastic signaling plays in Arabidopsis thaliana, we have taken advantage of a synthetic allele of CALLOSE SYNTHASE3 (icals3m) that inducibly disrupts cell-to-cell communication specifically at PD. Our results show that loss of symplastic signaling to and from the endodermis has very significant effects on the root, including an increase in the number of cell layers in the root and a misspecification of stele cells, as well as Ground Tissue. Surprisingly, loss of endodermal signaling also results in a loss of anisotropic elongation in all cells within the root, similar to what is seen in radially swollen mutants. Our results suggest that symplastic signals to and from the endodermis are critical in the coordinated growth and development of the root.
-
a plausible mechanism based upon short root movement for regulating the number of cortex cell layers in roots
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Shuang Wu, Sophia Henry, Fanchon Divol, Christophe Perin, Tomomi Hayashi, Simara Price, Germain Pauluzzi, Kimberly L GallagherAbstract:Formation of specialized cells and Tissues at defined times and in specific positions is essential for the development of multicellular organisms. Often this developmental precision is achieved through intercellular signaling networks, which establish patterns of differential gene expression and ultimately the specification of distinct cell fates. Here we address the question of how the SHORT-ROOT (SHR) proteins from Arabidopsis thaliana (AtSHR), Brachypodium distachyon (BdSHR), and Oryza sativa (OsSHR1 and OsSHR2) function in patterning the root Ground Tissue. We find that all of the SHR proteins function as mobile signals in A. thaliana and all of the SHR homologs physically interact with the AtSHR binding protein, SCARECOW (SCR). Unlike AtSHR, movement of the SHR homologs was not limited to the endodermis. Instead, the SHR proteins moved multiple cell layers and determined the number of cortex, not endodermal, cell layers formed in the root. Our results in A. thaliana are consistent with a mechanism by which the regulated movement of the SHR transcription factor determines the number of cortex cell layers produced in the roots of B. distachyon and O. sativa. These data also provide a new model for Ground Tissue patterning in A. thaliana in which the ability to form a functional endodermis is spatially limited independently of SHR.
-
the movement of the non cell autonomous transcription factor short root relies on the endomembrane system
Plant Journal, 2014Co-Authors: Kimberly L GallagherAbstract:Summary Plant cells are able to convey positional and developmental information between cells through the direct transfer of transcription factors. One well studied example of this is the SHORT-ROOT (SHR) protein, which moves from the stele into the neighboring Ground Tissue layer to specify endodermis. While it has been shown that SHR trafficking relies on plasmodesmata (PD), and interaction with the SHR INTERACTING EMBRYONIC LETHAL (SIEL) protein, little information is known about how SHR trafficking is controlled or how SIEL promotes the movement of SHR. Here we show that SHR can move from multiple different cell types in the root. Analysis of subcellular localization indicates that in the cytoplasm of root or leaf cells, SHR localizes to endosomes in a SIEL-dependent manner. Interference of early and late endosomes disrupts intercellular movement of SHR. Our findings reveal an essential role for the plant endomembrane, independent of secretion, in the intercellular trafficking of SHR.
