scholarly journals Speciation Analysis of Selenium in Candida utilis Yeast Cells Using HPLC-ICP-MS and UHPLC-ESI-Orbitrap MS Techniques

2018 ◽  
Vol 8 (11) ◽  
pp. 2050 ◽  
Author(s):  
Marek Kieliszek ◽  
Stanisław Błażejak
Keyword(s):  
Candida Utilis ◽  
Speciation Analysis ◽  
Yeast Cells ◽  
Future Research ◽  
Selenium Compounds ◽  
Icp Ms ◽  
Inorganic Selenium ◽  
Low Mass ◽  
Living Organisms ◽  
Orbitrap Ms

Selenium plays a key role in the proper metabolism of living organisms. The search for new selenium compounds opens up new possibilities for understanding selenometabolome in yeast cells. This study was aimed at the identification of compounds containing selenium in the feed yeasts Candida utilis ATCC 9950. Yeast biomass was kept in aqueous solutions enriched with inorganic selenium (20 mg·L−1) for 24 h. Speciation analysis of the element was performed using the HPLC-ICP-MS and UHPLC-ESI-Orbitrap MS techniques. The obtained selenium value in the yeast was 629 μg·g−1, while the selenomethionine value was 31.57 μg·g−1. The UHPLC-ESI-Orbitrap MS analysis conducted allowed for the identification of six selenium compounds: dehydro-selenomethionine-oxide, selenomethionine, selenomethionine-NH3, a Se-S conjugate of selenoglutathione-cysteine, methylthioselenoglutathione, and 2,3-DHP-selenocysteine-cysteine. In order to explain the structure of selenium compounds, the selected ions were subjected to fragmentation. The selenium compounds obtained with a low mass play a significant role in the metabolism of the compound. However, the bioavailability of such components and their properties have not been fully understood. The number of signals indicating the presence of selenium compounds obtained using the UHPLC-ESI-Orbitrap MS method was characterized by higher sensitivity than when using the HPLC-ICP-MS method. The obtained results will expand upon knowledge about the biotransformation of selenium in eukaryotic yeast cells. Future research should focus on understanding the entire selenium metabolism in cells and on the search for new transformation pathways for this element. This opens up new possibilities for obtaining functional food, rich in easily absorbable selenium sources, and constituting an alternative to dietary supplements based on this compound found primarily in inorganic form.

scholarly journals Accumulation of Selenium in Candida utilis Growing in Media of Increasing Concentration of this Element

2020 ◽  
Vol 10 (4) ◽  
pp. 1439 ◽  
Author(s):  
Marek Kieliszek ◽  
Anna Maria Kot ◽  
Kamil Piwowarek ◽  
Stanisław Błażejak
Keyword(s):  
Candida Utilis ◽  
Culture Medium ◽  
Dry Weight ◽  
Yeast Cells ◽  
Reciprocating Motion ◽  
Experimental Medium ◽  
Yeast Cultures ◽  
Cell Biomass ◽  
Icp Ms ◽  
Living Organisms

Selenium is considered an essential component of all living organisms. Studies on the enrichment of yeast cells with selenium, using the ability of cell biomass to bind this element, are being reported more and more. Yeast cultures were cultivated in YPD medium enriched with Na2SeO3 salts for 72 h at 28 °C on a shaker utilizing reciprocating motion. Selenium in cell biomass was determined with the use of ICP–MS. It was observed that the addition of selenium to the experimental medium (in the range of 4–100 mg/L) increased the content of this element in the yeast cell biomass. During the extension of cultivation time, the number of yeast cells and biomass yield exhibited a decreasing trend. Based on the obtained results, it was concluded that yeast cells exhibited the ability to accumulate selenium in both logarithmic and stationary growth phases. The dose of 20 and 30 mg/L of selenium in the culture medium meets the expectations in terms of both the content of selenium bound to yeast cells (1944 ± 110.8 μg/g dry weight) under 48-h cultivation. The obtained results confirmed that the Candida utilis ATCC 9950 strain exhibits the ability to bind selenium, which means that the biomass of these yeasts may be used as a natural source of selenium in the diet of humans and animals.

Speciation analysis of arsenic and selenium compounds by CE-dynamic reaction cell-ICP-MS

2010 ◽  
Vol 31 (13) ◽  
pp. 2272-2278 ◽  
Author(s):  
Meng-Wei Hsieh ◽  
Chen-Ling Liu ◽  
Jing-Huan Chen ◽  
Shiuh-Jen Jiang
Keyword(s):  
Speciation Analysis ◽  
Dynamic Reaction ◽  
Dynamic Reaction Cell ◽  
Reaction Cell ◽  
Selenium Compounds ◽  
Icp Ms

Development of anion-exchange high-performance liquid chromatography-inductively coupled plasma mass spectrometry methods for the speciation analysis of inorganic selenium and iodine in groundwater

2014 ◽  
Vol 6 (20) ◽  
pp. 8380-8387 ◽  
Author(s):  
Zhe Nie ◽  
Lingna Zheng ◽  
Weiyue Feng ◽  
Chunli Liu
Keyword(s):  
Inductively Coupled Plasma ◽  
High Performance ◽  
Speciation Analysis ◽  
Inductively Coupled ◽  
Groundwater Samples ◽  
Icp Ms ◽  
Inorganic Selenium ◽  
Plasma Mass Spectrometry ◽  
Ultra Trace ◽  
Hlw Repository

An HPLC-ICP-MS method for simultaneous speciation of selenium and iodine has been developed. Species in groundwater samples from a potential Chinese HLW repository site were determined at ultra-trace level.

scholarly journals Metabolic Response of the Yeast Candida utilis During Enrichment in Selenium

2020 ◽  
Vol 21 (15) ◽  
pp. 5287 ◽  
Author(s):  
Marek Kieliszek ◽  
Katarzyna Bierla ◽  
Javier Jiménez-Lamana ◽  
Anna Maria Kot ◽  
Jaime Alcántara-Durán ◽  
...  
Keyword(s):  
Candida Utilis ◽  
Metabolic Response ◽  
Thioredoxin Reductase ◽  
Dry Weight ◽  
Yeast Cells ◽  
Insoluble Protein ◽  
Glutathione S Transferase ◽  
Response To Stress ◽  
Insoluble Protein Fraction ◽  
Orbitrap Ms

Selenium (Se) was found to inhibit the growth of the yeast Candida utilis ATCC 9950. Cells cultured in 30 mg selenite/L supplemented medium could bind 1368 µg Se/g of dry weight in their structures. Increased accumulation of trehalose and glycogen was observed, which indicated cell response to stress conditions. The activity of antioxidative enzymes (glutathione peroxidase, glutathione reductase, thioredoxin reductase, and glutathione S-transferase) was significantly higher than that of the control without Se addition. Most Se was bound to water-insoluble protein fraction; in addition, the yeast produced 20–30 nm Se nanoparticles (SeNPs). Part of Se was metabolized to selenomethionine (10%) and selenocysteine (20%). The HPLC-ESI-Orbitrap MS analysis showed the presence of five Se compounds combined with glutathione in the yeast. The obtained results form the basis for further research on the mechanisms of Se metabolism in yeast cells.

Heterogeneity of Size and Distribution of Intramembrane Particles in the Plasma Membrane of Yeast

1977 ◽  
Vol 35 ◽  
pp. 596-597
Author(s):  
E. Keyhani
Keyword(s):  
Plasma Membrane ◽  
Candida Utilis ◽  
Synthetic Medium ◽  
Freeze Fracture ◽  
Translational Diffusion ◽  
Yeast Cells ◽  
Distilled Water ◽  
Intramembrane Particles ◽  
The Matrix ◽  
Water Cell

The matrix of biological membranes consists of a lipid bilayer into which proteins or protein aggregates are intercalated. Freeze-fracture techni- ques permit these proteins, perhaps in association with lipids, to be visualized in the hydrophobic regions of the membrane. Thus, numerous intramembrane particles (IMP) have been found on the fracture faces of membranes from a wide variety of cells (1-3). A recognized property of IMP is their tendency to form aggregates in response to changes in experi- mental conditions (4,5), perhaps as a result of translational diffusion through the viscous plane of the membrane. The purpose of this communica- tion is to describe the distribution and size of IMP in the plasma membrane of yeast (Candida utilis).Yeast cells (ATCC 8205) were grown in synthetic medium (6), and then harvested after 16 hours of culture, and washed twice in distilled water. Cell pellets were suspended in growth medium supplemented with 30% glycerol and incubated for 30 minutes at 0°C, centrifuged, and prepared for freeze-fracture, as described earlier (2,3).

scholarly journals Accumulation of Elements in Biodeposits on the Stone Surface in Urban Environment. Case Studies from Saint Petersburg, Russia

2020 ◽  
Vol 9 (1) ◽  
pp. 36
Author(s):  
Katerina V. Sazanova (nee Barinova) ◽  
Marina S. Zelenskaya ◽  
Vera V. Manurtdinova ◽  
Alina R. Izatulina ◽  
Aleksei V. Rusakov ◽  
...  
Keyword(s):  
Microbial Community ◽  
Optical Microscopy ◽  
Elemental Composition ◽  
Urban Environment ◽  
Microbial Metabolites ◽  
Stone Surface ◽  
Saint Petersburg ◽  
Icp Ms ◽  
Living Organisms ◽  
Selective Accumulation

The pattern of elements accumulation in biodeposits formed by living organisms and extracellular products of their metabolism (biofouling, primary soils) on different bedrocks (of the monuments of Historical necropoleis in Saint Petersburg) were studied by a complex of biological and mineralogical methods (optical microscopy, SEM, EDX, XRD, ICP MS, XRFS). The content of 46 elements in biodeposits with various communities of microorganisms is determined. The model recreating the picture of the input and selective accumulation of elements in biodeposits on the stone surface in outdoor conditions is assumed. It is shown that the main contribution to the elemental composition of biodeposits is made by the environment and the composition of the microbial community. The contribution of leaching under the action of microbial metabolites of mineral grains, entering biodeposits from the environment, is significantly greater than that of the underlying rock.

scholarly journals Mercury determination and speciation analysis in surface waters

2012 ◽  
Vol 10 (4) ◽  
pp. 1175-1182 ◽  
Author(s):  
Elisaveta Mladenova ◽  
Ivanka Dakova ◽  
Dimiter Tsalev ◽  
Irina Karadjova
Keyword(s):  
Surface Waters ◽  
Inductively Coupled Plasma ◽  
Mechanical Stability ◽  
Solid Phase ◽  
Chemical Vapor ◽  
Speciation Analysis ◽  
Regeneration Ability ◽  
Mercury Species ◽  
Icp Ms ◽  
Relative Standard

AbstractA sorbent L-cysteine grafted silica gel has been evaluated for separation and enrichment of dissolved inorganic i-Hg(II) and methylmercury CH3Hg(I) from surface waters at sub-µg L−1 concentrations. Chemical parameters for mercury species enrichment and separation have been optimized. Analytical schemes for the determination of Hg species, using selective column solid phase extraction (SPE) with continuous flow chemical vapor generation atomic absorption spectrometry (CF-CVG-AAS) or inductively coupled plasma-mass spectrometry (ICP-MS) were developed. Possibilities for on-site SPE enrichment were demonstrated as well. The limits of quantification were 1.5 and 5 ng L−1 for dissolved i-Hg(II) and CH3Hg(I) by CF-CVG-AAS and 1 and 2.5 ng L−1 by ICP-MS with relative standard deviations between 7–12% and 7–14%, respectively. The chemically modified SPE sorbent has demonstrated high regeneration ability, chemical and mechanical stability, acceptable capacity and good enrichment factors. Results for total dissolved mercury were in reasonable agreement with those from independent analyses by direct ICP-MS determinations for river waters and for estuarine water certified reference material.

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