scholarly journals A distinct growth physiology enhances bacterial growth under rapid nutrient fluctuations

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jen Nguyen ◽  
Vicente Fernandez ◽  
Sammy Pontrelli ◽  
Uwe Sauer ◽  
Martin Ackermann ◽  
...  
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Growth Response ◽  
Average Concentration ◽  
Growth Physiology ◽  
E Coli ◽  
Nutrient Environment ◽  
Growth Loss ◽  
Concentration Characteristic ◽  
Cell Microscopy

AbstractIt has long been known that bacteria coordinate their physiology with their nutrient environment, yet our current understanding offers little intuition for how bacteria respond to the second-to-minute scale fluctuations in nutrient concentration characteristic of many microbial habitats. To investigate the effects of rapid nutrient fluctuations on bacterial growth, we couple custom microfluidics with single-cell microscopy to quantify the growth rate of E. coli experiencing 30 s to 60 min nutrient fluctuations. Compared to steady environments of equal average concentration, fluctuating environments reduce growth rate by up to 50%. However, measured reductions in growth rate are only 38% of the growth loss predicted from single nutrient shifts. This enhancement derives from the distinct growth response of cells grown in environments that fluctuate rather than shift once. We report an unexpected physiology adapted for growth in nutrient fluctuations and implicate nutrient timescale as a critical environmental parameter beyond nutrient identity and concentration.

scholarly journals A distinct growth physiology enhances bacterial growth under rapid nutrient fluctuations

2020 ◽  
Author(s):  
Jen Nguyen ◽  
Vicente Fernandez ◽  
Sammy Pontrelli ◽  
Uwe Sauer ◽  
Martin Ackermann ◽  
...  
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Nutrient Concentration ◽  
Growth Response ◽  
Average Concentration ◽  
Growth Physiology ◽  
E Coli ◽  
Growth Loss ◽  
Concentration Characteristic ◽  
Cell Microscopy

AbstractIt has been long known that bacteria coordinate their physiology with environmental nutrient, yet our current understanding offers little intuition for how bacteria respond to the second-to-minute scale fluctuations in nutrient concentration characteristic of many microbial habitats. To investigate the effects of rapid nutrient fluctuations on bacterial growth, we coupled custom microfluidics with single-cell microscopy to quantify the growth rate of E. coli experiencing 30 s to 60 min nutrient fluctuations. Compared to steady environments of equal average concentration, fluctuating environments reduced growth rate by up to 50%. However, measured reductions in growth rate were only 38% of the growth loss predicted from single nutrient shifts — an enhancement produced by the distinct growth response of cells grown in environments that fluctuate rather than shift once. We report an unexpected physiology adapted for growth in nutrient fluctuations and implicate nutrient timescale as a critical environmental parameter beyond nutrient concentration and source.

Effect of Tannins on the In Vitro Growth of Escherichia coli O157:H7 and In Vivo Growth of Generic Escherichia coli Excreted from Steers

2007 ◽  
Vol 70 (3) ◽  
pp. 543-550 ◽  
Author(s):  
BYENG R. MIN ◽  
WILLIAM E. PINCHAK ◽  
ROBIN C. ANDERSON ◽  
TODD R. CALLAWAY
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Bacterial Growth ◽  
Escherichia Coli O157 ◽  
Tannin Extract ◽  
Bacterial Growth Rate ◽  
Linear Effect ◽  
E Coli

The effect of commercially available chestnut and mimosa tannins in vitro (experiment 1) or in vivo (experiment 2) on the growth or recovery of Escherichia coli O157:H7 or generic fecal E. coli was evaluated. In experiment 1, the mean growth rate of E. coli O157:H7, determined via the measurement of optical density at 600 nm during anaerobic culture in tryptic soy broth at 37°C, was reduced (P < 0.05) with as little as 400 μg of either tannin extract per ml of culture fluid. The addition of 200, 400, 600, 800, and 1,200 μg of tannins per ml significantly (P < 0.01) reduced the specific bacterial growth rate when compared with the nontannin control. The specific growth rate decreased with increasing dose levels up to 800 μg of tannins per ml. Bacterial growth inhibition effects in chestnut tannins were less pronounced than in mimosa tannins. Chestnut tannin extract addition ranged from 0 to 1,200 μg/ml, and a linear effect (P < 0.05) was observed in cultures incubated for 6 h against the recovery of viable cells, determined via the plating of each strain onto MacConkey agar, of E. coli O157:H7 strains 933 and 86-24, but not against strain 6058. Similar tests with mimosa tannin extract showed a linear effect (P < 0.05) against the recovery of E. coli O157:H7 strain 933 only. The bactericidal effect observed in cultures incubated for 24 h with the tannin preparations was similar, although it was less than that observed from cultures incubated for 6 h. When chestnut tannins (15 g of tannins per day) were infused intraruminally to steers fed a Bermuda grass hay diet in experiment 2, fecal E. coli shedding was lower on days 3 (P < 0.03), 12 (P = 0.08), and 15 (P < 0.001) when compared with animals that were fed a similar diet without tannin supplementation. It was concluded that dietary levels and sources of tannins potentially reduce the shedding of E. coli from the gastrointestinal tract.

scholarly journals Bioremediation of Diazinon, Pirimicarb and Atrazine Pesticides Using Bacterial Species

2021 ◽  
pp. 14-20
Keyword(s):  
Growth Rate ◽  
Bacterial Growth ◽  
Bacterial Species ◽  
Serial Dilution ◽  
Bacterial Cells ◽  
E Coli ◽  
Highly Efficient

Bacterial species such as E.coli, S. aureus and Sa. bongori were isolated from soil by using serial dilution. Bioremediation results showed the S. aureus was highly efficient on Diazinon removal by 62%, 63.2% and 68.6%, Pirimicarb removal was 44%, 52.4% and 53.8%, and Atrazine removal was 61%, 65.6% and 70.6%. and the efficiency of E.coli removal on Diazinon was 59%, 60.8% and 63.8%; on Pirimicarb was 44%, 52.4% and 53.8%; and for Atrazine 57%, 60.8% and 64.4%. Sa. bongori efficiency on Diazinon was 49%, 51.2% and 55.8%; on Pirimicarb removal was 61%, 63.2% and 68.4%; Also, in Atrazine removal 48%, 50.4% and 57.2%. When comparing the growth rate of bacterial cells. The bacterial cells before treatment with S. aureus was 22.01×10^4, Results after treatment showed Diazinon of 35.58×10^4. The Pirimicarb 32.41×10^4 and Atrazine was 38.45 ×10^4. Either E. coli Its bacterial growth was before treatment 17.09×10^4 To show the results of growth on diazinon 30.43×10^4, Pirimicarb 27.71×10^4 and Atrazine 24.34 ×10^4. While the growth was in Sa. bongori Before treatment 10.09×10^4 While recorded a growth rate on Diazinon 18.82×10^4, Pirimicarb 19.98×10^4 and Atrazine 17.08 ×10^4.These bacterial species efficiencies on bioremediation of these three pesticides proved to be promising It can be used safely in the process of removing pesticides, yet more research on safety, mechanisms and kinetics needs to be further investigated.

scholarly journals Direct Observation and Analysis of Bacterial Growth on an Antimicrobial Surface

2010 ◽  
Vol 76 (16) ◽  
pp. 5409-5414 ◽  
Author(s):  
Hiroyuki Yamada ◽  
Nobuyuki Takahashi ◽  
Shujiro Okuda ◽  
Yuki Tsuchiya ◽  
Hisao Morisaki
Keyword(s):  
Growth Rate ◽  
Rate Constant ◽  
Bacterial Growth ◽  
Nutrient Concentration ◽  
Nutrient Utilization ◽  
Utilization Efficiency ◽  
Nutrient Concentrations ◽  
Growth Rate Constant ◽  
E Coli ◽  
Nutrient Utilization Efficiency

ABSTRACT Cells of Escherichia coli NBRC 3972 and Staphylococcus aureus NBRC 12732 were inoculated onto an agar (1.5%) medium varying in nutrient concentration from full strength of the nutrient broth (NB) to 1/10 NB. Immediately thereafter, the inoculated agar was placed on antimicrobial and nonantimicrobial surfaces in such a way that the microbial cells came into contact with these surfaces. Cell growth was directly observed under a microscope, and the growth rate constant of the cells was measured based on the increase in the area of the colonies formed by the growing cells. On the antimicrobial surface, the growth rate constant decreased at lower nutrient concentrations for both E. coli and S. aureus cells, whereas it showed little change on the nonantimicrobial surface. It was supposed that either the nutrient uptake or the nutrient utilization efficiency was retarded by the antimicrobial surface. At the lowest nutrient concentration examined in the present study, 1/10 NB, the cells could hardly grow on the antimicrobial surface, indicating that the surface would be sufficiently active in preventing bacterial growth under normal usage conditions, such as the wet areas of a kitchen. It was also revealed that the antimicrobial surface could prevent the division of cells either during the growth stage or before the onset of growth.

scholarly journals Growth Rate of Escherichia coli During Human Urinary Tract Infection: Implications for Antibiotic Effect

Antibiotics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 92 ◽  
Author(s):  
Haugan ◽  
Hertz ◽  
Charbon ◽  
Sahin ◽  
Løbner-Olesen ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Rate ◽  
Urinary Tract Infection ◽  
Urinary Tract ◽  
Bacterial Growth ◽  
Chromosome Replication ◽  
Bacterial Growth Rate ◽  
E Coli ◽  
Antibiotic Effect

Escherichia coli is the primary cause of urinary tract infection (UTI), which is one of the most frequent human infections. While much is understood about the virulence factors utilized by uropathogenic E. coli (UPEC), less is known about the bacterial growth dynamics taking place during infection. Bacterial growth is considered essential for successful host colonization and infection, and most antibiotics in clinical use depend on active bacterial growth to exert their effect. However, a means to measure the in situ bacterial growth rate during infection has been lacking. Due to faithful coordination between chromosome replication and cell growth and division in E. coli, chromosome replication provides a quantitative measure of the bacterial growth rate. In this study, we explored the potential for inferring in situ bacterial growth rate from a single urine sample in patients with E. coli bacteriuria by differential genome quantification (ori:ter) performed by quantitative PCR. We found active bacterial growth in almost all samples. However, this occurs with day-to-day and inter-patient variability. Our observations indicate that chromosome replication provides not only a robust measure of bacterial growth rate, but it can also be used as a means to evaluate antibiotic effect.

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.

Probiotics Slow the Growth of Pathogenic Bacteria

2019 ◽  
Vol 14 (1) ◽  
pp. 28-31 ◽  
Author(s):  
Rowles H. L.
Keyword(s):  
Growth Rate ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Diarrheal Disease ◽  
Growth Curves ◽  
Mortality Rates ◽  
Controlled Delivery ◽  
E Coli ◽  
Multiple Strains ◽  
Commercial Probiotics

Probiotics are live microorganisms, which when ingested in sufficient amounts, confer health benefits to the host by improving the gut microflora balance. The purpose of this research was to determine whether commercial probiotic products containing multitude of commensal bacteria would reduce the growth rate of pathogenic bacteria, specifically Escherichia coli and Salmonella typhimurium. Growth curves were established, and the growth rates were compared for samples of E. coli, S. typhimurium, Nature’s Bounty Controlled Delivery probiotic, Sundown Naturals Probiotic Balance probiotic, and cocultures of the pathogenic bacteria mixed with the probiotics. The findings of this research were that the commercial probiotics significantly reduced the growth rate of E. coli and S. typhimurium when combined in cocultures. Probiotics containing multiple strains may be taken prophylactically to reduce the risk of bacterial infections caused by E. coli and S. typhimurium. Probiotics could be used to reduce the high global morbidity and mortality rates of diarrheal disease.

scholarly journals Simplified Approach to Predict Food Safety through the Maximum Specific Bacterial Growth Rate as Function of Extrinsic and Intrinsic Parameters

2021 ◽  
Vol 5 (2) ◽  
pp. 22
Author(s):  
Pedro D. Gaspar ◽  
Joel Alves ◽  
Pedro Pinto
Keyword(s):  
Growth Rate ◽  
Food Safety ◽  
Information And Communication Technologies ◽  
Bacterial Growth ◽  
Low Cost ◽  
Extrinsic Factors ◽  
Bacterial Growth Rate ◽  
Modeling Tools ◽  
Simplified Approach ◽  
Food Safety And Quality

Currently, we assist the emergence of sensors and low-cost information and communication technologies applied to food products, in order to improve food safety and quality along the food chain. Thus, it is relevant to implement predictive mathematical modeling tools in order to predict changes in the food quality and allow decision-making for expiration dates. To perform that, the Baranyi and Roberts model and the online tool Combined Database for Predictive Microbiology (Combase) were used to determine the factors that define the growth of different bacteria. These factors applied to the equation that determines the maximum specific growth rate establish a relation between the bacterial growth and the intrinsic and extrinsic factors that define the bacteria environment. These models may be programmed in low-cost wireless biochemical sensor devices applied to packaging and food supply chains to promote food safety and quality through real time traceability.

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.

scholarly journals CONSERVATION OF NUCLEIC ACIDS DURING BACTERIAL GROWTH

1954 ◽  
Vol 38 (2) ◽  
pp. 145-148 ◽  
Author(s):  
A. D. Hershey
Keyword(s):  
Characteristic Feature ◽  
Nucleic Acids ◽  
Bacterial Growth ◽  
Cellular Growth ◽  
E Coli

In experiments of 6 hours duration, no replacement of phosphorus or purine and pyrimidine carbon in DNA, nor flow of these atoms from RNA to DNA, could be detected in rapidly growing cultures of E. coli. The slow replacement that has been demonstrated for many substances in non-proliferating tissues of other organisms, though it may occur also in bacteria, is not greatly accelerated under conditions of rapid cellular growth, and therefore cannot be a characteristic feature of synthetic processes.

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