scholarly journals Rhodosporidium sp. DR37: a novel strain for production of squalene in optimized cultivation conditions

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Shahryar Shakeri ◽  
Farshad Khoshbasirat ◽  
Mahmood Maleki
Keyword(s):  
Total Lipid ◽  
Large Scale ◽  
Consumption Rate ◽  
Accumulation Rate ◽  
Mangrove Ecosystem ◽  
Specific Cell ◽  
Cultivation Conditions ◽  
Sucrose Consumption ◽  
Squalene Content ◽  
Specific Lipid

Abstract Background Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, a new strain of Rhodosporidium sp. was isolated and identified, and its potential was investigated for production of squalene under various cultivation conditions. Results In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on modified YEPD medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Also, squalene content was obtained as 13.9% of total lipid. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20% v/v), pH 7, 25 °C) allowed highest squalene accumulation (619 mg/L) and content (21.6% of total lipid) in Rhodosporidium sp. DR37. Moreover, kinetic parameters including maximum specific cell growth rate (μmax, h−1), specific lipid accumulation rate (qp, h−1), specific squalene accumulation rate (qsq, h−1) and specific sucrose consumption rate (qs, h−1) were determined in optimized medium as 0.092, 0.226, 0.036 and 0.010, respectively. Conclusions This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. These findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale. Graphic abstract

scholarly journals Rhodosporidium Sp. DR37: A Novel Strain For Production of Squalene in Optimized Cultivation Conditions

2021 ◽  
Author(s):  
Shahryar Shakeri ◽  
Farshad Khoshbasirat ◽  
Mahmood Maleki
Keyword(s):  
Total Lipid ◽  
Large Scale ◽  
Oleaginous Yeast ◽  
Mangrove Ecosystem ◽  
Cultivation Conditions ◽  
Carotenoid Production ◽  
First Report ◽  
Squalene Content

Abstract Background: Rhodosporidium strain, a well-known oleaginous yeast, has been widely used as a platform for lipid and carotenoid production. However, the production of squalene for application in lipid-based biofuels is not reported in this strain. Here, we isolated and identified newly strain of Rhodosporidium sp. DR37 and investigated its potential for production of squalene under various cultivation conditions.Results: In the present study, Rhodosporidium sp. DR37 was isolated from mangrove ecosystem and its potential for squalene production was assessed. When Rhodosporidium sp. DR37 was cultivated on non-optimized medium (20 g/L glucose, 5 g/L peptone, 5 g/L YE, 15 g/L agar, seawater (50% v/v), pH 7, 30 °C), 64 mg/L of squalene was produced. Significantly, use of optimized medium (20 g/L sucrose, 5 g/L peptone, seawater (20 % v/v), pH 7, 25 °C) allowed highest squalene accumulation in Rhodosporidium sp. DR37 (619 mg/L). The maximum squalene content was obtained as 21.6% of total lipid in comparison to the non-optimized medium (13.9% of total lipid).Conclusions: This study is the first report to employ marine oleaginous Rhodosporidium sp. DR37 for accumulation of squalene in optimized medium. Our findings provide the potential of Rhodosporidium sp. DR37 for production of squalene as well as lipid and carotenoids for biofuel applications in large scale.

Daphnetin Ameliorates Corticosterone-Induced Depressive-Like Behavior and Oxidative Stress in Mice Via Nuclear Factor Erythroid 2-Related Factor/Heme Oxygenase-1 Pathway

2021 ◽  
Vol 19 (4) ◽  
pp. 470-476
Author(s):  
Chao Liu ◽  
Chao Liang ◽  
Jie Huang
Keyword(s):  
Oxidative Stress ◽  
Consumption Rate ◽  
Tail Suspension Test ◽  
Protein Carbonyl ◽  
Heme Oxygenase 1 ◽  
Related Factor ◽  
Sucrose Consumption ◽  
Markers Of Oxidative Stress ◽  
Swimming Test ◽  
And Oxidative Stress

We have investigated the effect of daphnetin on depressive-like behavior and oxidative stress caused by corticosterone in mice. To this end, we have analyzed the effect of corticosterone alone and combination of corticosterone and daphnetin on three behavioral indices of depressive-like behavior - sucrose consumption rate, forced swimming test, and tail suspension test as well as biochemical markers of oxidative stress - malondialdehyde, nitrite, protein carbonyl, nonprotein sulfhydryl and glutathione contents as well as hippocampal cell apoptosis. The results support the conclusion that daphnetin diminished corticosterone induced depressive like behavior and oxidative stress by activating Nrf2/HO-1 pathway.

scholarly journals Deconstructing Gastrulation at the Single Cell Level

2021 ◽  
Author(s):  
Tomer Stern ◽  
Sebastian J Streichan ◽  
Stanislav Y Shvartsman ◽  
Eric F Wieschaus
Keyword(s):  
Large Scale ◽  
Drosophila Embryo ◽  
Cell Segmentation ◽  
Model Organisms ◽  
Specific Cell ◽  
Cell Behaviors ◽  
Animal Development ◽  
Wide Range ◽  
Cell Groups ◽  
Epithelial Sheets

Gastrulation movements in all animal embryos start with regulated deformations of patterned epithelial sheets. Current studies of gastrulation use a wide range of model organisms and emphasize either large-scale tissue processes or dynamics of individual cells and cell groups. Here we take a step towards bridging these complementary strategies and deconstruct early stages of gastrulation in the entire Drosophila embryo, where transcriptional patterns in the blastoderm give rise to region-specific cell behaviors. Our approach relies on an integrated computational framework for cell segmentation and tracking and on efficient algorithms for event detection. Our results reveal how thousands of cell shape changes, divisions, and intercalations drive large-scale deformations of the patterned blastoderm, setting the stage for systems-level dissection of a pivotal step in animal development.

scholarly journals Human Pluripotent Stem Cell Culture: Current Status, Challenges, and Advancement

2018 ◽  
Vol 2018 ◽  
pp. 1-17 ◽  
Author(s):  
Sushrut Dakhore ◽  
Bhavana Nayer ◽  
Kouichi Hasegawa
Keyword(s):  
Stem Cells ◽  
Cell Culture ◽  
Pluripotent Stem Cells ◽  
Large Scale ◽  
Embryonic Stem ◽  
Current Status ◽  
Specific Cell ◽  
Therapeutic Applications ◽  
Proliferative Ability

Over the past two decades, human embryonic stem cells (hESCs) have gained attention due to their pluripotent and proliferative ability which enables production of almost all cell types in the human body in vitro and makes them an excellent tool to study human embryogenesis and disease, as well as for drug discovery and cell transplantation therapies. Discovery of human-induced pluripotent stem cells (hiPSCs) further expanded therapeutic applications of human pluripotent stem cells (PSCs). hPSCs provide a stable and unlimited original cell source for producing suitable cells and tissues for downstream applications. Therefore, engineering the environment in which these cells are grown, for stable and quality-controlled hPSC maintenance and production, is one of the key factors governing the success of these applications. hPSCs are maintained in a particular niche using specific cell culture components. Ideally, the culture should be free of xenobiotic components to render hPSCs suitable for therapeutic applications. Substantial efforts have been put to identify effective components, and develop culture conditions and protocols, for their large-scale expansion without compromising on quality. In this review, we discuss different media, their components and functions, including specific requirements to maintain the pluripotent and proliferative ability of hPSCs. Understanding the role of culture components would enable the development of appropriate conditions to promote large-scale, quality-controlled expansion of hPSCs thereby increasing their potential applications.

scholarly journals Large-scale co-aggregation of fluorescent lipid probes with cell surface proteins.

1994 ◽  
Vol 125 (4) ◽  
pp. 795-802 ◽  
Author(s):  
J L Thomas ◽  
D Holowka ◽  
B Baird ◽  
W W Webb
Keyword(s):  
Cell Surface ◽  
Large Scale ◽  
Plasma Membranes ◽  
Immunoglobulin E ◽  
Large Fraction ◽  
Surface Antigens ◽  
Specific Cell ◽  
Cell Surface Antigens ◽  
Receptor Complexes ◽  
Ige Receptors

Large scale aggregation of fluorescein-labeled immunoglobulin E (IgE) receptor complexes on the surface of RBL cells results in the co-aggregation of a large fraction of the lipophilic fluorescent probe 3,3'-dihexadecylindocarbocyanine (diI) that labels the plasma membranes much more uniformly in the absence of receptor aggregation. Most of the diI molecules that are localized in patches of aggregated receptors have lost their lateral mobility as determined by fluorescence photobleaching recovery. The diI outside of patches is mobile, and its mobility is similar to that in control cells without receptor aggregates. It is unlikely that the co-aggregation of diI with IgE receptors is due to specific interactions between these components, as two other lipophilic probes of different structures are also observed to redistribute with aggregated IgE receptors, and aggregation of two other cell surface antigens also results in the coredistribution of diI at the RBL cell surface. Quantitative analysis of CCD images of labeled cells reveals some differences in the spatial distributions of co-aggregated diI and IgE receptors. The results indicate that cross-linking of specific cell surface antigens causes a substantial change in the organization of the plasma membrane by redistributing pre-existing membrane domains or causing their formation.

scholarly journals Ice Flow Along AN Iagp Flow Line, Wilkes Land, Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 346 ◽  
Author(s):  
N.W. Young ◽  
D. SheehY ◽  
T. Hamley
Keyword(s):  
Strain Rate ◽  
Large Scale ◽  
Flow Line ◽  
Accumulation Rate ◽  
Surface Profile ◽  
Ice Thickness ◽  
Shear Strain Rate ◽  
Surface Slope ◽  
Ice Flow ◽  
Wilkes Land

Trilateration and single line surveys have been made to about 900 km inland of Casey, Wilkes Land, to measure surface elevation, ice thickness, horizontal velocity, and other parameters. On the large scale the velocity U increases smoothly from 8 m a−1, 800 km inland, to 280 m a−1 inland of the fast outlet streams. This increase in velocity is associated with a corresponding increase in the large-scale smoothed (over about 30 ice thicknesses) basal shear stress τb from 0.4 to 1.5 bar. The mean shear strain-rate through the ice sheet U/Z = kτb4 , where Z is the ice thickness (range 4 500 to 1 700 m). At scales of one to several ice thicknesses large variations occur in surface slope and ice thickness without proportionally large velocity variations, because of the effect of the longitudinal stress. Detailed measurements made over a 30 km section indicated that the surface longitudinal strain-rate gradient varied from -1.7 to +1.3×l0−6 a−1 m−1 along with variations in surface slope of from -3.5 to +1.5%. A multilayer model, based on the solution of the biharmonic equation for the stream function, was used in a study of the ice flow associated with these surface undulations. Given the bedrock topography and large-scale flow parameters, the model closely predicted the measured surface profile when the variation of the surface accumulation rate over an undulation was also considered.

scholarly journals Tidal wetland resilience to sea level rise increases their carbon sequestration capacity in United States

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Faming Wang ◽  
Xiaoliang Lu ◽  
Christian J. Sanders ◽  
Jianwu Tang
Keyword(s):  
Climate Change ◽  
United States ◽  
Sea Level Rise ◽  
Sea Level ◽  
Large Scale ◽  
Accumulation Rate ◽  
C Sequestration ◽  
Tidal Wetlands ◽  
Tidal Wetland ◽  
Climate Change Scenarios

AbstractCoastal wetlands are large reservoirs of soil carbon (C). However, the annual C accumulation rates contributing to the C storage in these systems have yet to be spatially estimated on a large scale. We synthesized C accumulation rate (CAR) in tidal wetlands of the conterminous United States (US), upscaled the CAR to national scale, and predicted trends based on climate change scenarios. Here, we show that the mean CAR is 161.8 ± 6 g Cm−2 yr−1, and the conterminous US tidal wetlands sequestrate 4.2–5.0 Tg C yr−1. Relative sea level rise (RSLR) largely regulates the CAR. The tidal wetland CAR is projected to increase in this century and continue their C sequestration capacity in all climate change scenarios, suggesting a strong resilience to sea level rise. These results serve as a baseline assessment of C accumulation in tidal wetlands of US, and indicate a significant C sink throughout this century.

Global wind-induced change of deep-sea sediment budgets, new ocean production and CO 2 reservoirs ca . 3.3-2.35 Ma BP

1988 ◽  
Vol 318 (1191) ◽  
pp. 487-504 ◽  
Keyword(s):  
Large Scale ◽  
Accumulation Rate ◽  
Sediment Accumulation ◽  
Distribution Patterns ◽  
Trade Wind ◽  
Accumulation Rates ◽  
Deep Sea Sediment ◽  
Late Pliocene ◽  
High Productivity ◽  
Sediment Fraction

The late Pliocene phase of large-scale climatic deterioration about 3.2-2.4 Ma BP is well documented in a number of (benthic) δ 18 O records. To test the global implications of this event, we have mapped the distribution patterns of various sediment variables in the Pacific and Atlantic Oceans during two time slices, 3.4-3.18 and 2.43-2.33 Ma BP. The changes of bulk sedimentation and bulk sediment accumulation rates are largely explained by the variations of CaCO 3 -accumulation rates (and the accumulation rates of the complementary siliciclastic sediment fraction near continents in higher latitudes). During the late Pliocene, the CaCO 3 -accumulation rate increased along the equatorial Pacific and Atlantic and in the northeastern Atlantic, but decreased elsewhere. The accumulation rate of organic carbon (C org ) and net palaeoproductivity also increased below the high-productivity belts along the equator and the eastern continental margins. From these patterns we may conclude that (trade-) wind- induced upwelling zones and upwelling productivity were much enhanced during that time. This change led to an increased transfer of CO 2 from the surface ocean to the ocean deep water and to a reduction of evaporation, which resulted in an aridification of the Saharan desert belt as depicted in the dust sediments off northwest Africa.

scholarly journals Spatial Distribution of Crusts in Antarctic and Greenland Snowpacks and Implications for Snow and Firn Studies

2021 ◽  
Vol 9 ◽  
Author(s):  
Alexander H. Weinhart ◽  
Sepp Kipfstuhl ◽  
Maria Hörhold ◽  
Olaf Eisen ◽  
Johannes Freitag
Keyword(s):  
Spatial Distribution ◽  
Large Scale ◽  
Accumulation Rate ◽  
Sampling Site ◽  
Stable Water Isotopes ◽  
High Accumulation ◽  
Surface Mass ◽  
Antarctic Plateau ◽  
Wide Range ◽  
Surface Snow

The occurrence of snowpack features has been used in the past to classify environmental regimes on the polar ice sheets. Among these features are thin crusts with high density, which contribute to firn stratigraphy and can have significant impact on firn ventilation as well as on remotely inferred properties like accumulation rate or surface mass balance. The importance of crusts in polar snowpack has been acknowledged, but nonetheless little is known about their large-scale distribution. From snow profiles measured by means of microfocus X-ray computer tomography we created a unique dataset showing the spatial distribution of crusts in snow on the East Antarctic Plateau as well as in northern Greenland including a measure for their local variability. With this method, we are able to find also weak and oblique crusts, to count their frequency of occurrence and to measure the high-resolution density. Crusts are local features with a small spatial extent in the range of tens of meters. From several profiles per sampling site we are able to show a decreasing number of crusts in surface snow along a traverse on the East Antarctic Plateau. Combining samples from Antarctica and Greenland with a wide range of annual accumulation rate, we find a positive correlation (R2 = 0.89) between the logarithmic accumulation rate and crusts per annual layer in surface snow. By counting crusts in two Antarctic firn cores, we can show the preservation of crusts with depth and discuss their temporal variability as well as the sensitivity to accumulation rate. In local applications we test the robustness of crusts as a seasonal proxy in comparison to chemical records like impurities or stable water isotopes. While in regions with high accumulation rates the occurrence of crusts shows signs of seasonality, in low accumulation areas dating of the snowpack should be done using a combination of volumetric and stratigraphic elements. Our data can bring new insights for the study of firn permeability, improving of remote sensing signals or the development of new proxies in snow and firn core research.

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