scholarly journals Dolichyl phosphate phosphatase from Tetrahymena pyriformis

1981 ◽  
Vol 197 (1) ◽  
pp. 233-238 ◽  
Author(s):  
G S Adrian ◽  
R W Keenan
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Tetrahymena Pyriformis ◽  
Enzymic Activity ◽  
The Other ◽  
Exponential Growth Phase ◽  
Lag Phase ◽  
Mitochondrial Membranes ◽  
Dolichyl Phosphate ◽  
Regulation Of Synthesis

A soluble dolichyl phosphate phosphatase from Tetrahymena pyriformis was purified about 68-fold. The enzyme appeared to be specific for dolichyl phosphate and existed in two interrelated forms, one of mol.wt. about 500000 and the other of mol.wt. about 63000. The enzyme was strongly inhibited by 5 mM-Mn2+ and was strongly stimulated by Mg2+. Tetrahymena in the exponential growth phase contained more of this enzymic activity than cells in stationary or lag phase. The dolichyl phosphate phosphatase may be loosely bound to mitochondrial membranes. Two roles proposed for this enzyme are (1) that of releasing dolichol from its phosphorylated biosynthetic form for its use in the cell as unesterified dolichol or dolichyl ester and/or (2) that of regulation of synthesis of glycoproteins or some other glycosylated compound.

Modeling the Physiological State of the Inoculum and CO2 Atmosphere on the Lag Phase and Growth Rate of Listeria monocytogenes

2008 ◽  
Vol 71 (9) ◽  
pp. 1915-1918 ◽  
Author(s):  
ANTONIO J. DE JESÚS ◽  
RICHARD C. WHITING
Keyword(s):  
Stationary Phase ◽  
Growth Phase ◽  
Growth Rates ◽  
Exponential Growth ◽  
Physiological State ◽  
Brain Heart Infusion ◽  
Exponential Growth Phase ◽  
Lag Phase ◽  
Co2 Concentrations ◽  
Co2 Atmosphere

In previous studies, the growth of L. monocytogenes has been modeled under different CO2 headspace concentrations; however, the inoculum cells were always in the stationary phase. In this study, the growth of L. monocytogenes under different CO2 concentrations as affected by the physiological state of the cells was investigated. Exponential-growth-phase, stationary-phase, dried, and starved cells were prepared and inoculated at 5°C into brain heart infusion broths that had been preequilibrated under atmospheres of 0, 20, 40, 60, or 80% CO2 (the balance was N2). Lag-phase duration times (LDTs) and exponential growth rates were determined by enumerating cells at appropriate time intervals and by fitting the data to a three-phase linear function that has a lag period before the initiation of exponential growth. Longer LDTs were observed as the CO2 concentration increased, with no growth observed at 80% CO2. For example, the LDTs for exponential-phase, stationary-phase, starved, and dried cells were 2.21, 8.27, 9.17, and 9.67 days, respectively, under the 40% CO2 atmosphere. In general, exponential-growth-phase cells had the shortest LDT followed by starved cells and stationary-phase cells. Dried cells had the longest LDT. Exponential growth rates decreased as the CO2 concentrations increased. Once exponential growth was attained, no retained differences among the various initial physiological states of the cells for any of the atmospheres were observed in the exponential growth rates. The exponential growth rates under 0, 20, 40, 60, and 80% CO2 averaged 0.39, 0.37, 0.23, 0.23, and 0.0 log CFU/day, respectively. Dimensionless factors were calculated that describe the inhibitory action of CO2 on the LDTs and exponential growth rates for the various physiological states.

Activation of the expression of the microcin C51 operon upon glucose starvation of cells at the exponential growth phase

2005 ◽  
Vol 41 (1) ◽  
pp. 40-43
Author(s):  
A. M. Veselovskii ◽  
A. Z. Metlitskaya ◽  
V. A. Lipasova ◽  
I. A. Bass ◽  
I. A. Khmel
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Exponential Growth Phase ◽  
Glucose Starvation

scholarly journals Differences in power-law growth over time and indicators of COVID-19 pandemic progression worldwide

2020 ◽  
Author(s):  
Jack Merrin
Keyword(s):  
Error Analysis ◽  
Real Time ◽  
Power Law ◽  
Growth Phase ◽  
Exponential Growth ◽  
Spreading Rate ◽  
Exponential Growth Phase ◽  
Power Law Exponent ◽  
Disease Spreading ◽  
Over Time

1AbstractAn automated statistical and error analysis of 45 countries or regions with more than 1000 cases of COVID-19 as of March 28, 2020, has been performed. This study reveals differences in the rate of disease spreading rate over time in different countries. This survey observes that most countries undergo a beginning exponential growth phase, which transitions into a power-law phase, as recently suggested by Ziff and Ziff. Tracking indicators of growth, such as the power-law exponent, are a good indication of the relative danger different countries are in and show when social measures are effective towards slowing the spread. The data compiled here are usefully synthesizing a global picture, identifying country to country variation in spreading, and identifying countries most at risk. This analysis may factor into how best to track the effectiveness of social distancing policies and quarantines in real-time as data is updated each day.

scholarly journals Biosynthesis and turnover of outer-membrane proteins in Escherichia coli ML308-225

1979 ◽  
Vol 182 (2) ◽  
pp. 407-412 ◽  
Author(s):  
R J Allen ◽  
G K Scott
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Outer Membrane ◽  
Bacterial Growth ◽  
Growth Phase ◽  
Exponential Growth ◽  
Outer Membrane Proteins ◽  
Exponential Growth Phase ◽  
Outer Membranes ◽  
Dilution Experiments

Isolated outer membranes and outer-membrane extracts from Escherichia coli ML308-225 in the early-exponential growth phase contain more protein than do corresponding preparations from late-exponential- or stationary-phase bacteria. Isotope-dilution experiments show that this is due to a loss of protein from the membrane during the exponential growth phase. Inhibition of bacterial growth and protein synthesis stabilizes the outer-membrane-protein concentration. Protein synthesis in the absence of bacterial growth results in higher concentrations of protein in the outer membrane.

Exponential growth phase ofPseudomonas methanolica batch cultures

1973 ◽  
Vol 13 (6) ◽  
pp. 523-528 ◽  
Author(s):  
E. M. Shulgovskaya ◽  
I. I. Ivanova ◽  
G. G. Sotnicov
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Exponential Growth Phase ◽  
Batch Cultures

scholarly journals The Putrescine Importer PuuP of Escherichia coli K-12

2009 ◽  
Vol 191 (8) ◽  
pp. 2776-2782 ◽  
Author(s):  
Shin Kurihara ◽  
Yuichi Tsuboi ◽  
Shinpei Oda ◽  
Hyeon Guk Kim ◽  
Hidehiko Kumagai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Cluster ◽  
Growth Phase ◽  
Exponential Growth ◽  
Minimal Medium ◽  
Exponential Growth Phase ◽  
E Coli ◽  
Genes Encoding ◽  
K 12 ◽  
Utilization Pathway

ABSTRACT The Puu pathway is a putrescine utilization pathway involving gamma-glutamyl intermediates. The genes encoding the enzymes of the Puu pathway form a gene cluster, the puu gene cluster, and puuP is one of the genes in this cluster. In Escherichia coli, three putrescine importers, PotFGHI, PotABCD, and PotE, were discovered in the 1990s and have been studied; however, PuuP had not been discovered previously. This paper shows that PuuP is a novel putrescine importer whose kinetic parameters are equivalent to those of the polyamine importers discovered previously. A puuP + strain absorbed up to 5 mM putrescine from the medium, but a ΔpuuP strain did not. E. coli strain MA261 has been used in previous studies of polyamine transporters, but PuuP had not been identified previously. It was revealed that the puuP gene of MA261 was inactivated by a point mutation. When E. coli was grown on minimal medium supplemented with putrescine as the sole carbon or nitrogen source, only PuuP among the polyamine importers was required. puuP was expressed strongly when putrescine was added to the medium or when the puuR gene, which encodes a putative repressor, was deleted. When E. coli was grown in M9-tryptone medium, PuuP was expressed mainly in the exponential growth phase, and PotFGHI was expressed independently of the growth phase.

scholarly journals Functional elucidation of the non-coding RNAs of Kluyveromyces marxianus in the exponential growth phase

BMC Genomics ◽  
2016 ◽  
Vol 17 (1) ◽  
Author(s):  
Yoo-Bok Cho ◽  
Eun Ju Lee ◽  
Suhyung Cho ◽  
Tae Yong Kim ◽  
Jin Hwan Park ◽  
...  
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Kluyveromyces Marxianus ◽  
Exponential Growth Phase ◽  
Non Coding Rnas

Soy Peptides Enhance Heterologous Membrane Protein Productivity during the Exponential Growth Phase ofSaccharomyces cerevisiae

2012 ◽  
Vol 76 (3) ◽  
pp. 628-631 ◽  
Author(s):  
Keisuke ITO ◽  
Aya HIKIDA ◽  
Sayuri KITAGAWA ◽  
Takumi MISAKA ◽  
Keiko ABE ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Growth Phase ◽  
Exponential Growth ◽  
Exponential Growth Phase ◽  
Soy Peptides ◽  
Protein Productivity
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