Refolding and Structural Characteristic of TRAIL/Apo2L Inclusion Bodies from Different Specific Growth Rates of Recombinant Escherichia coli

2007 ◽  
Vol 23 (1) ◽  
pp. 286-292 ◽  
Author(s):  
H. Kang ◽  
A.-Y. Sun ◽  
Y.-L. Shen ◽  
D.-Z. Wei
Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1413-1426 ◽  
Author(s):  
Robert A. Cox

Further understanding of the physiological states of Mycobacterium tuberculosis and other mycobacteria was sought through comparisons with the genomic properties and macromolecular compositions of Streptomyces coelicolor A3(2), grown at 30 °C, and Escherichia coli B/r, grown at 37 °C. A frame of reference was established based on quantitative relationships observed between specific growth rates (μ) of cells and their macromolecular compositions. The concept of a schematic cell based on transcription/translation coupling, average genes and average proteins was developed to provide an instantaneous view of macromolecular synthesis carried out by cells growing at their maximum rate. It was inferred that the ultra-fast growth of E. coli results from its ability to increase the average number of rRNA (rrn) operons per cell through polyploidy, thereby increasing its capacity for ribosome synthesis. The maximum growth rate of E. coli was deduced to be limited by the rate of uptake and consumption of nutrients providing energy. Three characteristic properties of S. coelicolor A3(2) growing optimally (μ=0·30 h−1) were identified. First, the rate of DNA replication was found to approach the rate reported for E. coli (μ=1·73 h−1); secondly, all rrn operons were calculated to be fully engaged in precursor-rRNA synthesis; thirdly, compared with E. coli, protein synthesis was found to depend on higher concentrations of ribosomes and lower concentrations of aminoacyl-tRNA and EF-Tu. An equation was derived for E. coli B/r relating μ to the number of rrn operons per genome. Values of μ=0·69 h−1 and μ=1·00 h−1 were obtained respectively for cells with one or two rrn operons per genome. Using the author's equation relating the number of rrn operons per genome to maximum growth rate, it is expected that M. tuberculosis with one rrn operon should be capable of growing much faster than it actually does. Therefore, it is suggested that the high number of insertion sequences in this species attenuates growth rate to still lower values.


2013 ◽  
Vol 13 (4) ◽  
pp. 1056-1062 ◽  
Author(s):  
Saeid Rezaeinejad ◽  
Volodymyr Ivanov

The physiological differences of individual cells of bacterial population may imply the existence of cell subpopulations with different sensitivity to chlorine, which may affect the efficiency of drinking water disinfection. The susceptibility of individual bacterial cells to chlorine was examined using flow cytometry. The inactivation of Escherichia coli cells by chlorine in the populations with specific growth rates of 0.2 and 0.9 h−1 was assessed using various viability indicators. Viability of bacterial cells was evaluated using membrane integrity propidium iodide (PI) dye, respiratory activity indicator of 5-cyano-2,3-ditolyl tetrazolium chloride (CTC) and membrane potential probe of DiBAC4(3). It was found that there were cell subpopulations of E. coli with different levels of susceptibility to chlorine. E. coli cell population with higher specific growth rate was more susceptible to chlorine. The CT values for inactivation of 99% of cells (CT99) in populations of E. coli with specific growth rates of 0.9 and 0.2 h−1 were 0.06 and 0.09 mg min l−1, respectively. Flow cytometry could be used to study the sensitivity of bacterial cells to the chemical agents.


2006 ◽  
Vol 72 (4) ◽  
pp. 2586-2593 ◽  
Author(s):  
Michael Berney ◽  
Hans-Ulrich Weilenmann ◽  
Julian Ihssen ◽  
Claudio Bassin ◽  
Thomas Egli

ABSTRACT Knowledge about the sensitivity of the test organism is essential for the evaluation of any disinfection method. In this work we show that sensitivity of Escherichia coli MG1655 to three physical stresses (mild heat, UVA light, and sunlight) that are relevant in the disinfection of drinking water with solar radiation is determined by the specific growth rate of the culture. Batch- and chemostat-cultivated cells from cultures with similar specific growth rates showed similar stress sensitivities. Generally, fast-growing cells were more sensitive to the stresses than slow-growing cells. For example, slow-growing chemostat-cultivated cells (D = 0.08 h−1) and stationary-phase bacteria from batch culture that were exposed to mild heat had very similar T 90 (time until 90% of the population is inactivated) values (T 90, chemostat = 2.66 h; T 90, batch = 2.62 h), whereas T 90 for cells growing at a μ of 0.9 h−1 was 0.2 h. We present evidence that the stress sensitivity of E. coli is correlated with the intracellular level of the alternative sigma factor RpoS. This is also supported by the fact that E. coli rpoS mutant cells were more stress sensitive than the parent strain by factors of 4.9 (mild heat), 5.3 (UVA light), and 4.1 (sunlight). Furthermore, modeling of inactivation curves with GInaFiT revealed that the shape of inactivation curves changed depending on the specific growth rate. Inactivation curves of cells from fast-growing cultures (μ = 1.0 h−1) that were irradiated with UVA light showed a tailing effect, while for slow-growing cultures (μ = 0.3 h−1), inactivation curves with shoulders were obtained. Our findings emphasize the need for accurate reporting of specific growth rates and detailed culture conditions in disinfection studies to allow comparison of data from different studies and laboratories and sound interpretation of the data obtained.


2001 ◽  
Vol 58 (2) ◽  
pp. 386-393 ◽  
Author(s):  
John A Sweka ◽  
Kyle J Hartman

Brook trout (Salvelinus fontinalis) were held in an artificial stream to observe the influence of turbidity on mean daily consumption and specific growth rates. Treatment turbidity levels ranged from clear (<3.0 nephelometric turbidity units (NTU)) to very turbid water (> 40 NTU). Observed mean daily specific consumption rates were standardized to the mean weight of all brook trout tested. Turbidity had no significant effect on mean daily consumption, but specific growth rates decreased significantly as turbidity increased. Brook trout in turbid water became more active and switched foraging strategies from drift feeding to active searching. This switch was energetically costly and resulted in lower specific growth rates in turbid water as compared with clear water. Bioenergetics simulations were run to compare observed growth with that predicted by the model. Observed growth values fell below those predicted by the model and the difference increased as turbidity increased. Abiotic factors, such as turbidity, which bring about changes in the activity rates of fish, can have implications for the accuracy of predicted growth by bioenergetics models.


Copeia ◽  
1992 ◽  
Vol 1992 (4) ◽  
pp. 1098 ◽  
Author(s):  
Alan B. Bolten ◽  
Karen A. Bjorndal ◽  
Janice S. Grumbles ◽  
David W. Owens

2014 ◽  
Vol 17 (2) ◽  
pp. 346-363 ◽  
Author(s):  
Wout Overkamp ◽  
Onur Ercan ◽  
Martijn Herber ◽  
Antonius J. A. van Maris ◽  
Michiel Kleerebezem ◽  
...  

2021 ◽  
Author(s):  
Sevtap Tırınk ◽  
Alper Nuhoğlu ◽  
Sinan Kul

Abstract This study encompasses investigation of treatment of pistachio processing industry wastewaters in a batch reactor under aerobic conditions, calculation of kinetic parameters and comparison of different inhibition models. The mixed microorganism culture used in the study was adapted to pistachio processing industry wastewaters for nearly one month and then concentrations from 50-1000 mg L− 1 of pistachio processing industry wastewaters were added to the medium and treatment was investigated in batch experiments. The Andrews, Han-Levenspiel, Luong and Aiba biokinetic equations were chosen for the correlations between the concentration of pistachio processing industry wastewaters and specific growth rates, and the kinetic parameters in these biokinetic equations were calculated. The µmax, Ks and Ki parameters, included in the Aiba biokinetic equation providing best fit among the other equations, had values calculated as 0.25 h− 1, 19 mg L− 1, and 516 mg L− 1, respectively.


2012 ◽  
Vol 78 (19) ◽  
pp. 7132-7136 ◽  
Author(s):  
Christian Dusny ◽  
Frederik Sven Ole Fritzsch ◽  
Oliver Frick ◽  
Andreas Schmid

ABSTRACTSingularized cells ofPichia pastoris,Hansenula polymorpha, andCorynebacterium glutamicumdisplayed specific growth rates under chemically and physically constant conditions that were consistently higher than those obtained in populations. This highlights the importance of single-cell analyses by uncoupling physiology and the extracellular environment, which is now possible using the Envirostat 2.0 concept.


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