scholarly journals Determination of biodegradation rate of carrier for microorganism immobilization fabricated based on starch

2013 ◽  
Vol 15 (3) ◽  
pp. 110-114 ◽  
Author(s):  
Ewa Tomaszewska-Ciosk ◽  
Antoni Golachowski ◽  
Ewa Zdybel
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Potato Starch ◽  
Water Environment ◽  
Storage Conditions ◽  
Yeast Cells ◽  
Biodegradation Rate ◽  
Heavy Soil ◽  
Microorganism Immobilization ◽  
Immobilized Microorganisms

Abstract The study was aimed on the determination of biodegradation rate of extruded starch carriers, with or without immobilized microorganisms in diversified storage conditions. The research was conducted on potato starch, in which Saccharomyces cerevisiae yeast cells were immobilized. Preparations with and without yeasts were than placed for 84 days in the environments of: light soil, heavy soil, compost, water and activated sludge. After 0, 7, 14, 21, 49 and 84 days of storage the preparations were perfused with water and analyzed. In the recovered samples the following tests were carried out: the force causing fracture, the elongation caused by the mentioned force, the mass and the diameter of the carrier. Due to the degradation the size and the mechanical properties of the samples were decreased. The rate of the degradation was strongly dependent on the environment of the storage. The fastest degradation of the carriers were observed for compost and heavy soil, while the slowest biodegradation was observed for the samples placed in the water environment. The rate of biodegradation was also influenced by the Saccharomyces cerevisiae yeasts. The rate of biodegradation was faster in the samples containing yeast cells, than in the extrudates without the microorganisms.

Identification of regulatory regions within the Ty1 transposable element that regulate iso-2-cytochrome c production in the CYC7-H2 yeast mutant

1984 ◽  
Vol 4 (7) ◽  
pp. 1393-1401
Author(s):  
B Errede ◽  
T S Cardillo ◽  
M A Teague ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Transposable Element ◽  
Yeast Cells ◽  
Yeast Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
Specific Restriction ◽  
Restriction Endonuclease Cleavage

The CYC7-H2 mutation in the yeast Saccharomyces cerevisiae was caused by insertion of a Ty1 transposable element in front of the iso-2-cytochrome c structural gene, CYC7. The Ty1 insertion places iso-2-cytochrome c production under control of regulatory signals that are normally required for mating functions in yeast cells. We have investigated the regions of the Ty1 insertion that are responsible for the aberrant production of iso-2-cytochrome c in the CYC7-H2 mutant. Five alterations of the CYC7-H2 gene were obtained by specific restriction endonuclease cleavage of the cloned DNA and ligation of appropriate fragments. The CYC7+, CYC7-H2, and modified CYC7-H2 genes were each inserted into the yeast vector YIp5 and used to transform a cytochrome c-deficient yeast strain. Expression and regulation of each allele integrated at the CYC7 locus have been compared in vivo by determination of the amount of iso-2-cytochrome c produced. These results show that distal regions of the Ty1 element are not essential for the CYC7-H2 overproducing phenotype. In contrast, alterations in the vicinity of the proximal Ty1 junction abolish the CYC7-H2 expression and give rise to different phenotypes.

scholarly journals Identification of regulatory regions within the Ty1 transposable element that regulate iso-2-cytochrome c production in the CYC7-H2 yeast mutant.

1984 ◽  
Vol 4 (7) ◽  
pp. 1393-1401 ◽  
Author(s):  
B Errede ◽  
T S Cardillo ◽  
M A Teague ◽  
F Sherman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cytochrome C ◽  
Transposable Element ◽  
Yeast Cells ◽  
Yeast Mutant ◽  
Yeast Saccharomyces Cerevisiae ◽  
Specific Restriction ◽  
Restriction Endonuclease Cleavage

The CYC7-H2 mutation in the yeast Saccharomyces cerevisiae was caused by insertion of a Ty1 transposable element in front of the iso-2-cytochrome c structural gene, CYC7. The Ty1 insertion places iso-2-cytochrome c production under control of regulatory signals that are normally required for mating functions in yeast cells. We have investigated the regions of the Ty1 insertion that are responsible for the aberrant production of iso-2-cytochrome c in the CYC7-H2 mutant. Five alterations of the CYC7-H2 gene were obtained by specific restriction endonuclease cleavage of the cloned DNA and ligation of appropriate fragments. The CYC7+, CYC7-H2, and modified CYC7-H2 genes were each inserted into the yeast vector YIp5 and used to transform a cytochrome c-deficient yeast strain. Expression and regulation of each allele integrated at the CYC7 locus have been compared in vivo by determination of the amount of iso-2-cytochrome c produced. These results show that distal regions of the Ty1 element are not essential for the CYC7-H2 overproducing phenotype. In contrast, alterations in the vicinity of the proximal Ty1 junction abolish the CYC7-H2 expression and give rise to different phenotypes.

scholarly journals Synthesis of Isomaltooligosaccharides (IMOs) from Sweet Potato Starch by Simultaneous Saccharification and Transglycosylation Using Saccharomyces cerevisiae Var. diastaticus BE 134 to Improve Purity of IMOs

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Quan Duong Hong ◽  
Tri Hoang Minh ◽  
Hong Gam Nguyen Thi ◽  
Thu Hien Nguyen Thi ◽  
Ngoc Hoa Nguyen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Reaction Time ◽  
Sweet Potato ◽  
Potato Starch ◽  
Yeast Cells ◽  
Synthesis Process ◽  
Reaction Parameters ◽  
Solution Ph ◽  
Sweet Potato Starch ◽  
Simultaneous Saccharification

This study developed a simple two-step procedure to produce isomaltooligosaccharides (IMOs) from low-cost sweet potato starch (SPS). Effect of various reaction parameters on the steps of the synthesis process of IMOs was systematically investigated. The results show that Spezyme Xtra enzyme was the most suitable for the liquefaction step. The oligosaccharide components’ contents, including G1–G10 and G2–G6, reached 73.95 ± 0.02% and 49.24 ± 3.19%, respectively, after liquefaction. The simultaneous saccharification and transglycosylation (SST) reaction of SPS followed the liquefaction after the α-amylase activity was deactivated. This reaction was simultaneously treated by β-amylase, pullulanase, and α-transglucosidase. The effect of various reaction parameters, consisting of solution pH, reaction temperature, enzyme dosage, and reaction time, on the SST reaction to synthesize IMOs from SPS was fully studied. The results showed that the highest concentration of IMOs (IG234) reached 68.85 ± 1.82 g/L at the optimal condition. The purification of pristine IMO was performed by adding Saccharomyces cerevisiae var. diastaticus BE 134 yeast cells at the final step of the procedure. In particular, the SST reaction for the synthesis of IMOs from SPS shortened SST reaction time by three times compared with other three-step synthesis procedures of IMOs. These findings show that the SPS-derived IMOs can be applied as a novel and inexpensive prebiotic healthcare product for human gastrointestinal health, dieters, and diabetics.

Yeast Cells Allow High-Level Expression and Formation of Polyomavirus-Like Particles

1999 ◽  
Vol 380 (3) ◽  
pp. 381-386 ◽  
Author(s):  
K. Sasnauskas ◽  
O. Buzaite ◽  
F. Vogel ◽  
B. Jandrig ◽  
R. Razanskas ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Expression System ◽  
Yeast Cells ◽  
Human Polyomavirus ◽  
Yeast Expression System ◽  
E Coli ◽  
Human Use ◽  
Capsid Protein Vp1 ◽  
High Level

AbstractPolyomavirus-derived virus-like particles (VLPs) have been described as potential carriers for encapsidation of nucleic acids in gene therapy. Although VLPs can be generated inE. colior insect cells, the yeast expression system should be advantageous as it is well established for the biotechnological generation of products for human use, especially because they are free of toxins hazardous for humans. We selected the yeastSaccharomyces cerevisiaefor expression of the major capsid protein VP1 of a non-human polyomavirus, the hamster polyomavirus (HaPV). Two entire HaPV VP1- coding sequences, starting with the authentic and a second upstream ATG, respectively, were subcloned and expressed to high levels inSaccharomyces cerevisiae. The expressed VP1 assembled spontaneously into VLPs with a structure resembling that of the native HaPV capsid. Determination of the subcellular localization revealed a nuclear localization of some particles formed by the N-terminally extended VP1, whereas particles formed by the authentic VP1 were found mainly in the cytoplasmic compartment.

scholarly journals Eukaryotic translation factor eIF5A contributes to acetic acid tolerance in Saccharomyces cerevisiae via transcriptional factor Ume6p

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Yanfei Cheng ◽  
Hui Zhu ◽  
Zhengda Du ◽  
Xuena Guo ◽  
Chenyao Zhou ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Acetic Acid ◽  
Adaptive Response ◽  
Acid Tolerance ◽  
Peptide Bond ◽  
Transcriptional Factor ◽  
Yeast Cells ◽  
Acetic Acid Tolerance ◽  
Translation Factor ◽  
Industrial Strains

Abstract Background Saccharomyces cerevisiae is well-known as an ideal model system for basic research and important industrial microorganism for biotechnological applications. Acetic acid is an important growth inhibitor that has deleterious effects on both the growth and fermentation performance of yeast cells. Comprehensive understanding of the mechanisms underlying S. cerevisiae adaptive response to acetic acid is always a focus and indispensable for development of robust industrial strains. eIF5A is a specific translation factor that is especially required for the formation of peptide bond between certain residues including proline regarded as poor substrates for slow peptide bond formation. Decrease of eIF5A activity resulted in temperature-sensitive phenotype of yeast, while up-regulation of eIF5A protected transgenic Arabidopsis against high temperature, oxidative or osmotic stress. However, the exact roles and functional mechanisms of eIF5A in stress response are as yet largely unknown. Results In this research, we compared cell growth between the eIF5A overexpressing and the control S. cerevisiae strains under various stressed conditions. Improvement of acetic acid tolerance by enhanced eIF5A activity was observed all in spot assay, growth profiles and survival assay. eIF5A prompts the synthesis of Ume6p, a pleiotropic transcriptional factor containing polyproline motifs, mainly in a translational related way. As a consequence, BEM4, BUD21 and IME4, the direct targets of Ume6p, were up-regulated in eIF5A overexpressing strain, especially under acetic acid stress. Overexpression of UME6 results in similar profiles of cell growth and target genes transcription to eIF5A overexpression, confirming the role of Ume6p and its association between eIF5A and acetic acid tolerance. Conclusion Translation factor eIF5A protects yeast cells against acetic acid challenge by the eIF5A-Ume6p-Bud21p/Ime4p/Bem4p axles, which provides new insights into the molecular mechanisms underlying the adaptive response and tolerance to acetic acid in S. cerevisiae and novel targets for construction of robust industrial strains.

scholarly journals Screening and Genetic Network Analysis of Genes Involved in Freezing and Thawing Resistance in DaMDHAR—Expressing Saccharomyces cerevisiae Using Gene Expression Profiling

Genes ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 219
Author(s):  
Il-Sup Kim ◽  
Woong Choi ◽  
Jonghyeon Son ◽  
Jun Hyuck Lee ◽  
Hyoungseok Lee ◽  
...  
Keyword(s):  
Gene Expression ◽  
Saccharomyces Cerevisiae ◽  
Transcription Factors ◽  
Stress Tolerance ◽  
Genetic Network ◽  
Yeast Cells ◽  
Enzymatic Antioxidants ◽  
Freezing And Thawing ◽  
Metal Ion Homeostasis ◽  
Transgenic Yeast

The cryoprotection of cell activity is a key determinant in frozen-dough technology. Although several factors that contribute to freezing tolerance have been reported, the mechanism underlying the manner in which yeast cells respond to freezing and thawing (FT) stress is not well established. Therefore, the present study demonstrated the relationship between DaMDHAR encoding monodehydroascorbate reductase from Antarctic hairgrass Deschampsia antarctica and stress tolerance to repeated FT cycles (FT2) in transgenic yeast Saccharomyces cerevisiae. DaMDHAR-expressing yeast (DM) cells identified by immunoblotting analysis showed high tolerance to FT stress conditions, thereby causing lower damage for yeast cells than wild-type (WT) cells with empty vector alone. To detect FT2 tolerance-associated genes, 3′-quant RNA sequencing was employed using mRNA isolated from DM and WT cells exposed to FT (FT2) conditions. Approximately 332 genes showed ≥2-fold changes in DM cells and were classified into various groups according to their gene expression. The expressions of the changed genes were further confirmed using western blot analysis and biochemical assay. The upregulated expression of 197 genes was associated with pentose phosphate pathway, NADP metabolic process, metal ion homeostasis, sulfate assimilation, β-alanine metabolism, glycerol synthesis, and integral component of mitochondrial and plasma membrane (PM) in DM cells under FT2 stress, whereas the expression of the remaining 135 genes was partially related to protein processing, selenocompound metabolism, cell cycle arrest, oxidative phosphorylation, and α-glucoside transport under the same condition. With regard to transcription factors in DM cells, MSN4 and CIN5 were activated, but MSN2 and MGA1 were not. Regarding antioxidant systems and protein kinases in DM cells under FT stress, CTT1, GTO, GEX1, and YOL024W were upregulated, whereas AIF1, COX2, and TRX3 were not. Gene activation represented by transcription factors and enzymatic antioxidants appears to be associated with FT2-stress tolerance in transgenic yeast cells. RCK1, MET14, and SIP18, but not YPK2, have been known to be involved in the protein kinase-mediated signalling pathway and glycogen synthesis. Moreover, SPI18 and HSP12 encoding hydrophilin in the PM were detected. Therefore, it was concluded that the genetic network via the change of gene expression levels of multiple genes contributing to the stabilization and functionality of the mitochondria and PM, not of a single gene, might be the crucial determinant for FT tolerance in DaMDAHR-expressing transgenic yeast. These findings provide a foundation for elucidating the DaMDHAR-dependent molecular mechanism of the complex functional resistance in the cellular response to FT stress.

scholarly journals Pulsed Electric Field (PEF) Enhances Iron Uptake by the Yeast Saccharomyces cerevisiae

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 850
Author(s):  
Karolina Nowosad ◽  
Monika Sujka ◽  
Urszula Pankiewicz ◽  
Damijan Miklavčič ◽  
Marta Arczewska
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electric Field ◽  
Metal Ion ◽  
Treatment Time ◽  
Control Sample ◽  
Pulsed Electric Field ◽  
Yeast Cells ◽  
Iron Ions ◽  
Metal Ion Binding ◽  
Yeast Saccharomyces Cerevisiae

The aim of the study was to investigate the influence of a pulsed electric field (PEF) on the level of iron ion accumulation in Saccharomyces cerevisiae cells and to select PEF conditions optimal for the highest uptake of this element. Iron ions were accumulated most efficiently when their source was iron (III) nitrate. When the following conditions of PEF treatment were used: voltage 1500 V, pulse width 10 μs, treatment time 20 min, and a number of pulses 1200, accumulation of iron ions in the cells from a 20 h-culture reached a maximum value of 48.01 mg/g dry mass. Application of the optimal PEF conditions thus increased iron accumulation in cells by 157% as compared to the sample enriched with iron without PEF. The second derivative of the FTIR spectra of iron-loaded and -unloaded yeast cells allowed us to determine the functional groups which may be involved in metal ion binding. The exposure of cells to PEF treatment only slightly influenced the biomass and cell viability. However, iron-enriched yeast (both with or without PEF) showed lower fermentative activity than a control sample. Thus obtained yeast biomass containing a high amount of incorporated iron may serve as an alternative to pharmacological supplementation in the state of iron deficiency.

scholarly journals Expression of an ATP-binding cassette transporter-encoding gene (YOR1) is required for oligomycin resistance in Saccharomyces cerevisiae.

1995 ◽  
Vol 15 (12) ◽  
pp. 6875-6883 ◽  
Author(s):  
D J Katzmann ◽  
T C Hallstrom ◽  
M Voet ◽  
W Wysock ◽  
J Golin ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fusion Gene ◽  
Sequence Similarity ◽  
Yeast Cells ◽  
Atp Binding ◽  
Zinc Cluster ◽  
Atp Binding Cassette Transporter ◽  
Transporter Family ◽  
Encoding Gene ◽  
Atp Binding Cassette

Semidominant mutations in the PDR1 or PDR3 gene lead to elevated resistance to cycloheximide and oligomycin. PDR1 and PDR3 have been demonstrated to encode zinc cluster transcription factors. Cycloheximide resistance mediated by PDR1 and PDR3 requires the presence of the PDR5 membrane transporter-encoding gene. However, PDR5 is not required for oligomycin resistance. Here, we isolated a gene that is necessary for PDR1- and PDR3-mediated oligomycin resistance. This locus, designated YOR1, causes a dramatic elevation in oligomycin resistance when present in multiple copies. A yor1 strain exhibits oligomycin hypersensitivity relative to an isogenic wild-type strain. In addition, loss of the YOR1 gene blocks the elevation in oligomycin resistance normally conferred by mutant forms of PDR1 or PDR3. The YOR1 gene product is predicted to be a member of the ATP-binding cassette transporter family of membrane proteins. Computer alignment indicates that Yor1p shows striking sequence similarity with multidrug resistance-associated protein, Saccharomyces cerevisiae Ycf1p, and the cystic fibrosis transmembrane conductance regulator. Use of a YOR1-lacZ fusion gene indicates that YOR1 expression is responsive to PDR1 and PDR3. While PDR5 expression is strictly dependent on the presence of PDR1 or PDR3, control of YOR1 expression has a significant PDR1/PDR3-independent component. Taken together, these data indicate that YOR1 provides the link between transcriptional regulation by PDR1 and PDR3 and oligomycin resistance of yeast cells.

Effect of Different Storage Conditions on Soybean Oil Acid Value

2014 ◽  
Vol 962-965 ◽  
pp. 1235-1238
Author(s):  
Mei Mei Hao ◽  
Xi Hong Li ◽  
Hai Dong Liu ◽  
Wei Qiao Yang ◽  
Chong Xiao Shao ◽  
...  
Keyword(s):  
Moisture Content ◽  
Soybean Oil ◽  
Acid Value ◽  
Storage Condition ◽  
Storage Conditions

Under the condition of nine kinds of storage, In this thesis, through the determination of acid value of soybean oil, to search for the best storage condition, used to prevent the soybean oil acid value rise, through the analysis of the acid value data, We find the best storage condition, is 0°C, 6% moisture content, and PVC plastic wrap packaging.

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