scholarly journals Enzymatic preparation and characterization of soybean lecithin-based emulsifiers

2016 ◽  
Vol 67 (4) ◽  
pp. 168 ◽  
Author(s):  
R. C. Reddy Jala ◽  
B. Chen ◽  
H. Li ◽  
Y. Zhang ◽  
L-Z Cheong ◽  
...  
Keyword(s):  
Fatty Acid Composition ◽  
Calcium Ion ◽  
Soybean Lecithin ◽  
Low Ph ◽  
Enzymatic Preparation ◽  
High Calcium ◽  
Acidic Conditions ◽  
Phospholipid Distribution ◽  
Enzymatic Methods

Simple enzymatic methods were developed for the synthesis of lysolecithin, glycerolyzed lecithin and hydrolyzed lecithin. The products were characterized in terms of their acetone insoluble matter, hexane insoluble matter, moisture, phospholipid distribution and fatty acid composition. The HLB value ranges of different products with different acid values were detected. The efficiency of optimally hydrolyzed lecithin was examined at high calcium ion, low pH, and aqueous solutions and compared with commercially available standard lecithin-based emulsifiers. Overall, lysolecithin powder was proven to be the best emulsifier even at strong and medium acidic conditions.

Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple

2018 ◽  
Vol 39 (4) ◽  
pp. 474-482
Author(s):  
Hoang Thi Le Thuong ◽  
Nguyen Quang Hao ◽  
Tran Thi Thuy
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Ph ◽  
Yeast Strains ◽  
Biological Studies ◽  
Taxonomic Characterization

Eight yeast strains (denoted as D1 to D8) were isolated from samples of natural fermented pineapple. Strain D8 showed highest alcoholic production at low pH and special aroma of pineapple has been chosen for further study. Taxonomic characterization of strain D8 using morphological, biochemical and molecular biological studies confirmed that strain D8  belong to Saccharomycetaceae family, Saccharomycetales order and Saccharomyces cerevisiae species. Therefore, we named this strain as Saccharomyces cerevisiae D8 for further study on Brandy production from pineapple. Citation: Hoang Thi Le Thuong, Nguyen Quang Hao, Tran Thi Thuy, 2017. Taxonomic characterization and identification of Saccharomyces cerevisiae D8 for brandy production from pineapple. Tap chi Sinh hoc, 39(4): 474- 482. DOI: 10.15625/0866-7160/v39n4.10864.*Corresponding author: [email protected] Received 5 December 2016, accepted 12 August 2017

scholarly journals Mineralogical and Microstructure Analysis for Characterization and Provenance of Ceramic Artifacts from Late Helladic Kastrouli Settlement, Delphi (Central Greece)

Geosciences ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 36
Author(s):  
Vayia Xanthopoulou ◽  
Ioannis Iliopoulos ◽  
Ioannis Liritzis
Keyword(s):  
Raw Materials ◽  
Analytical Techniques ◽  
Sem Analysis ◽  
Petrographic Analysis ◽  
Ceramic Assemblage ◽  
Thin Sections ◽  
Central Greece ◽  
High Calcium ◽  
Local Geology

The present study deals with the characterization of a ceramic assemblage from the Late Mycenaean (Late Helladic III) settlement of Kastrouli, at Desfina near Delphi, Central Greece using various analytical techniques. Kastrouli is located in a strategic position supervising the Mesokampos plateau and the entire peninsula and is related to other nearby coeval settlements. In total 40 ceramic sherds and 8 clay raw materials were analyzed through mineralogical, petrographic and microstructural techniques. Experimental briquettes (DS) made from clayey raw materials collected in the vicinity of Kastrouli, were fired under temperatures (900 and 1050 °C) in oxidizing conditions for comparison with the ancient ceramics. The petrographic analysis performed on thin sections prepared from the sherds has permitted the identification of six main fabric groups and a couple of loners. The aplastic inclusions recognized in all fabric groups but one confirmed the local provenance since they are related to the local geology. Fresh fractures of representative sherds were further examined under a scanning electron microscope (SEM/EDS) helping us to classify them into calcareous (CaO > 6%) and non-calcareous (CaO < 6%) samples (low and high calcium was noted in earlier pXRF data). Here, the ceramic sherds with broad calcium separation are explored on a one-to-one comparison on the basis of detailed mineralogical microstructure. Moreover, their microstructure was studied, aiming to estimate their vitrification stage. The mineralogy of all studied samples was determined by means of X-ray powder diffraction (XRPD), permitting us to test the validity of the firing temperatures revealed by the SEM analysis. The results obtained through the various analytical techniques employed are jointly assessed in order to reveal potters’ technological choices.

scholarly journals Immortalization and Characterization of Rat Lingual Keratinocytes in a High-Calcium and Feeder-Free Culture System Using ROCK Inhibitor Y-27632

2021 ◽  
Vol 22 (13) ◽  
pp. 6782
Author(s):  
Zixing Chen ◽  
Wenmeng He ◽  
Thomas Chun Ning Leung ◽  
Hau Yin Chung
Keyword(s):  
Calcium Imaging ◽  
Cultured Cells ◽  
Rho Kinase ◽  
Culture Method ◽  
Taste Bud ◽  
Label Free ◽  
Sprague Dawley ◽  
Rock Inhibitor ◽  
High Calcium

Cultured keratinocytes are desirable models for biological and medical studies. However, primary keratinocytes are difficult to maintain, and there has been little research on lingual keratinocyte culture. Here, we investigated the effect of Y-27632, a Rho kinase (ROCK) inhibitor, on the immortalization and characterization of cultured rat lingual keratinocyte (RLKs). Three Y-27632–supplemented media were screened for the cultivation of RLKs isolated from Sprague–Dawley rats. Phalloidin staining and TUNEL assay were applied to visualize cytoskeleton dynamics and cell apoptosis following Y-27632 removal. Label-free proteomics, RT-PCR, calcium imaging, and cytogenetic studies were conducted to characterize the cultured cells. Results showed that RLKs could be conditionally immortalized in a high-calcium medium in the absence of feeder cells, although they did not exhibit normal karyotypes. The removal of Y-27632 from the culture medium led to reversible cytoskeletal reorganization and nuclear enlargement without triggering apoptosis, and a total of 239 differentially expressed proteins were identified by proteomic analysis. Notably, RLKs derived from the non-taste epithelium expressed some molecular markers characteristic of taste bud cells, yet calcium imaging revealed that they rarely responded to tastants. Collectively, we established a high-calcium and feeder-free culture method for the long-term maintenance of RLKs. Our results shed some new light on the immortalization and differentiation of lingual keratinocytes.

scholarly journals Identification and characterization of a second 4,4′-dibenzamido-2,2′-stilbenedisulphonate (DBDS)-binding site on band 3 and its relationship with the anion/proton co-transport function

2005 ◽  
Vol 388 (1) ◽  
pp. 343-353 ◽  
Author(s):  
James M. SALHANY ◽  
Karen S. CORDES ◽  
Renee L. SLOAN
Keyword(s):  
Binding Site ◽  
Proton Transport ◽  
Chloride Concentration ◽  
Band 3 ◽  
Low Ph ◽  
Binding Mechanism ◽  
Access Channel ◽  
Binding Kinetic ◽  
Transport Site

Band 3 mediates both electroneutral AE (anion exchange) and APCT (anion/proton co-transport). Protons activate APCT and inhibit AE with the same pK (∼5.0). SDs (stilbenedisulphonates) bind to a primary, high-affinity site on band 3 and inhibit both AE and APCT functions. In this study, we present fluorescence and kinetic evidence showing that lowering the pH activates a second site on band 3, which binds DBDS (4,4′-dibenzamido-2,2′-stilbenedisulphonate) independently of chloride concentration, and that DBDS binding to the second site inhibits the APCT function of band 3. Activation of the second site correlated with loss of chloride binding to the transport site, thus explaining the lack of competition. The kinetics of DBDS binding at the second site could be simulated by a slow-transition, two-state exclusive binding mechanism (R0↔T0+D↔TD↔RD, where D represents DBDS, R0 and T0 represent alternate conformational states at the second DBDS-binding site, and TD and RD are the same two states with ligand DBDS bound), with a calculated overall Kd of 3.9 μM and a T0+D↔TD dissociation constant of 55 nM. DBDS binding to the primary SD site inhibited approx. 94% of the proton transport at low pH (KI=68.5±11.8 nM). DBDS binding to the second site inhibited approx. 68% of the proton transport (KI=7.27±1.27 μM) in a band 3 construct with all primary SD sites blocked through selective cross-linking by bis(sulphosuccinimidyl)suberate. DBDS inhibition of proton transport at the second site could be simulated quantitatively within the context of the slow-transition, two-state exclusive binding mechanism. We conclude that band 3 contains two DBDS-binding sites that can be occupied simultaneously at low pH. The binding kinetic and transport inhibition characteristics of DBDS interaction with the second site suggest that it may be located within a gated access channel leading to the transport site.

FT-IR and micro-Raman spectroscopic characterization of minerals in high-calcium coal ashes

2018 ◽  
Vol 91 (3) ◽  
pp. 389-396 ◽  
Author(s):  
Yanshan Yin ◽  
Jie Yin ◽  
Wei Zhang ◽  
Hong Tian ◽  
Zhangmao Hu ◽  
...  
Keyword(s):  
Spectroscopic Characterization ◽  
Raman Spectroscopic ◽  
High Calcium ◽  
Ft Ir ◽  
Coal Ashes

scholarly journals Aromatic and Sensory Characterization of Maturana Blanca Wines Made with Different Technologies

Beverages ◽  
2021 ◽  
Vol 7 (1) ◽  
pp. 10
Author(s):  
Ana Naranjo ◽  
Leticia Martínez-Lapuente ◽  
Belén Ayestarán ◽  
Zenaida Guadalupe ◽  
Irene Pérez ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Sensory Analysis ◽  
Low Ph ◽  
Ethyl Esters ◽  
Vitis Vinifera L ◽  
White Variety ◽  
White Wines ◽  
Mass Detector ◽  
Oak Barrels

Vitis vinífera L. cv. Maturana Blanca is an autochthonous minor variety recently recovered in the Rioja Qualified Denomination of Origin (D.O.Ca Rioja, Spain) for the production of monovarietal white wines with singular and differentiated characteristics. In this paper, Maturana Blanca wines made with different technologies were analyzed by sensory analysis and aromatic profile by gas chromatography-mass detector. Maturana Blanca wines were characterized by low pH, high acidity, and yellowish tonalities. The compounds that most influenced the aroma of Maturana Blanca wines were those related to fruity (acetates and ethyl esters), floral aromas (2-phenylethanol), and spicy notes (γ-decalactone). These wines were mainly characterized by volatile compounds of fruity aromas of banana and apple. The use of pre-fermentative maceration increased the concentration of ethyl esters and acetates and produced wines with higher odor activity values, indicating a greater aromatic intensity. The aromatic profile of Maturana Blanca wines fermented in oak barrels showed a greater complexity as they were also characterized by the presence of important amounts of furfural, whiskey lactone, and eugenol. The sensory analysis confirmed the results obtained in the aromatic analysis, and described the wines as fresh and balanced in mouth, with notes of acidity and medium to high persistence. These results will contribute to a better knowledge of this white variety.

scholarly journals Characterization of Lassa Virus Cell Entry and Neutralization with Lassa Virus Pseudoparticles

2009 ◽  
Vol 83 (7) ◽  
pp. 3228-3237 ◽  
Author(s):  
François-Loic Cosset ◽  
Philippe Marianneau ◽  
Geraldine Verney ◽  
Fabrice Gallais ◽  
Noel Tordo ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Neutralizing Antibodies ◽  
Cell Attachment ◽  
Low Ph ◽  
Cell Entry ◽  
Lassa Virus ◽  
Ph Optimum ◽  
Humoral Immune

ABSTRACT The cell entry and humoral immune response of the human pathogen Lassa virus (LV), a biosafety level 4 (BSL4) Old World arenavirus, are not well characterized. LV pseudoparticles (LVpp) are a surrogate model system that has been used to decipher factors and routes involved in LV cell entry under BSL2 conditions. Here, we describe LVpp, which are highly infectious, with titers approaching those obtained with pseudoparticles displaying G protein of vesicular stomatitis virus and their the use for the characterization of LV cell entry and neutralization. Upon cell attachment, LVpp utilize endocytic vesicles for cell entry as described for many pH-dependent viruses. However, the fusion of the LV glycoproteins is activated at unusually low pH values, with optimal fusion occurring between pH 4.5 and 3, a pH range at which fusion characteristics of viral glycoproteins have so far remained largely unexplored. Consistent with a shifted pH optimum for fusion activation, we found wild-type LV and LVpp to display a remarkable resistance to exposure to low pH. Finally, LVpp allow the fast and quantifiable detection of neutralizing antibodies in human and animal sera and will thus facilitate the study of the humoral immune response in LV infections.

Biochemical characterization of a cortexless mutant of a variant of Bacillus cereus

1976 ◽  
Vol 22 (7) ◽  
pp. 1007-1012 ◽  
Author(s):  
Susanne M. Pearce
Keyword(s):  
Cell Wall ◽  
Fatty Acid Composition ◽  
Fatty Acid ◽  
Bacillus Cereus ◽  
Biochemical Characterization ◽  
Diaminopimelic Acid ◽  
Peptidoglycan Synthesis ◽  
Biochemical Lesion ◽  
Do So

Previous studies on this cortexless mutant of Bacillus cereus var. alesti indicated that the forespore membrane was the site of the biochemical lesion. This hypothesis is supported by the results presented here: fatty acid composition of sporulating cells of the mutant is altered, while in vegetative cells it is comparable to the parent; soluble precursors of peptidoglycan synthesis are accumulated in the mutant, at the time of cortex formation; homogenates of the mutant prepared at the time of cortex formation are unable to incorporate tritiated diaminopimelic acid into peptidoglycan, while homogenates of cells forming germ cell wall do so to an extent comparable to that of the parent; lipid-linked intermediates are formed by the mutant as in the parent. Apparently the mutant is unable either to transfer disaccharide penta-peptide units from the carrier lipid to the growing peptidoglycan acceptor, or to transport lipid-linked intermediates across the forespore membrane.

scholarly journals Characterization of the Physical, Chemical, and Adsorption Properties of Coal-Fly-Ash–Hydroxyapatite Composites

Minerals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 774
Author(s):  
Eleonora Sočo ◽  
Dorota Papciak ◽  
Magdalena M. Michel ◽  
Dariusz Pająk ◽  
Andżelika Domoń ◽  
...  
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Thermal Power ◽  
Synthesis Conditions ◽  
High Calcium ◽  
Ft Ir ◽  
Ir Analysis ◽  
Wet Synthesis

(1) Hydroxyapatite (Hap), which can be obtained by several methods, is known to be a good adsorbent. Coal fly ash (CFA) is a commonly reused byproduct also used in environmental applications as an adsorbent. We sought to answer the following question: Can CFA be included in the method of Hap wet synthesis to produce a composite capable of adsorbing both heavy metals and dyes? (2) High calcium lignite CFA from the thermal power plant in Bełchatów (Poland) was used as the base to prepare CFA–Hap composites. Four types designated CFA–Hap1–4 were synthesized via the wet method of in situ precipitation. The synthesis conditions differed in terms of the calcium reactants used, pH, and temperature. We also investigated the equilibrium adsorption of Cu(II) and rhodamine B (RB) on CFA–Hap1–4. The data were fitted using the Langmuir, Freundlich, and Redlich–Peterson models and validated using R2 and χ2/DoF. Surface changes in CFA–Hap2 following Cu(II) and RB adsorption were assessed using SEM, SE, and FT-IR analysis. (3) The obtained composites contained hydroxyapatite (Ca/P 1.67) and aluminosilicates. The mode of Cu(II) and RB adsorption could be explained by the Redlich–Peterson model. The CFA–Hap2 obtained using CFA, Ca(NO3)2, and (NH4)2HPO4 at RT and pH 11 exhibited the highest maximal adsorption capacity: 73.6 mg Cu/g and 87.0 mg RB/g. (4) The clear advantage of chemisorption over physisorption was indicated by the Cu(II)–CFA–Hap system. The RB molecules present in the form of uncharged lactone were favorably adsorbed even on strongly deprotonated CFA–Hap surfaces.

Electrokinetic Phenomena and Surface Characteristics of Fly Ash Particles

1984 ◽  
Vol 43 ◽  
Author(s):  
R. I. A. Malek ◽  
D. M. Roy
Keyword(s):  
Fly Ash ◽  
Surface Characteristics ◽  
Ionic Species ◽  
Point Of Zero Charge ◽  
Fly Ashes ◽  
Electrokinetic Phenomena ◽  
Zeta Potentials ◽  
Low Calcium ◽  
High Calcium

AbstractThe zeta-potentials of two fly ashes were studied (high-calcium and low-calcium). It was found that they possess a point of charge reversal at pH = 10.5 to 12. The point of zero charge (low-calcium fly ash) was found to be at pH = 5. Furthermore, it shifted to more acidic values after the fly ash is aged in several calcium-containing solutions. The surficial changes that could happen when mixing fly ashes with cement and concrete were further evaluated by aging fly ashes in different solutions: Ca(OH)2, CaSO4·2H2O, NaOH and water solutions. Information from analyses for different ionic species in the solutions and characterization of the solid residues (XRD and SEM) was used in tentative explanations for the different behavior of the two types of fly ash in cementitious mixtures and concrete.

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