The induction of cytoplasmic petite mutants of Saccharomyces cerevisiae by hydrostatic pressure

1977 ◽  
Vol 26 (1) ◽  
pp. 373-385
Author(s):  
M.P. Rosin ◽  
A.M. Zimmerman
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrostatic Pressure ◽  
Cell Survival ◽  
Growth Stage ◽  
Lag Phase ◽  
Pressure Treatment ◽  
Tetrad Analysis ◽  
Petite Mutants ◽  
Wide Range ◽  
Inductive Agent

This study demonstrates that hydrostatic pressure is a potent inductive agent of the petite mutation in cultures of Saccharomyces cerevisiae. The inductive capacity of this mutagen is dependent on the magnitude and the duration of the pressure treatment. Furthermore, the extent of petite induction varies with the growth stage of the culture. Induction occurs in pressure-treated (1-4 X 1-(4) lbf in.-2 or 9–66 X 10(4) kN m-2 for 4 h) log growth cultures but not in stationary or lag phase cultures. Petite induction and cell survival are also dependent on the particular strain of yeast which is pressure-treated. Tetrad analysis and complementation assays demonstrate that pressure-induced petite cells are cytoplasmic in nature. Moreover, induced petite cells show a wide range of suppressivity (2–99%) with a large proportion of the petite cells being highly suppressive.

High-hydrostatic-pressure treatment impairs actin cables and budding in Saccharomyces cerevisiae

2006 ◽  
Vol 101 (6) ◽  
pp. 515-518 ◽  
Author(s):  
Taketo Kawarai ◽  
Seisuke Arai ◽  
Soichi Furukawa ◽  
Hirokazu Ogihara ◽  
Makari Yamasaki
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Hydrostatic Pressure ◽  
High Hydrostatic Pressure ◽  
Pressure Treatment ◽  
High Hydrostatic Pressure Treatment ◽  
Actin Cables

The Effect of Growth Stage and Growth Temperature on High Hydrostatic Pressure Inactivation of Some Psychrotrophic Bacteria in Milk

2001 ◽  
Vol 64 (4) ◽  
pp. 514-522 ◽  
Author(s):  
J. M. J. McCLEMENTS ◽  
M. F. PATTERSON ◽  
M. LINTON
Keyword(s):  
Hydrostatic Pressure ◽  
Stationary Phase ◽  
Growth Temperature ◽  
High Hydrostatic Pressure ◽  
Growth Stage ◽  
Growth Stages ◽  
Pressure Treatment ◽  
Psychrotrophic Bacteria ◽  
Pressure Injury ◽  
Pressure Resistance

The effect of high hydrostatic pressure on the survival of the psychrotrophic organisms Listeria monocytogenes, Bacillus cereus, and Pseudomonas fluorescens was investigated in ultrahigh-temperature milk. Variation in pressure resistance between two strains of each organism were studied. The effect of growth stage (exponential and stationary phase), growth temperature (8 and 30°C) on pressure resistance, and sublethal pressure injury were investigated. Exponential-phase cells were significantly less resistant to pressure than stationary-phase cells for all of the three species studied (P < 0.05). Growth temperature was found to have a significant effect at the two growth stages studied. Exponential cells grown at 8°C were more resistant than those grown at 30°C, but for stationary-phase cells the reverse was true. B. cereus stationary-phase cells grown at 30°C were the most pressure resistant studied. L. monocytogenes showed the most sublethal damage compared to B. cereus and P. fluorescens. B. cereus spores were more resistant to pressure than vegetative cells. Pressure treatment at 400 MPa for 25 min at 30°C gave a 0.45-log inactivation. Pressure treatment at 8°C induced significantly less spore germination than at 30°C. This study indicates the importance of the history of a bacterial culture prior to pressure treatment and that bacterial spores require more severe pressure treatments, probably in combination with other preservation techniques, to ensure inactivation.

scholarly journals Reciprocal hemizygosity analysis reveals that the Saccharomyces cerevisiae CGI121 gene affects lag time duration in synthetic grape must

2021 ◽  
Author(s):  
Runze Li ◽  
Rebecca C Deed
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Low Temperatures ◽  
Lag Time ◽  
Lag Phase ◽  
Phenotypic Traits ◽  
Time Duration ◽  
Phase Duration ◽  
Grape Must ◽  
The Impact ◽  
Reciprocal Hemizygosity Analysis

Abstract It is standard practice to ferment white wines at low temperatures (10-18 °C). However, low temperatures increase fermentation duration and risk of problem ferments, leading to significant costs. The lag duration at fermentation initiation is heavily impacted by temperature; therefore, identification of Saccharomyces cerevisiae genes influencing fermentation kinetics is of interest for winemaking. We selected 28 S. cerevisiae BY4743 single deletants, from a prior list of open reading frames (ORFs) mapped to quantitative trait loci (QTLs) on chromosomes VII and XIII, influencing the duration of fermentative lag time. Five BY4743 deletants, Δapt1, Δcgi121, Δclb6, Δrps17a, and Δvma21, differed significantly in their fermentative lag duration compared to BY4743 in synthetic grape must (SGM) at 15 °C, over 72 h. Fermentation at 12.5 °C for 528 h confirmed the longer lag times of BY4743 Δcgi121, Δrps17a, and Δvma21. These three candidate ORFs were deleted in S. cerevisiae RM11-1a and S288C to perform single reciprocal hemizygosity analysis (RHA). RHA hybrids and single deletants of RM11-1a and S288C were fermented at 12.5 °C in SGM and lag time measurements confirmed that the S288C allele of CGI121 on chromosome XIII, encoding a component of the EKC/KEOPS complex, increased fermentative lag phase duration. Nucleotide sequences of RM11-1a and S288C CGI121 alleles differed by only one synonymous nucleotide, suggesting that intron splicing, codon bias, or positional effects might be responsible for the impact on lag phase duration. This research demonstrates a new role of CGI121 and highlights the applicability of QTL analysis for investigating complex phenotypic traits in yeast.

scholarly journals Crossover Interference in Saccharomyces cerevisiae Requires a TID1/RDH54- and DMC1-Dependent Pathway

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1273-1286 ◽  
Author(s):  
Miki Shinohara ◽  
Kazuko Sakai ◽  
Akira Shinohara ◽  
Douglas K Bishop
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Meiotic Recombination ◽  
Strand Break ◽  
Tetrad Analysis ◽  
Yeast Saccharomyces Cerevisiae ◽  
Crossover Interference ◽  
Meiotic Progression ◽  
Invasion Stage ◽  
Strand Invasion ◽  
Dependent Pathway

Abstract Two RecA-like recombinases, Rad51 and Dmc1, function together during double-strand break (DSB)-mediated meiotic recombination to promote homologous strand invasion in the budding yeast Saccharomyces cerevisiae. Two partially redundant proteins, Rad54 and Tid1/Rdh54, act as recombinase accessory factors. Here, tetrad analysis shows that mutants lacking Tid1 form four-viable-spore tetrads with levels of interhomolog crossover (CO) and noncrossover recombination similar to, or slightly greater than, those in wild type. Importantly, tid1 mutants show a marked defect in crossover interference, a mechanism that distributes crossover events nonrandomly along chromosomes during meiosis. Previous work showed that dmc1Δ mutants are strongly defective in strand invasion and meiotic progression and that these defects can be partially suppressed by increasing the copy number of RAD54. Tetrad analysis is used to show that meiotic recombination in RAD54-suppressed dmc1Δ cells is similar to that in tid1; the frequency of COs and gene conversions is near normal, but crossover interference is defective. These results support the proposal that crossover interference acts at the strand invasion stage of recombination.

scholarly journals A genome-scale metabolic model of Saccharomyces cerevisiae that integrates expression constraints and reaction thermodynamics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Omid Oftadeh ◽  
Pierre Salvy ◽  
Maria Masid ◽  
Maxime Curvat ◽  
Ljubisa Miskovic ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Expression System ◽  
Biomass Composition ◽  
Industrial Biotechnology ◽  
Overflow Metabolism ◽  
Cellular Expression ◽  
A Genome ◽  
Wide Range ◽  
Eukaryotic Organisms ◽  
Genome Scale

AbstractEukaryotic organisms play an important role in industrial biotechnology, from the production of fuels and commodity chemicals to therapeutic proteins. To optimize these industrial systems, a mathematical approach can be used to integrate the description of multiple biological networks into a single model for cell analysis and engineering. One of the most accurate models of biological systems include Expression and Thermodynamics FLux (ETFL), which efficiently integrates RNA and protein synthesis with traditional genome-scale metabolic models. However, ETFL is so far only applicable for E. coli. To adapt this model for Saccharomyces cerevisiae, we developed yETFL, in which we augmented the original formulation with additional considerations for biomass composition, the compartmentalized cellular expression system, and the energetic costs of biological processes. We demonstrated the ability of yETFL to predict maximum growth rate, essential genes, and the phenotype of overflow metabolism. We envision that the presented formulation can be extended to a wide range of eukaryotic organisms to the benefit of academic and industrial research.

scholarly journals Engineering the Monomer Composition of Polyhydroxyalkanoates Synthesized in Saccharomyces cerevisiae

2006 ◽  
Vol 72 (1) ◽  
pp. 536-543 ◽  
Author(s):  
Bo Zhang ◽  
Ross Carlson ◽  
Friedrich Srienc
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Fatty Acid ◽  
Chain Length ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Pha Synthase ◽  
Fatty Acid Degradation ◽  
Medium Chain ◽  
Acid Degradation ◽  
Wide Range

ABSTRACT Polyhydroxyalkanoates (PHAs) have received considerable interest as renewable-resource-based, biodegradable, and biocompatible plastics with a wide range of potential applications. We have engineered the synthesis of PHA polymers composed of monomers ranging from 4 to 14 carbon atoms in either the cytosol or the peroxisome of Saccharomyces cerevisiae by harnessing intermediates of fatty acid metabolism. Cytosolic PHA production was supported by establishing in the cytosol critical β-oxidation chemistries which are found natively in peroxisomes. This platform was utilized to supply medium-chain (C6 to C14) PHA precursors from both fatty acid degradation and synthesis to a cytosolically expressed medium-chain-length (mcl) polymerase from Pseudomonas oleovorans. Synthesis of short-chain-length PHAs (scl-PHAs) was established in the peroxisome of a wild-type yeast strain by targeting the Ralstonia eutropha scl polymerase to the peroxisome. This strain, harboring a peroxisomally targeted scl-PHA synthase, accumulated PHA up to approximately 7% of its cell dry weight. These results indicate (i) that S. cerevisiae expressing a cytosolic mcl-PHA polymerase or a peroxisomal scl-PHA synthase can use the 3-hydroxyacyl coenzyme A intermediates from fatty acid metabolism to synthesize PHAs and (ii) that fatty acid degradation is also possible in the cytosol as β-oxidation might not be confined only to the peroxisomes. Polymers of even-numbered, odd-numbered, or a combination of even- and odd-numbered monomers can be controlled by feeding the appropriate substrates. This ability should permit the rational design and synthesis of polymers with desired material properties.

Local Hydrostatic Pressure Test for Cylindrical Vessels

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
H. Al-Gahtani ◽  
A. Khathlan ◽  
M. Sunar ◽  
M. Naffa'a
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Hydrostatic Pressure ◽  
Cylindrical Vessel ◽  
Geometrical Parameters ◽  
The Finite Element Method ◽  
Wide Range ◽  
Pressure Test ◽  
Local Test ◽  
Alternative Test

The juncture of a small cylindrical nozzle to a large cylindrical vessel is very common in the pressure vessel industry. Upon fabrication, it is required that the whole structure is subjected to pressure testing. The test can be expensive as it necessitates pressurizing the whole structure typically having a large volume. Hence, it is proposed to make a “local test,” which is considerably simpler as it involves capping the small nozzle and testing only a relatively small portion of the structure. This paper investigates the accuracy and reliability of such an alternative test, using the finite-element method. Two different finite-element types are used in the study, specifically a shell-based element and a solid-based element. The verification of the finite-element results for two different cases shows that the models used in the study are valid. It also proves that the two element types yield very similar stress results. In addition, the study includes a numerical investigation of more than 40 different nozzle-to-vessel junctures with a wide range of parameters for the nozzle and vessel. The results indicate that the use of cylindrical caps that are slightly larger than the nozzle is not recommended as it produces stresses that are significantly different from those for the original required pressure test. As such, the study provides an estimate of the smallest size of the cap that may be used in the local test to generate stresses that agree with the full test. For most practical geometries, it is shown that the size of the cap needs to be at least 2–30 times larger than that of the nozzle, depending on the geometrical parameters of the juncture.

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