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.

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 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.

A CONVENIENT METHOD OF OBTAINING ASCOSPORES FROM BAKERS' YEAST

1949 ◽  
Vol 27c (4) ◽  
pp. 179-189 ◽  
Author(s):  
A. M. Adams
Keyword(s):  
Convenient Method ◽  
Sodium Acetate ◽  
Solid Medium ◽  
Genetic Research ◽  
Yeast Cells ◽  
Sporulation Medium ◽  
Direct Transfer ◽  
Yeast Cultures ◽  
High Yields ◽  
Solid Nutrient Medium

The superiority of methods involving the use of sporulation media containing acetate, first introduced by Stantial and Elder, over several commonly employed methods is established. A new method for obtaining ascospores from bakers' yeast cultures is recommended involving the direct transfer of vegetative cells from a solid nutrient medium to a solid medium containing acetate. High yields of ascospores are consistently produced after seven days' incubation. This method should lend itself particularly to use in the preparation of ascospores for instructional work, and for genetic research in yeast, and may also find application in yeast taxonomy. The technique recommended is as follows: vegetative yeast cells are multiplied on tomato juice agar or on dextrose nutrient agar, and are then transferred to a solid sporulation medium containing 0.04% dextrose, 0.14% anhydrous sodium acetate, and 2% agar.

Differentiation of Yeast Cultures in Ruminant Feedingstuffs Using a Rapid DNA Fingerprinting Technique

1994 ◽  
Vol 1994 ◽  
pp. 101-101
Author(s):  
Elizabeth Moore ◽  
Denis R. Headon
Keyword(s):  
Sodium Dodecyl ◽  
Yeast Cells ◽  
Microbial Populations ◽  
Yeast Culture ◽  
Yeast Cultures ◽  
Yeast Strains ◽  
Genetic Sequences ◽  
Polymerase Chain ◽  
Different Strains ◽  
Triton X

Research indicates that certain yeast strains are beneficial in their capacity to stimulate key microbial populations. This stimulation is strain specific with similar yeast strains exerting their effect on totally different microbial populations. Future yeast culture supplements may contain mixtures of different strains designed to suit specific diets. This, therefore, requires the development of a rapid sensitive technique to differentiate among taxonomically similar yeast strains in animal diets. This technique, termed the Randomly Amplified Polymorphic DNA (RAPD) assay, is based upon the use of randomly designed short polynucleotide primers to amplify genetic sequences from the DNA of the desired yeast strain. Our objective involves the development of this technique to distinguish between closely related yeast strains present in feed. The feed sample investigated was a standard cattle ration containing three strains of Saccharomyces cerevisiae (1026, 2045 and 2020) and Candida utilis 3001 at a concentration of 106 CFU/g respectively. Isolation of single colonies of yeast strains present was achieved by feed extraction in dilution buffer followed by plating a series of dilutions on rose-bengal agar. Thirty randomly selected colonies were cultured in YPD (1% yeast extract, 2% peptone, 2% glucose) broth for 24 - 30 hours at 30°C. Genomic DNA was isolated from yeast cells by standard methods based on subjection of the cells to vortex mixing in the presence of glass beads, triton X-100, sodium dodecyl sulphate, phenol and chloroform. Isolated DNA from randomly selected colonies was amplified by Polymerase Chain Reaction (PCR) for 45 cycles of 1 min at 94°C, 1 min at 36°C and 1 min at 72°C using randomly designed 10 bp primers.

scholarly journals Glucose Signaling Pathway and Growth Conditions Regulate Gene Expression in Retrotransposon Ty2

2009 ◽  
Vol 64 (7-8) ◽  
pp. 526-532 ◽  
Author(s):  
Sezai Türkel ◽  
Özgür Bayram ◽  
Elif Arık
Keyword(s):  
Gene Expression ◽  
Growth Conditions ◽  
Glucose Sensors ◽  
Yeast Cells ◽  
Growth Stages ◽  
Regulate Gene Expression ◽  
Glucose Signaling ◽  
Yeast Cultures ◽  
Membrane Bound ◽  
High Level

Gene expression in the yeast retrotransposon Ty2 is regulated at transcriptional and translational levels. In this study, we have shown that the transcription of Ty2 is partially dependent on the membrane-bound glucose sensors Gpr1p and Mth1p in Saccharomyces cerevisiae. Transcription of Ty2 decreased approx. 3-fold in the gpr1, mth1 yeast mutant. Moreover, our results revealed that the transcription of Ty2 fluctuates during the growth stages of S. cerevisae. Both transcription and the frameshift rate of Ty2 rapidly dropped when the stationary stage yeast cells were inoculated into fresh medium. There was an instant activation of Ty2 transcription and a high level expression during the entire logarithmic stage of yeast growth. However, the transcription of Ty2 decreased 2-fold when the yeast cultures entered the stationary stage. The frameshift rate in Ty2 also varied depending on the growth conditions. The highest frameshift level was observed during the mid-logarithmic stage. It decreased up to 2-fold during the stationary stage. Furthermore, we have found that the frameshift rate of Ty2 diminished at least 5-fold in slowly growing yeasts. These results indicate that the transcription and the frameshift efficiency are coordinately regulated in the retrotransposon Ty2 depending on the growth conditions of S. cerevisiae.

scholarly journals MODIFICAÇÕES NO MEIO DE CULTURA, FOTOPERÍODO E TEMPO DE CULTIVO AFETAM O ALONGAMENTO E ENRAIZAMENTO IN VITRO DE BANANEIRA CV. PACOVAN

Nativa ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
Marcos Vinícius Marques Pinheiro ◽  
Ana Cristina Portugal Pinto De Carvalho ◽  
Fabrina Bolzan Martins
Keyword(s):  
Plant Height ◽  
Culture Medium ◽  
Culture Media ◽  
Dry Weight ◽  
Salt Mixture ◽  
Musa Spp ◽  
Fresh Biomass ◽  
Shoot Dry Weight ◽  
Number Of Leaves

No intuito de elevar as taxas de sobrevivência durante a etapa de aclimatização e posterior plantio a campo, avaliou-se o enraizamento in vitro de bananeira cv. Pacovan, em diferentes concentrações de sais MS e de sacarose. Utilizou-se DIC, esquema fatorial (6x2x3), com seis meios de cultura [sendo três concentrações de nutrientes do meio MS (100%; 50% de macronutrientes; e 50% dos sais macro e micronutrientes), e duas concentrações de sacarose (1,5/3,0%)], dois fotoperíodos (12/16 h) e três tempos de cultivo (21, 28 ou 35 dias) e seis repetições/tratamento. Analisaram-se: altura da planta, número de folhas/planta, massas frescas e secas das partes aérea e radicular. Para altura da planta, massa fresca da parte aérea e radicular, o meio MS 50% dos sais + sacarose (1,5%) com fotoperíodo de 16 h e tempo de cultivo de 35 dias foi satisfatório. Para massa seca da parte aérea foi MS 50% de sais + sacarose (3%), e para massa seca da parte radicular, MS 100% + sacarose (3%) (em 12hs/28 dias e 16hs/21 dias). Para o alongamento/enraizamento in vitro da bananeira cv. Pacovan sugere-se MS 50% de sais (macro e micronutrientes), redução ou manutenção de sacarose (1,5 ou 3%) em 16h/35 dias de cultivo.Palavra-chave: Musa spp., propagação in vitro, sistema radicular. CHANGES IN CULTURE MEDIUM, PHOTOPERIOD AND TIME OF CULTIVATION AFFECT THE IN VITRO ELONGATION AND ROOTING OF BANANA CV. PACOVAN ABSTRACT:In order to achieve high rates of survival during the acclimatization and later planting in the field, was evaluated the in vitro of banana cv. Pacovan plants under different concentrations of sucrose and MS basal salt mixture. The experiment was assembled in a DIC, in 6x2x3, six different culture media [three different MS salt mixture concentrations (100%; 50% of macronutrients; and 50% of macro/micronutrients) and two sucrose concentrations (1.5/3%)], two photoperiods (12/16 hours) and three cultivation times (21, 28 or 35 days). Each treatment was composed by 6 replicates. Plant height, number of leaves/plant, fresh and dry weight of roots and shoots, were analyzed. Satisfactory results for plant height and shoot and root fresh biomass were observed in MS with macro/micronutrients (50%) + sucrose (3%), 16 hours/35 days. The highest values of shoot dry weight were observed in MS with macro/micronutrients (50%) + sucrose (3%); the highest root dry weight was achieved with MS 100% + sucrose (3%) (12hs/28 and 16hs/21 days). The suggested medium for the in vitro elongation and rooting stage of banana cv. Pacovan is the MS with 50% of salts (macro and micronutrients), reduction or maintenance of sucrose (1.5 or 3%) in 16h/35 days of cultivation.Keywords: Musa spp., in vitro propagation, root system. DOI:

scholarly journals Preference of Proteomonas Sulcata Anion Channelrhodopsin for Nitrate Revealed Using a pH Electrode Method

2021 ◽  
Author(s):  
Chihiro Kikuchi ◽  
Hina Kurane ◽  
Takuma Watanabe ◽  
Makoto Demura ◽  
Takashi Kikukawa ◽  
...  
Keyword(s):  
Transmembrane Helix ◽  
Anion Transport ◽  
Yeast Cells ◽  
Ion Pump ◽  
Transport Activity ◽  
Electrode Method ◽  
Anion Transport Activity ◽  
Living Organisms ◽  
Stable Forms ◽  
Ph Electrode

Abstract Ion channel proteins are physiologically important molecules in living organisms. Their molecular functions have been investigated using electrophysiological methods, which enable quantitative, precise and advanced measurements and thus require complex instruments and experienced operators. For simpler and easier measurements, we measured the anion transport activity of light-gated anion channelrhodopsins (ACRs) using a pH electrode method, which has already been established for ion pump rhodopsins. Using that method, we successfully measured the anion transport activity and its dependence on the wavelength of light, i.e. its action spectra, and on the anion species, i.e. its selectivity or preference, of several ACRs expressed in yeast cells. In addition, we identified the strong anion transport activity and the preference for NO3- of an ACR from a marine cryptophyte algae Proteomonas sulcata, named PsuACR_353. Such a preference was discovered for the first time in microbial pump- or channel-type rhodopsins. Nitrate is one of the most stable forms of nitrogen and is used as a nitrogen source by most organisms including plants. Therefore, PsuACR_353 may play a role in NO3- transport and might take part in NO3--related cellular functions in nature. Measurements of a mutant protein revealed that a Thr residue in the 3rd transmembrane helix, which corresponds to Cys102 in GtACR1, contributed to the preference for NO3-. These findings will be helpful to understand the mechanisms of anion transport, selectivity and preference of PsuACR_353.

scholarly journals Threonine Overproduction in Yeast Strains Carrying theHOM3-R2 Mutant Allele under the Control of Different Inducible Promoters

1999 ◽  
Vol 65 (1) ◽  
pp. 110-116 ◽  
Author(s):  
María-José Farfán ◽  
Luis Aparicio ◽  
Isabel L. Calderón
Keyword(s):  
Mutant Allele ◽  
Metabolic Flux ◽  
Dry Weight ◽  
Yeast Cells ◽  
Aspartate Kinase ◽  
Inducible Promoters ◽  
Yeast Strains ◽  
Threonine Production ◽  
Amino Acid Contents ◽  
Serine Deaminase

ABSTRACT The HOM3 gene of Saccharomyces cerevisiaecodes for aspartate kinase, which plays a crucial role in the regulation of the metabolic flux that leads to threonine biosynthesis. With the aim of obtaining yeast strains able to overproduce threonine in a controlled way, we have placed the HOM3-R2 mutant allele, which causes expression of a feedback-insensitive enzyme, under the control of four distinctive regulatable yeast promoters, namely, P GAL1 , P CHA1 , P CYC1-HSE2 , and P GPH1 . The amino acid contents of strains bearing the different constructs were analyzed both under repression and induction conditions. Although some differences in overall threonine production were found, a maximum of around 400 nmol/mg (dry weight) was observed. Other factors, such as excretion to the medium and activity of the catabolic threonine/serine deaminase, also affect threonine accumulation. Thus, improvement of threonine productivity by yeast cells would probably require manipulation of these and other factors.

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