Proteome reallocation in Escherichia coli with increasing specific growth rate

In batch cultures of Escherichia coli, the intracellular concentration of the general stress response sigma factor RpoS typically increases during the transition from the exponential to the stationary growth phase. However, because this transition is accompanied by complex physico-chemical and biological changes, which signals predominantly elicit this induction is still the subject of debate. Careful design of the growth environment in chemostat and batch cultures allowed the separate study of individual factors affecting RpoS. Specific growth rate, and not cell density or the nature of the growth-limiting nutrient, controlled RpoS expression and RpoS-dependent hydroperoxidase activity. Furthermore, it was demonstrated that the standard E. coli minimal medium A (MMA) is not suitable for high-cell-density cultivation because it lacks trace elements. Previously reported cell-density effects in chemostat cultures of E. coli can be explained by a hidden, secondary nutrient limitation, which points to the importance of medium design and appropriate experimental set-up for studying cell-density effects.

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Growth kinetics of Escherichia coli with galactose and several other sugars in carbon-limited chemostat culture

Canadian Journal of Microbiology ◽

10.1139/w99-113 ◽

1999 ◽

Vol 46 (1) ◽

pp. 72-80 ◽

Cited By ~ 3

Author(s):

Urs Lendenmann ◽

Mario Snozzi ◽

Thomas Egli

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Steady State ◽

Specific Growth Rate ◽

Growth Kinetics ◽

Specific Growth ◽

Chemostat Culture ◽

Monod Model ◽

E Coli ◽

Kinetics Of

Kinetic models for microbial growth describe the specific growth rate (μ) as a function of the concentration of the growth-limiting nutrient (s) and a set of parameters. A typical example is the model proposed by Monod, where μ is related to s using substrate affinity (Ks) and the maximum specific growth rate (μmax). The preferred method to determine such parameters is to grow microorganisms in continuous culture and to measure the concentration of the growth-limiting substrate as a function of the dilution rate. However, owing to the lack of analytical methods to quantify sugars in the microgram per litre range, it has not been possible to investigate the growth kinetics of Escherichia coli in chemostat culture. Using an HPLC method able to determine steady-state concentrations of reducing sugars, we previously have shown that the Monod model adequately describes glucose-limited growth of E. coli ML30. This has not been confirmed for any other sugar. Therefore, we carried out a similar study with galactose and found steady-state concentrations between 18 and 840 μg·L-1 for dilution rates between 0.2 and 0.8·h-1, respectively. With these data the parameters of several models giving the specific growth rate as a function of the substrate concentration were estimated by nonlinear parameter estimation, and subsequently, the models were evaluated statistically. From all equations tested, the Monod model described the data best. The parameters for galactose utilisation were μmax = 0.75·h-1 and Ks = 67 μg·L-1. The results indicated that accurate Ks values can be estimated from a limited set of steady-state data when employing μmax measured during balanced growth in batch culture. This simplified procedure was applied for maltose, ribose, and fructose. For growth of E. coli with these sugars, μmax and Ks were for maltose 0.87·h-1, 100 μg·L-1; for ribose 0.57·h-1, 132 μg·L-1, and for fructose 0.70·h-1, 125 μg·L-1. Key words: monod model, continuous culture, galactose, glucose, fructose, maltose, ribose.

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Specific Growth Rate Determines the Sensitivity of Escherichia coli to Thermal, UVA, and Solar Disinfection

Applied and Environmental Microbiology ◽

10.1128/aem.72.4.2586-2593.2006 ◽

2006 ◽

Vol 72 (4) ◽

pp. 2586-2593 ◽

Cited By ~ 144

Author(s):

Michael Berney ◽

Hans-Ulrich Weilenmann ◽

Julian Ihssen ◽

Claudio Bassin ◽

Thomas Egli

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Specific Growth Rate ◽

Growth Rates ◽

Specific Growth ◽

E Coli ◽

Mild Heat ◽

Uva Light ◽

Specific Growth Rates ◽

Slow Growing

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.

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Slow post-induction specific growth rate enhances recombinant protein expression in Escherichia coli: Pramlintide multimer and ranibizumab production as case studies

Process Biochemistry ◽

10.1016/j.procbio.2022.01.009 ◽

2022 ◽

Author(s):

Jashwant Kumar ◽

Sami U. Bhat ◽

Anurag S. Rathore

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Recombinant Protein ◽

Protein Expression ◽

Specific Growth Rate ◽

Case Studies ◽

Specific Growth ◽

Recombinant Protein Expression ◽

Expression In Escherichia Coli ◽

Post Induction

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Effect of specific growth rate on the production of a recombinant nuclease by Escherichia coli

Biochemical Engineering Journal ◽

10.1016/s1369-703x(02)00156-0 ◽

2003 ◽

Vol 14 (2) ◽

pp. 101-107 ◽

Cited By ~ 12

Author(s):

Li-Chun Cheng ◽

Lien-I Hor ◽

Jau-Yann Wu ◽

Teh-Liang Chen

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Specific Growth Rate ◽

Specific Growth

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Influence of specific growth rate over the secretory expression of recombinant potato carboxypeptidase inhibitor in fed-batch cultures of Escherichia coli

Process Biochemistry ◽

10.1016/j.procbio.2010.04.024 ◽

2010 ◽

Vol 45 (8) ◽

pp. 1334-1341 ◽

Cited By ~ 11

Author(s):

Juan-Miguel Puertas ◽

Jordi Ruiz ◽

Mónica Rodríguez de la Vega ◽

Julia Lorenzo ◽

Glòria Caminal ◽

...

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Specific Growth Rate ◽

Specific Growth ◽

Fed Batch ◽

Secretory Expression ◽

Batch Cultures ◽

Carboxypeptidase Inhibitor

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Evolution of Escherichia coli During Growth in a Constant Environment

Genetics ◽

10.1093/genetics/116.3.349 ◽

1987 ◽

Vol 116 (3) ◽

pp. 349-358

Author(s):

Robert B Helling ◽

Christopher N Vargas ◽

Julian Adams

Keyword(s):

Escherichia Coli ◽

Growth Rate ◽

Specific Growth Rate ◽

Continuous Culture ◽

Specific Growth ◽

Maximum Specific Growth Rate ◽

Constant Environment ◽

Single Clone ◽

Mixed Populations

ABSTRACT Populations of Escherichia coli, initiated with a single clone and maintained for long periods in glucose-limited continuous culture, developed extensive polymorphisms. In one population, examined after 765 generations, two majority and two minority types were identified. Stable mixed populations were reestablished from the isolated strains. Factors involved in the development of this polymorphism included differences in the maximum specific growth rate and in the transport of glucose, and excretion of metabolites by some clones which were utilized by minority clones.

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