scholarly journals Proton stoichiometry of the overexpressed uracil symport of the yeast Saccharomyces cerevisiae

1998 ◽  
Vol 336 (1) ◽  
pp. 125-130 ◽  
Author(s):  
A. Alan EDDY ◽  
Pamela HOPKINS
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Time Course ◽  
Average Rate ◽  
Linear Phase ◽  
Total Rate ◽  
Time Intervals ◽  
Yeast Saccharomyces Cerevisiae ◽  
Basal Rate ◽  
Proton Uptake ◽  
The Mean

Information about the molecular biology of the uracil carrier of Saccharomyces cerevisiae is now available but its properties as a symport are unexplored. We have now studied its proton stoichiometry at pH 6.5, 4.8 and 4.2, in a yeast strain overexpressing the symport and unable to metabolize uracil. After the depletion of cellular ATP, uracil uptake followed an approximately exponential time course to reach a plateau. Proton uptake was then indistinguishable from the basal rate shown in controls without added uracil. It was concluded that more than 87% of the uracil flux through the system was coupled to symported protons. Because the basal rate was a significant fraction of the total rate of proton uptake at pH 4.2 or 4.8, the ratio of the proton and uracil flows could not be defined uniquely during the initial near-linear phase of uptake. However, the average rate of proton uptake during increasing time intervals up to 120 s was shown to be a linear function of the corresponding average rate of uracil uptake. This relationship, defining approx. 90% of the eventual uracil uptake, was used to deduce the mean proton stoichiometry as approx. 3 at pH 4.2, falling to near 2 at pH 6.5. The rate of uracil uptake increased 4-fold when the negative proton gradient (ΔµH) acting across the plasma membrane increased from 60 to 200 mV. The rate fell markedly after depolarization by KCl. The maximum uracil gradient (ΔµS) was less affected by depolarization. The ratio ΔµS/ΔµH fell from approx. 2 to near 1 as ΔµH increased in the above range. In contrast with the starved yeast, uracil accumulation during energy metabolism followed a pump-leak model.

Biosurfactant production and its effects on solubilization activity of phenanthrene: a longitudinal study

2016 ◽  
Vol 74 (3) ◽  
pp. 580-585
Author(s):  
Masoumeh Golshan ◽  
Maryam Dastoorpour ◽  
Roshanak Rezaei Kalantary
Keyword(s):  
Time Course ◽  
Inoculum Size ◽  
Biosurfactant Production ◽  
Practical Application ◽  
Time Intervals ◽  
Initial Inoculum ◽  
Bacterial Inoculum ◽  
Polycyclic Aromatic ◽  
The Mean ◽  
Time Course Study

Pseudomonas facilis and Pseudomonasspp., isolated on the basis of its ability to grow on polycyclic aromatic hydrocarbon, was assayed for biosurfactant production (BP) potentials by measuring the surface tension (ST) of the culture supernatant at different time intervals. The strains in three levels of initial inoculum size (OD600 nm = 0.5, 1, 1.5) were added to medium to determine if bacterial inoculum size affects solubilization of phenanthrene (PHE).The result showed that although the two strains reduced the mean ST to less than 34.12 mN m−1 at the end of day 6, mean solubilization activity of PHE reached 77.05 mg L−1 on the sixth day. There was a significant increase in BP over time (P = 0.008); reaching its peak, 157.84 mg L−1, at the end of the sixth day. Mean solubilization activity of PHE was not significantly different for the two strains (P = 0.216). The time-course study revealed that the ST reduction and BP potential was enhanced as inoculation size increased, leading to higher PHE solubility during the incubation time. However, the trend of increase in PHE solubility was not totally in the same way to cell growth and BP. It may be suggested that more bacterial density needs to be inoculated for practical application of effective bioremediation.

scholarly journals A glimpse of potential transposable element impact on adaptation of the industrial yeast Saccharomyces cerevisiae

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Z Lewis Liu ◽  
Xiaoqiu Huang
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Transposable Element ◽  
Time Course ◽  
Lag Phase ◽  
Industrial Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Inhibitory Compounds ◽  
Phase Sequence ◽  
Time Course Study ◽  
Copy Number Changes

ABSTRACT The adapted industrial yeast strain Saccharomyces cerevisiae NRRL Y-50049 is able to in situ detoxify major toxic aldehyde compounds derived from sugar conversion of lignocellulosic biomass while producing ethanol. Pathway-based studies on its mechanisms of tolerance have been reported previously, however, little is known about transposable element (TE) involvement in its adaptation to inhibitory compounds. This work presents a comparative dynamic transcription expression analysis in response to a toxic treatment between Y-50049 and its progenitor, an industrial type strain NRRL Y-12632, using a time-course study. At least 77 TEs from Y-50049 showed significantly increased expression compared with its progenitor, especially during the late lag phase. Sequence analysis revealed significant differences in TE sequences between the two strains. Y-50049 was also found to have a transposons of yeast 2 (Ty2) long terminal repeat-linked YAT1 gene showing significantly higher copy number changes than its progenitor. These results raise awareness of potential TE involvement in the adaptation of industrial yeast to the tolerance of toxic chemicals.

scholarly journals A cytofluorimetric analysis of a Saccharomyces cerevisiae population cultured in a fed-batch bioreactor

2021 ◽  
Author(s):  
Massimo Sanchez ◽  
Emanuela Palomba ◽  
Valentina Tirelli ◽  
Elisabetta de Alteriis ◽  
Carmine Landi ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Cycle ◽  
Batch Culture ◽  
Time Course ◽  
Reference Model ◽  
Product Yield ◽  
Fed Batch ◽  
Yeast Saccharomyces Cerevisiae ◽  
Biotechnological Processes ◽  
Fed Batch Culture

The yeast Saccharomyces cerevisiae is a reference model system and one of the widely used microorganisms in many biotechnological processes. In industrial yeast applications, combined strategies aim to maximize biomass/product yield, with the fed-batch culture being one of the most frequently used. Flow cytometry (FCM) is widely applied in biotechnological processes and represents a key methodology to monitor cell population dynamics. We propose here an application of FCM in the analysis of yeast cell cycle along the time course of a typical S. cerevisiae fed-batch culture. We used two different dyes, SYTOX Green and SYBR Green, with the aim to better define each stage of cell cycle during S. cerevisiae fed-batch culture. The results provide novel insights in the use of FCM cell cycle analysis for the real-time monitoring of S. cerevisiae bioprocesses.

Bouquet formation in budding yeast: initiation of recombination is not required for meiotic telomere clustering

1999 ◽  
Vol 112 (5) ◽  
pp. 651-658 ◽  
Author(s):  
E. Trelles-Sticken ◽  
J. Loidl ◽  
H. Scherthan
Keyword(s):  
Saccharomyces Cerevisiae ◽  
In Situ Hybridization ◽  
Time Course ◽  
Spindle Pole Body ◽  
Spindle Pole ◽  
Conformational State ◽  
Chromosome Territories ◽  
Yeast Saccharomyces Cerevisiae ◽  
Pole Body

Fluorescence in situ hybridization in combination with synaptonemal complex and spindle pole body immunostaining to both spread and structurally preserved nuclei from time course experiments disclosed prominent telomere clustering during meiotic prophase of the yeast Saccharomyces cerevisiae. It was found that centromere clustering, which dominates vegetative nuclear structure, is rapidly lost after induction of meiosis. Telomeres tightly clustered during leptotene/zygotene-equivalent stages in the vicinity of the spindle pole body, giving rise to a classical chromosomal bouquet arrangement. This arrangement dissolved later during prophase. Painting of chromosomes XI revealed that initially compacted chromosome territories adopt an outstretched morphology in bouquet nuclei. This conformational state was associated with alignment and pairing. Chromosome condensation during pachytene rendered condensed and compact bivalents, and dispersed telomeres. Both the spo11 and rad50S recombination mutants formed bouquets, demonstrating that bouquet formation is recombination and synapsis independent.

scholarly journals Effect of stress on the life span of the yeast Saccharomyces cerevisiae.

2000 ◽  
Vol 47 (2) ◽  
pp. 355-364 ◽  
Author(s):  
A Swieciło ◽  
Z Krawiec ◽  
J Wawryn ◽  
G Bartosz ◽  
T Biliński
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Life Span ◽  
Yeast Cells ◽  
Wild Type ◽  
Maximum Life Span ◽  
Yeast Saccharomyces Cerevisiae ◽  
Yeast Strains ◽  
Resistance To Stress ◽  
The Mean ◽  
C 30

A correlation is known to exist in yeast and other organisms between the cellular resistance to stress and the life span. The aim of this study was to examine whether stress treatment does affect the generative life span of yeast cells. Both heat shock (38 degrees C, 30 min) and osmotic stress (0.3 M NaCl, 1 h) applied cyclically were found to increase the mean and maximum life span of Saccharomyces cerevisiae. Both effects were more pronounced in superoxide dismutase-deficient yeast strains (up to 50% prolongation of mean life span and up to 30% prolongation of maximum life span) than in their wild-type counterparts. These data point to the importance of the antioxidant barrier in the stress-induced prolongation of yeast life span.

EARLY VARIATIONS OF PLASMA CORTISOL AFTER PULSE INTRAVENOUS INJECTION OF DIBUTYRYL CYCLIC ADENOSINE 3′,5′-MONOPHOSPHATE IN NORMAL SUBJECTS

1973 ◽  
Vol 72 (4) ◽  
pp. 753-761 ◽  
Author(s):  
Alberto Angeli ◽  
Giuseppe Boccuzzi ◽  
Roberto Frajria ◽  
Daniela Bisbocci ◽  
Franco Ceresa
Keyword(s):  
Intravenous Injection ◽  
Plasma Cortisol ◽  
Time Course ◽  
Healthy Adult ◽  
Normal Subjects ◽  
Adult Women ◽  
Healthy Women ◽  
Adrenal Steroidogenesis ◽  
The Mean ◽  
Zero Time

ABSTRACT 10 mg/kg of dibutyryl cyclic adenosine 3′,5′-monophosphate (Db-cAMP) was iv pulse injected into twelve healthy adult women. The plasma cortisol levels were determined as 11-OHCS at zero time and then at 2.5, 5, 7.5, 10, 15, 30, 60 and 180 min after the injection. The data were compared with those obtained at the corresponding times in two groups of eleven and seventeen healthy women after the injection of 250 ng and 250 μg of synthetic β-1-24 corticotrophin performed in the same manner as the injection of the nucleotide. The mean increments in plasma cortisol were significantly lower after Db-cAMP than after ACTH. Differences were noted by analyzing the time course of the responses. In the case of stimulation with Db-cAMP the 11-OHCS levels rose progressively to a maximum at 15–30 min. By contrast, a peak of plasma cortisol was evident in most cases within a few min after the injection of ACTH; after a fall, a later rise was then observed starting from 15 min. The differences in the plasma 11-OHCS responses after the two stimuli may also be of interest clinically for the investigation of some aspects of adrenal steroidogenesis.

PREPARASI DEINOCOCCUS RADIODURANS DAN KHAMIR DALAM MATERIAL KECAP L-DRYING SEBAGAI BAHAN UJI PROFISIENSI

2016 ◽  
Vol 13 (1) ◽  
pp. 93
Author(s):  
Titin Yulinery ◽  
Ratih M.Dewi
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Deinococcus Radiodurans ◽  
Test Preparation ◽  
Quality Parameters ◽  
Soy Sauce ◽  
Yeast Saccharomyces Cerevisiae ◽  
Microbiological Test ◽  
Bacterial Contaminants ◽  
Minimum Number ◽  
Important Quality

Tes kemampuan adalah salah satu kegiatan penting dalam pengendalian mutu dan jaminan kualitas mikrobiologi laboratorium untuk mengukur kompetensi analis dan analisis uji profisiensi membutuhkan persiapan Model mikroorganisme adalah kualitas standar dan validitas. Mikrobiologi uji kualitas produk kedelai utama diarahkan pada kehadiran Saccharomyces cerevisiae ragi (S. cerevisiae), S. Bailli, S. rouxii dankontaminan bakteri seperti Bacillus dan Deinococcus. Jenis ragi dan bakteri yang terlibat dalam proses dan dapat menjadi salah satu parameter kualitas penting dalam persiapan yang dihasilkan. Jumlah dan viabilitas bakteri dan ragi menjadi parameter utama dalam proses persiapan bahan uji. Jumlah tersebut adalah jumlah minimum yang berlaku dapat dianalisis. Jumlah ini harus dibawah 10 CFU diperlukan untuk menunjukkan tingkat hygienitas proses dan tingkat minimal kontaminasi. Viabilitas bakteri dan bahan tes ragi persiapan untuk tes kemahiran kecap yang diawetkan dengan L-pengeringan adalah teknik Deinococcus radiodurans (D. radiodurans) 16 tahun, 58 tahun S. cerevisiae, dan S. roxii 13 tahun. kata kunci: Viabilitas, Deinococcus, khamir, L-pengeringan, Proficiency AbstractProficiency test is one of the important activities in quality control and quality assurance microbiology laboratory for measuring the competence of analysts and analysis Proficiency test requires a model microorganism preparations are standardized quality and validity. Microbiological test of the quality of the main soy products aimed at thepresence of yeast Saccharomyces cerevisiae (S. cerevisiae), S. bailli, S. rouxii and bacterial contaminants such as Bacillus and Deinococcus. Types of yeasts and bacteria involved in the process and can be one of the important quality parameters in the preparation produced. The number and viability of bacteria and yeasts become themain parameters in the process of test preparation materials. The amount in question is the minimum number that is valid can be analyzed. This amount must be below 10 CFU required to indicate the level of hygienitas process and the minimum level of contamination. Viability of bacteria and yeast test preparation materials for proficiencytest of soy sauce that preserved by L-drying technique is Deinococcus radiodurans ( D. radiodurans ) 16 years, 58 years S. cerevisiae, and S. roxii 13 years. key words : Viability, Deinococcus, Khamir, L-drying, Proficiency

INTERACTION OF THE HIM1 GENE PRODUCT WITH HELICASES Srs2 (RadH) AND Mph1 YEAST SACCHAROMYCES CEREVISIAE

Tsitologiya ◽  
2018 ◽  
Vol 60 (7) ◽  
pp. 555-557 ◽  
Author(s):  
E. A. Alekseeva ◽  
◽  
T. A. Evstyukhina ◽  
V. T. Peshekhonov ◽  
V. G. Korolev ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Gene Product ◽  
Yeast Saccharomyces Cerevisiae
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