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 Environmental Growth Conditions Influence the Ability of Escherichia coli K1 To Invade Brain Microvascular Endothelial Cells and Confer Serum Resistance

1998 ◽  
Vol 66 (12) ◽  
pp. 5692-5697 ◽  
Author(s):  
Julie L. Badger ◽  
Kwang Sik Kim
Keyword(s):  
Escherichia Coli ◽  
Endothelial Cells ◽  
Blood Brain Barrier ◽  
Bacterial Growth ◽  
Growth Conditions ◽  
Brain Barrier ◽  
Microvascular Endothelial Cells ◽  
Serum Resistance ◽  
Brain Microvascular Endothelial Cells ◽  
E Coli

ABSTRACT A major limitation to advances in prevention and therapy of neonatal meningitis is our incomplete understanding of the pathogenesis of this disease. In an effort to understand the pathogenesis of meningitis due to Escherichia coli K1, we examined whether environmental growth conditions similar to those that the bacteria might be exposed to in the blood could influence the ability ofE. coli K1 to invade brain microvascular endothelial cells (BMEC) in vitro and to cross the blood-brain barrier in vivo. We found that the following bacterial growth conditions enhanced E. coli K1 invasion of BMEC 3- to 10-fold: microaerophilic growth, media buffered at pH 6.5, and media supplemented with 50% newborn bovine serum (NBS), magnesium, or iron. Growth conditions that significantly repressed invasion (i.e., 2- to 250-fold) included iron chelation, a pH of 8.5, and high osmolarity. More importantly, E. coli K1 traversal of the blood-brain barrier was significantly greater for the growth condition enhancing BMEC invasion (50% NBS) than for the condition repressing invasion (osmolarity) in newborn rats with experimental hematogenous meningitis. Of interest, bacterial growth conditions that enhanced or repressed invasion also elicited similar serum resistance phenotype patterns. This is the first demonstration that bacterial ability to enter the central nervous system can be affected by environmental growth conditions.

scholarly journals Innovative heat-technology of processing phytoestrogenic raw materials into functional powders

2020 ◽  
Vol 84 (1) ◽  
pp. 16-21
Author(s):  
Zhanna Petrova ◽  
Kateryna Slobodianiuk
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Energy Saving ◽  
Raw Materials ◽  
High Energy ◽  
Drying Methods ◽  
Energy Costs ◽  
High Quality ◽  
Heat Technology ◽  
Vegetable Raw Materials

Outdated technologies in drying processes can lead to iПеrrational use of energy, as a consequence, high energy consumption and increased energy consumption. Therefore, the issues of energy saving and energy efficiency are the most important tasks to be solved. Nowadays, energy saving and energy efficiency are also part of the environmental problem. Ukraine, which has a unique geographical position for Europe, is fully supplied with natural resources, - one of the countries where there is inefficient use of energy resources. One of the energy-consuming areas of vegetable processing is drying. In the modern world, the issue of energy efficiency of drying methods is one of the most relevant areas of research. Convective drying of vegetable raw materials requires a rational use of regime parameters of the process corresponding to the biochemical properties of the processed object. The primary objectives of this area of processing of vegetable raw materials are to reduce energy costs and ensure high quality characteristics of the final product. This article presents the developed heat-technology for obtaining phytoestrogenic powder from soybeans and spinach. Which includes 3 stages: preliminary preparation of raw materials for drying; drying of thermolabile vegetable raw materials; dispersion and packaging of the obtained phytoestrogenic powder. As a result of previously conducted comprehensive research, it was found that the use of heat technology reduces energy costs at the stage of preparation of raw materials through the improvement of existing hydrothermal treatment of soybeans, as well as energy savings of 21% through the use of developed step modes. Studies of the qualitative characteristics of the obtained phytoestrogenic powder confirm the high quality of the final product.

scholarly journals Coordination of gene expression with cell size enables Escherichia coli to efficiently maintain motility across conditions

2021 ◽  
Author(s):  
Tomoya Honda ◽  
Jonas Cremer ◽  
Leonardo Mancini ◽  
Zhongge Zhang ◽  
Teuta Pilizota ◽  
...  
Keyword(s):  
Gene Expression ◽  
Escherichia Coli ◽  
Cell Size ◽  
Sensory System ◽  
Size Control ◽  
Growth Conditions ◽  
Fast Growth ◽  
Cellular Motility ◽  
E Coli ◽  
Minimum Number

To swim and navigate, motile bacteria synthesize a complex motility machinery involving flagella, motors, and a sensory system. A myriad of studies has elucidated the molecular processes involved, but less is known about the coordination of motility expression with cellular physiology: In Escherichia coli, motility genes are strongly upregulated in nutrient-poor conditions compared to nutrient-replete conditions; yet a quantitative link to cellular motility has not been developed. Here, we systematically investigate gene expression, swimming behavior, and cell growth across a broad spectrum of exponential growth condition. We establish that E. coli up-regulates the expression of motility genes at slow growth to compensate for reduction in cell size, such that the number of flagella per cell is maintained across conditions. The observed 4-5 flagella per cell is the minimum number needed to keep the majority of cells motile. This simple regulatory objective allows E. coli cells to remain motile across a broad range of growth conditions while keeping the biosynthetic and energetic demands to establish and drive the motility machinery at the minimum needed. Given the strong reduction in flagella synthesis resulting from cell size increases at fast growth, our findings also provide a novel physiological perspective on bacterial cell size control: A larger cell-size at fast growth is an efficient strategy to increase the allocation of cellular resources to the synthesis of those proteins required for fast growth, while maintaining processes such as motility which are only needed on a per-cell basis.

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 Algorithm for reducing energy costs during major repairs of apartment buildings

2020 ◽  
Vol 8 (3) ◽  
pp. 69-72
Author(s):  
Elena Korol ◽  
Ekaterina Timofeeva
Keyword(s):  
Energy Efficiency ◽  
High Energy ◽  
Energy Resources ◽  
Energy Costs ◽  
Manual Labor ◽  
Additional Energy ◽  
Apartment Buildings ◽  
High Energy Efficiency ◽  
Reducing Energy ◽  
Construction Works

Carrying out repair and construction works is associated with additional energy costs in the operated building. Major repairs of buildings are the most energy-intensive. The specificity of these works is the use of manual labor, as well as tools and means of mechanization adapted to the corresponding technological processes of repair and construction production. Given the variety of mechanization tools and specialized tools for major repairs, it is important to solve the problem of calculating and reducing the consumption of fuel and energy resources in the process of work by selecting and using construction equipment and tools of high energy efficiency.

Additional methods to improve the energy efficiency of oil pipeline transportation

2020 ◽  
Vol 10 (5) ◽  
pp. 558-565
Author(s):  
Marat R. Lukmanov ◽  
◽  
Sergey L. Semin ◽  
Pavel V. Fedorov ◽  
◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Energy Saving ◽  
Pipeline System ◽  
Energy Costs ◽  
Improvement Program ◽  
Oil Pipeline ◽  
Energy Efficiency Improvement ◽  
Oil Transportation ◽  
Pumping Equipment ◽  
Preparatory Work

The challenges of increasing the energy efficiency of the economy as a whole and of certain production sectors in particular are a priority both in our country and abroad. As part of the energy policy of the Russian Federation to reduce the specific energy intensity of enterprises in the oil transportation system, Transneft PJSC developed and implements the energy saving and energy efficiency improvement Program. The application of energy-saving technologies allowed the company to significantly reduce operating costs and emissions of harmful substances. At the same time, further reduction of energy costs is complicated for objective reasons. The objective of this article is to present additional methods to improve the energy efficiency of oil transportation by the example of the organizational structure of Transneft. Possibilities to reduce energy costs in the organization of the operating services, planning and execution of work to eliminate defects and preparatory work for the scheduled shutdown of the pipeline, the use of pumping equipment, including pumps with variable speed drive, the use of various pipelines layouts, changing the volume of oil entering the pipeline system and increase its viscosity.

Reactions in Activated Peroxide Systems and their Influences on Bleaching Performance

2020 ◽  
Vol 17 ◽  
Author(s):  
Xiaoyan Wang ◽  
Jinmei Du ◽  
Changhai Xu
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Energy Efficiency ◽  
Textile Industry ◽  
High Energy ◽  
Side Reactions ◽  
Competitive Reactions ◽  
High Energy Efficiency ◽  
Hydrolysis Of ◽  
Bleach Activators

Abstract:: Activated peroxide systems are formed by adding so-called bleach activators to aqueous solution of hydrogen peroxide, developed in the seventies of the last century for use in domestic laundry for their high energy efficiency and introduced at the beginning of the 21st century to the textile industry as an approach toward overcoming the extensive energy consumption in bleaching. In activated peroxide systems, bleach activators undergo perhydrolysis to generate more kinetically active peracids that enable bleaching under milder conditions while hydrolysis of bleach activators and decomposition of peracids may occur as side reactions to weaken the bleaching efficiency. This mini-review aims to summarize these competitive reactions in activated peroxide systems and their influence on bleaching performance.

scholarly journals Influence of nutrient availability on in vitro growth of major bovine mastitis pathogens

2021 ◽  
Vol 88 (1) ◽  
pp. 80-88
Author(s):  
Remo Stürmlin ◽  
Josef J. Gross ◽  
Olga Wellnitz ◽  
Lea A. Wagner ◽  
Camille Monney ◽  
...  
Keyword(s):  
Bacterial Growth ◽  
Nutrient Availability ◽  
Bovine Mastitis ◽  
Milk Composition ◽  
B Vitamins ◽  
E Coli ◽  
Streptococcus Uberis ◽  
Whole Milk ◽  
Mastitis Pathogens

AbstractThe aim of the present study was to investigate the effects of milk composition changes on the in vitro growth of bovine mastitis pathogens. Nutritional requirements of three major bovine mastitis pathogens Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Streptococcus uberis (S. uberis) were investigated in vitro. We used ultra-high temperature (UHT) treated milk with different contents of fat, protein, and carbohydrates to test the influence of the availability of various milk constituents on pathogen growth characteristics. Additionally, the bacterial growth was investigated under experimentally modified nutrient availability by dilution and subsequent supplementation with individual nutrients (carbohydrates, different nitrogen sources, minerals, and different types of B vitamins) either to milk or to a conventional medium (thioglycolate broth, TB). Varying contents of fat, protein or lactose did not affect bacterial growth with the exception of growth of S. uberis being promoted in protein-enriched milk. The addition of nutrients to diluted whole milk and TB partly revealed different effects, indicating that there are media-specific growth limiting factors after dilution. Supplementation of minerals to diluted milk did not affect growth rates of all studied bacteria. Bacterial growth in diluted whole milk was decreased by the addition of high concentrations of amino acids in S. aureus, and by urea and additional B vitamins in E. coli and S. aureus. The growth rate of S. uberis was increased by the addition of B vitamins to diluted whole milk. The present results demonstrate that growth-limiting nutrients differ among pathogen types. Because reduced bacterial growth was only shown in diluted milk or TB, it is unlikely that alterations in nutrient availability occurring as a consequence of physiological changes of milk composition in the cow's udder would directly affect the susceptibility or course of bovine mastitis.

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