On the Types of Bacterial Growth Laws

2015 ◽  
Vol 10 (1) ◽  
pp. 154-163
Author(s):  
В.А. Лихошвай ◽  
V.A. Likhoshvai
Keyword(s):  
Bacterial Growth ◽  
Universal Principle ◽  
Linear Type ◽  
Size Growth ◽  
Unlimited Growth ◽  
Growth Laws ◽  
Bacterial Cell Cycle ◽  
Living Organisms ◽  
Modern Form ◽  
Bacterial Growth Laws

Volume, mass and envelope surface area of a bacterium are significant parameters of cell development during one bacterial cell cycle. In our previous studies it was shown that during one division cycle cells can encounter the problem of unlimited size growth. Two fundamental types of bacterial growth laws, which were called “exponential” and “linear”, have been identified. Under certain conditions exponentially growing cells encounter the problem of unlimited growth, whereas lineally growing cells don’t. In this study the laws of bacterial size growth were shown to belong exclusively to the linear type. It was demonstrated that this phenomenon is a consequence of the universal principle of storage and transmission of genetic information essential to all living organisms. The bacterial growth laws of exponential type could exist only at the very early stages of cell evolution, when the genetic machinery had not evolved yet into its modern form.

scholarly journals A unifying autocatalytic network-based framework for bacterial growth laws

2021 ◽  
Vol 118 (33) ◽  
pp. e2107829118
Author(s):  
Anjan Roy ◽  
Dotan Goberman ◽  
Rami Pugatch
Keyword(s):  
Growth Rate ◽  
Rna Polymerase ◽  
Bacterial Growth ◽  
Temperature Perturbation ◽  
Protein Ratio ◽  
C Protein ◽  
Protein Subunits ◽  
The Core ◽  
Growth Laws ◽  
Bacterial Growth Laws

Recently discovered simple quantitative relations, known as bacterial growth laws, hint at the existence of simple underlying principles at the heart of bacterial growth. In this work, we provide a unifying picture of how these known relations, as well as relations that we derive, stem from a universal autocatalytic network common to all bacteria, facilitating balanced exponential growth of individual cells. We show that the core of the cellular autocatalytic network is the transcription–translation machinery—in itself an autocatalytic network comprising several coupled autocatalytic cycles, including the ribosome, RNA polymerase, and transfer RNA (tRNA) charging cycles. We derive two types of growth laws per autocatalytic cycle, one relating growth rate to the relative fraction of the catalyst and its catalysis rate and the other relating growth rate to all the time scales in the cycle. The structure of the autocatalytic network generates numerous regimes in state space, determined by the limiting components, while the number of growth laws can be much smaller. We also derive a growth law that accounts for the RNA polymerase autocatalytic cycle, which we use to explain how growth rate depends on the inducible expression of the rpoB and rpoC genes, which code for the RpoB and C protein subunits of RNA polymerase, and how the concentration of rifampicin, which targets RNA polymerase, affects growth rate without changing the RNA-to-protein ratio. We derive growth laws for tRNA synthesis and charging and predict how growth rate depends on temperature, perturbation to ribosome assembly, and membrane synthesis.

Mathematical modeling of bacterial cell cycle: The problem of coordinating genome replication with cell growth

2014 ◽  
Vol 12 (03) ◽  
pp. 1450009 ◽  
Author(s):  
Vitaly A. Likhoshvai ◽  
Tamara M. Khlebodarova
Keyword(s):  
Cell Cycle ◽  
Dna Replication ◽  
Cell Growth ◽  
Growth Rates ◽  
Bacterial Cell ◽  
Genome Replication ◽  
Linear Type ◽  
A Cell ◽  
Growth Laws ◽  
Bacterial Cell Cycle

In this paper, we perform an analysis of bacterial cell-cycle models implementing different strategies to coordinately regulate genome replication and cell growth dynamics. It has been shown that the problem of coupling these processes does not depend directly on the dynamics of cell volume expansion, but does depend on the type of cell growth law. Our analysis has distinguished two types of cell growth laws, "exponential" and "linear", each of which may include both exponential and linear patterns of cell growth. If a cell grows following a law of the "exponential" type, including the exponential V(t) = V0exp (kt) and linear V(t) = V0(1 + kt) dynamic patterns, then the cell encounters the problem of coupling growth rates and replication. It has been demonstrated that to solve the problem, it is sufficient for a cell to have a repressor mechanism to regulate DNA replication initiation. For a cell expanding its volume by a law of the "linear" type, including exponential V(t) = V0+ V1exp (kt) and linear V(t) = V0+ kt dynamic patterns, the problem of coupling growth rates and replication does not exist. In other words, in the context of the coupling problem, a repressor mechanism to regulate DNA replication, and cell growth laws of the "linear" type displays the attributes of universality. The repressor-type mechanism allows a cell to follow any growth dynamic pattern, while the "linear" type growth law allows a cell to use any mechanism to regulate DNA replication.

scholarly journals Bacterial growth laws and their applications

2011 ◽  
Vol 22 (4) ◽  
pp. 559-565 ◽  
Author(s):  
Matthew Scott ◽  
Terence Hwa
Keyword(s):  
Bacterial Growth ◽  
Growth Laws ◽  
Bacterial Growth Laws

scholarly journals Cellular perception of growth rate and the mechanistic origin of bacterial growth laws

2021 ◽  
Author(s):  
Chenhao Wu ◽  
Rohan Balakrishnan ◽  
Matteo Mori ◽  
Gabriel Manzanarez ◽  
Zhongge Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Ribosome Biogenesis ◽  
Broad Class ◽  
E Coli ◽  
Regulatory Circuit ◽  
Cellular Behaviors ◽  
Growth Laws ◽  
Growth Transitions ◽  
Bacterial Growth Laws

Cells organize many of their activities in accordance to how fast they grow. Yet it is not clear how they perceive their rate of growth, which involves thousands of reactions. Through quantitative studies of E. coli under exponential growth and during growth transitions, here we show that the alarmone ppGpp senses the rate of translational elongation by ribosomes, and together with its roles in controlling ribosome biogenesis and activity, closes a key regulatory circuit that enables the cell to perceive the rate of its own growth for a broad class of growth-limiting conditions. This perception provides the molecular basis for the emergence of simple relations among the cellular ribosome content, translational elongation rate, and the growth rate, as manifested by bacterial growth laws. The findings here provide a rare view of how cells manage to collapse the complex, high-dimensional dynamics of the underlying molecular processes to perceive and regulate emergent cellular behaviors, an example of dimension reduction performed by the cells themselves.

scholarly journals Bacterial growth laws reflect the evolutionary importance of energy efficiency

2014 ◽  
Vol 112 (2) ◽  
pp. 406-411 ◽  
Author(s):  
Arijit Maitra ◽  
Ken A. Dill
Keyword(s):  
Energy Efficiency ◽  
Bacterial Growth ◽  
Growth Conditions ◽  
High Energy ◽  
Fast Growth ◽  
Growth Speed ◽  
Energy Costs ◽  
Extensive Literature ◽  
E Coli ◽  
Growth Laws

We are interested in the balance of energy and protein synthesis in bacterial growth. How has evolution optimized this balance? We describe an analytical model that leverages extensive literature data on growth laws to infer the underlying fitness landscape and to draw inferences about what evolution has optimized inEscherichia coli. IsE. colioptimized for growth speed, energy efficiency, or some other property? Experimental data show that at its replication speed limit,E. coliproduces about four mass equivalents of nonribosomal proteins for every mass equivalent of ribosomes. This ratio can be explained if the cell’s fitness function is the the energy efficiency of cells under fast growth conditions, indicating a tradeoff between the high energy costs of ribosomes under fast growth and the high energy costs of turning over nonribosomal proteins under slow growth. This model gives insight into some of the complex nonlinear relationships between energy utilization and ribosomal and nonribosomal production as a function of cell growth conditions.

scholarly journals Diamagnetic levitation enhances growth of liquid bacterial cultures by increasing oxygen availability

2010 ◽  
Vol 8 (56) ◽  
pp. 334-344 ◽  
Author(s):  
Camelia E. Dijkstra ◽  
Oliver J. Larkin ◽  
Paul Anthony ◽  
Michael R. Davey ◽  
Laurence Eaves ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Bacterial Growth ◽  
Liquid Culture ◽  
Superconducting Magnet ◽  
Growth Cycle ◽  
Oxygen Availability ◽  
Bacterial Cultures ◽  
Diamagnetic Levitation ◽  
Living Organisms ◽  
Physical Phenomena

Diamagnetic levitation is a technique that uses a strong, spatially varying magnetic field to reproduce aspects of weightlessness, on the Earth. We used a superconducting magnet to levitate growing bacterial cultures for up to 18 h, to determine the effect of diamagnetic levitation on all phases of the bacterial growth cycle. We find that diamagnetic levitation increases the rate of population growth in a liquid culture and reduces the sedimentation rate of the cells. Further experiments and microarray gene analysis show that the increase in growth rate is owing to enhanced oxygen availability. We also demonstrate that the magnetic field that levitates the cells also induces convective stirring in the liquid. We present a simple theoretical model, showing how the paramagnetic force on dissolved oxygen can cause convection during the aerobic phases of bacterial growth. We propose that this convection enhances oxygen availability by transporting oxygen around the liquid culture. Since this process results from the strong magnetic field, it is not present in other weightless environments, e.g. in Earth orbit. Hence, these results are of significance and timely to researchers considering the use of diamagnetic levitation to explore effects of weightlessness on living organisms and on physical phenomena.

scholarly journals Effect of Frequency Magnetic field on Gram Positive and Gram Negative Bacteria

2019 ◽  
Author(s):  
Mohamad Reza Bayatiani ◽  
fatemeh seif ◽  
mohamad Arjomandzadegan ◽  
alireza moradabadi ◽  
arash parvin
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Bacterial Growth ◽  
Electromagnetic Waves ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Living Organisms ◽  
Escherichia Coli Bacteria ◽  
Growth Of Bacteria

Abstract Objective It is necessary to evaluate the harmful or useful effects of electromagnetic waves on living organisms and determine the threshold of these radiations. In this research, the effect of magnetic fields on the growth of gram-positive ( Staphylococcus aureus ) and gram-negative ( Escherichia coli ) bacteria has been evaluated.Results In Gram-negative bacteria such as E. coli in both magnetic fields 1mT and 2mT at different frequencies, an additive effect was seen on the growth of bacteria. When the frequency increased the trend of increasing bacterial growth, slowed. In Gram-positive bacteria such as Staphylococcus, this effect was less. In 1mT magnetic field, the growth of bacteria was seen but the 2mT field was virtually ineffective and the differences between two groups at different frequencies were not significant. Also, significant changes didn't observe with increasing frequency. Study of bacterial growth in terms of frequency in both case and control groups showed an increasing trend. With increasing frequency from 50 Hz to 150Hz significantly increased the rate of bacterial growth and the growth in the higher frequencies more than lower frequencies. Magnetic field had increment effect on the growth of bacteria. This effect was greater on gram-negative than on gram-positive.

scholarly journals Frequency Electromagnetic field effects on Gram-Positive and Gram-Negative Bacteria

2019 ◽  
Author(s):  
Mohamad Reza Bayatiani ◽  
fatemeh seif ◽  
mohamad Arjomandzadegan ◽  
alireza moradabadi ◽  
arash parvin
Keyword(s):  
Electromagnetic Field ◽  
Bacterial Growth ◽  
Electromagnetic Waves ◽  
Control Group ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Living Organisms ◽  
Escherichia Coli Bacteria ◽  
And Control

Abstract Abstract Objective: The effects of electromagnetic waves on the growth of living organisms and the determination of the threshold of these radiations have remained elusive. Therefore, in this research, we have investigated the growth rate of gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria that had been exposed to the different frequencies of electromagnetic fields. Results: The more frequency increased the slower bacteria grew; however, in gram-positive bacteria such as S. aureus, this effect was seen less. The effect of the 1mT electromagnetic field in the growth of S. aureus was significant between the two groups, nonetheless, in the 2mT electromagnetic field, the effect was not significant between the two groups at different frequencies. Noteworthy, no significant change was observed by increasing the frequency in S. aureus exposed bacteria in comparison to the control group. The study of bacterial growth in terms of frequency in both case and control groups showed an increasing trend. Increasing the frequency from 50 Hz to 150Hz, significantly, enhanced the rate of bacterial growth. On the whole, the magnetic field had an increment effect on the growth of bacteria; in fact, this effect was greater on the gram-negative than on the gram-positive bacteria.

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