E. coli growth curve assay in BG-11 + sucrose v1

2021 ◽  
Author(s):  
sanjana not provided
Keyword(s):  
Proper Time ◽  
Growth Curves ◽  
Growth Conditions ◽  
Butanol Production ◽  
Time Intervals ◽  
Sucrose Consumption ◽  
E Coli ◽  
Slow Growing ◽  
Over Time ◽  
Coli Growth

To obtain growth curves of KJK01 and pCSCX-KJK01 in BG-11 + sucrose and to characterize their growth. This also serves to estimate sucrose consumption and butanol production over time. This can be adapted for any other bacteria as well by giveing proper growth conditions, and using appropriate wavelength to measure the OD and giving proper time intervals based on whether the bacteria is slow growing or fast growing.

scholarly journals Analysis of Escherichia coli Flagellin Gene Expression in Simulated Spaceflight Growth Conditions

2018 ◽  
Vol 7 (1) ◽  
pp. 50-53
Author(s):  
Kyle M. Hetrick ◽  
Elizabeth A. Juergensmeyer ◽  
Jeffrey O. Henderson
Keyword(s):  
Escherichia Coli ◽  
Growth Curves ◽  
Growth Conditions ◽  
Major Protein ◽  
Rt Pcr ◽  
Flagellin Gene ◽  
Phase Duration ◽  
E Coli ◽  
Convective Mixing ◽  
Final Cell Concentration

Population growth curves of Escherichia coli (E. coli) cultures propagated in spaceflight environments demonstrate an extended log phase duration and an increased final cell concentration compared to E. coli cultures grown on Earth. We suggest that during spaceflight, a lack of convective mixing in the growth medium alters a cell’s microenvironment such that the cell at first devotes its resources primarily to motility and later shifts most of its resources to reproduction. As flagellin is the major protein component of flagella, the motility structure of E. coli, we propose that the expression of the flagellin gene (fliC) can be used as a diagnostic marker for determining if the bacterium is in fact altering its allocation of cellular resources to motility during specific growth phases. We have used semiquantitative RT-PCR to analyze the expression of fliC in cultures grown in laboratory apparatus that simulate various aspects of the spaceflight environment. The data from this pilot study indicate that fliC expression increases initially under stationary, slow clinorotation, and fast clinorotation growth conditions, peaking at mid-exponential phase and decreasing dramatically in stationary phase. These data support the hypothesis that metabolic resources are being directed towards forming the flagellum, the bacteria motile structure, before shifting resources to growth, reproduction, and maintenance.

scholarly journals Analysis of Escherichia coli Flagellin Gene Expression in Simulated Spaceflight Growth Conditions

2018 ◽  
Author(s):  
Kyle M. Hetrick ◽  
Elizabeth A. Juergensmeyer ◽  
Jeffrey O. Henderson
Keyword(s):  
Escherichia Coli ◽  
Growth Curves ◽  
Growth Conditions ◽  
Major Protein ◽  
Rt Pcr ◽  
Flagellin Gene ◽  
Phase Duration ◽  
E Coli ◽  
Convective Mixing ◽  
Final Cell Concentration

SummaryPopulation growth curves of Escherichia coli (E. coli) cultures propagated in spaceflight environments demonstrate an extended log phase duration and an increased final cell concentration compared to E. coli cultures grown on Earth. We suggest that during spaceflight, a lack of convective mixing in the growth medium alters a cell’s microenvironment such that the cell at first devotes its resources primarily to motility and later shifts most of its resources to reproduction. As flagellin is the major protein component of flagella, the motility structure of E. coli, we propose that the expression of the flagellin gene (fliC) can be used as a diagnostic marker for determining if the bacterium is in fact altering its allocation of cellular resources to motility during specific growth phases. We have used semiquantitative RT-PCR to analyze the expression of fliC in cultures grown in laboratory apparatus that simulate various aspects of the spaceflight environment. The data from this pilot study indicate that fliC expression increases initially under stationary, slow clinorotation, and fast clinorotation growth conditions, peaking at mid-exponential phase and decreasing dramatically in stationary phase. These data support the hypothesis that metabolic resources are being directed towards forming the flagellum, the bacteria motile structure, before shifting resources to growth, reproduction, and maintenance.

scholarly journals Disruption of cells in biosolids affects E. coli dynamics in storage

2019 ◽  
Vol 2 (1) ◽  
pp. 101-112
Author(s):  
S. Fane ◽  
D. Madureira ◽  
A. Nocker ◽  
P. Vale ◽  
M. Rivas Casado ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Membrane Filtration ◽  
Cell Damage ◽  
Growth Curves ◽  
Shear Forces ◽  
E Coli ◽  
Colony Forming Units ◽  
Significant Difference ◽  
Research Findings ◽  
Coli Growth

Abstract Achieving microbial compliance during biosolids storage can be complicated by the unpredictable increase of Escherichia coli. Thermal treatment during anaerobic digestion (AD) and the effects of dewatering may be a significant factor contributing to indicator survival. Shear forces present during dewatering may promote cell damage, releasing nutrient for E. coli growth. The effect of cell damage on E. coli survival was assessed in laboratory-scale thermal and physical disruption experiments. E. coli growth curves for disrupted treatments were compared with control conditions and quantified using flow cytometry and membrane filtration techniques. A significant difference (p < 0.05) in the level of damaged cells between control and disrupted conditions was observed. For thermal and physical disruption treatments, the peak of E. coli concentration increased significantly by 1.8 Log and 2.4 Log (CFU (colony forming units) g−1 DS), respectively, compared with control treatments. Research findings contribute to the understanding of bacterial growth and death dynamics in biosolids.

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 Two Auxinic Herbicides Affect Brassica napus Plant Hormone Levels and Induce Molecular Changes in Transcription

Biomolecules ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1153
Author(s):  
Jutta Ludwig-Müller ◽  
Roman Rattunde ◽  
Sabine Rößler ◽  
Katja Liedel ◽  
Freia Benade ◽  
...  
Keyword(s):  
Brassica Napus ◽  
Expression Patterns ◽  
Growth Conditions ◽  
Growth Stages ◽  
Auxin Response ◽  
Time Points ◽  
Genes Encoding ◽  
Different Temperatures ◽  
Indigenous Plant ◽  
Over Time

With the introduction of the new auxinic herbicide halauxifen-methyl into the oilseed rape (Brassica napus) market, there is a need to understand how this new molecule interacts with indigenous plant hormones (e.g., IAA) in terms of crop response. The aim of this study was to investigate the molecular background by using different growth conditions under which three different auxinic herbicides were administered. These were halauxifen-methyl (Hal), alone and together with aminopyralid (AP) as well as picloram (Pic). Three different hormone classes were determined, free and conjugated indole-3-acetic acid (IAA), aminocyclopropane carboxylic acid (ACC) as a precursor for ethylene, and abscisic acid (ABA) at two different temperatures and growth stages as well as over time (2–168 h after treatment). At 15 °C growth temperature, the effect was more pronounced than at 9 °C, and generally, the younger leaves independent of the developmental stage showed a larger effect on the alterations of hormones. IAA and ACC showed reproducible alterations after auxinic herbicide treatments over time, while ABA did not. Finally, a transcriptome analysis after treatment with two auxinic herbicides, Hal and Pic, showed different expression patterns. Hal treatment leads to the upregulation of auxin and hormone responses at 48 h and 96 h. Pic treatment induced the hormone/auxin response already after 2 h, and this continued for the other time points. The more detailed analysis of the auxin response in the datasets indicate a role for GH3 genes and genes encoding auxin efflux proteins. The upregulation of the GH3 genes correlates with the increase in conjugated IAA at the same time points and treatments. Also, genes for were found that confirm the upregulation of the ethylene pathway.

Microbial Growth Response to Hydrogel Encapsulated Quantum Dot Nanospheres

2007 ◽  
Vol 1064 ◽  
Author(s):  
Somesree GhoshMitra ◽  
Tong Cai ◽  
Santaneel Ghosh ◽  
Arup Neogi ◽  
Zhibing Hu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Growth Response ◽  
Microbial Growth ◽  
Biological Effects ◽  
Growth Curves ◽  
Swelling Properties ◽  
Growth Environment ◽  
E Coli ◽  
Cdte Qds ◽  
Biological Compatibility

ABSTRACTQuantum dots (QDs) are now used extensively for labeling in biomedical research due to their unique photoluminescence behavior, involving size-tunable emission color, a narrow and symmetric emission profile and a broad excitation range [1]. Uncoated QDs made of CdTe core are toxic to cells because of release of Cd2+ ions into the cellular environment. This problem can be partially solved by encapsulating QDs with polymers, like poly(N-isopropylacrylamide) (PNIPAM) or poly(ethylene glycol) (PEG). Based on biological compatibility, fast response as well as pH, temperature and magnetic field dependent swelling properties, hydrogel nanospheres has become carriers of drugs, fluorescence labels, magnetic particles for hyperthermia applications and particles that have strong optical absorption profiles for optical excitation. The toxicity of uncoated QDs are known; however, there have been a very limited number of studies specially designed to assess thoroughly the toxicity of nanosphere encapsulated QDs against QD density and dosing level.In this work, we present preliminary studies of biological effects of a novel QD based nanomaterial system on Escherichia coli (E. coli) bacteria. Cadmium chalcogenide QDs provide the most attractive fluorescence labels in comparison with routine dyes or metal complexes. Nanospheres on the other hand are the most commonly used carriers of fluorescence labels for fluorescence detection. The integration of fluorescent QDs in nanospheres therefore provides a new generation of fluorescence markers for biological assays. Hydrogels based on PNIPAM is a well known thermoresponsive polymer that undergoes a volume phase transition across the low critical solution (LCST) [2]. Therefore, the inherent temperature-sensitive swelling properties of PNIPAM offer the potentiality to control QD density within the nanospheres. In the present work, E. coli growth was monitored as E. coli served as a representation of how cells might respond in the presence of hydrogel encapsulated QDs in their growth environment. The present work describes the successful encapsulation of CdTe QDs in PNIPAM gel network. Microgel encapsulated QDs were synthesized by first preparing PNIPAM microspheres with cystaminebisacrylamide as a crosslinker and CdTe QDs capped with a stabilizer. The CdTe QDs were bonded into PNIPAM microgels through the replacement of CdTe's stabilizer inside PNIPAM microspheres. Growth curves were generated for E. coli growing in 20 mL of LB media containing hydrogel encapsulated QD nanospheres (400 nm diameter) at relatively higher (0.5mg/mL) and lower (0.01mg/mL) concentration of solution. From the growth curves, there was no evidence at lower concentration (0.01mg/mL) that the hydrogel encapsulated QDs prevent the microbial cells from growing but at higher concentration (0.5mg/mL), microbial growth was inhibited. Transmission Electron Microscopy (TEM) was used to characterize QD size and density inside the hydrogel nanospheres. Scanning Electron Microscopy (SEM) was used to observe size and morphology of the hydrogel particles. Further investigation is going on cell growth response at different QD density and to evaluate the limiting hydrogel concentration for different QD densities.

scholarly journals A Rhodobacter sphaeroides Protein Mechanistically Similar to Escherichia coli DksA Regulates Photosynthetic Growth

mBio ◽  
2014 ◽  
Vol 5 (3) ◽  
Author(s):  
Christopher W. Lennon ◽  
Kimberly C. Lemmer ◽  
Jessica L. Irons ◽  
Max I. Sellman ◽  
Timothy J. Donohue ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Structure Function ◽  
Rhodobacter Sphaeroides ◽  
Fatty Acid Content ◽  
Regulatory Protein ◽  
Growth Conditions ◽  
Globular Domain ◽  
Content Type ◽  
E Coli

ABSTRACTDksA is a global regulatory protein that, together with the alarmone ppGpp, is required for the “stringent response” to nutrient starvation in the gammaproteobacteriumEscherichia coliand for more moderate shifts between growth conditions. DksA modulates the expression of hundreds of genes, directly or indirectly. Mutants lacking a DksA homolog exhibit pleiotropic phenotypes in other gammaproteobacteria as well. Here we analyzed the DksA homolog RSP2654 in the more distantly relatedRhodobacter sphaeroides, an alphaproteobacterium. RSP2654 is 42% identical and similar in length toE. coliDksA but lacks the Zn finger motif of theE. coliDksA globular domain. Deletion of the RSP2654 gene results in defects in photosynthetic growth, impaired utilization of amino acids, and an increase in fatty acid content. RSP2654 complements the growth and regulatory defects of anE. colistrain lacking thedksAgene and modulates transcriptionin vitrowithE. coliRNA polymerase (RNAP) similarly toE. coliDksA. RSP2654 reduces RNAP-promoter complex stabilityin vitrowith RNAPs fromE. coliorR. sphaeroides, alone and synergistically with ppGpp, suggesting that even though it has limited sequence identity toE. coliDksA (DksAEc), it functions in a mechanistically similar manner. We therefore designate the RSP2654 protein DksARsp. Our work suggests that DksARsphas distinct and important physiological roles in alphaproteobacteria and will be useful for understanding structure-function relationships in DksA and the mechanism of synergy between DksA and ppGpp.IMPORTANCEThe role of DksA has been analyzed primarily in the gammaproteobacteria, in which it is best understood for its role in control of the synthesis of the translation apparatus and amino acid biosynthesis. Our work suggests that DksA plays distinct and important physiological roles in alphaproteobacteria, including the control of photosynthesis inRhodobacter sphaeroides. The study of DksARsp, should be useful for understanding structure-function relationships in the protein, including those that play a role in the little-understood synergy between DksA and ppGpp.

Identical twins and developmental stability

1962 ◽  
Vol 4 (1) ◽  
pp. 144-164 ◽  
Author(s):  
C. S. Taylor
Keyword(s):  
Growth Curves ◽  
Identical Twins ◽  
Body Measurements ◽  
Frequency Distributions ◽  
Stability Of Development ◽  
Mean Size ◽  
Degree Of Maturity ◽  
The Stability ◽  
Average Size ◽  
Slow Growing

1. The stability with which dairy cattle develop in body size up to 2 years of age was studied in 60 pairs of uniformly treated identical twins, i.e. an assessment was made of the influence of season, genotype, mean size of twin pair, age and degree of maturity on the level of within-pair variability.2. The frequency distributions of size differences shown by one-egg twins were in many cases decidedly leptokurtic.3. The similarity in size of the identical twins studied was only slightly, if at all, influenced by season. Within-pair variability under free outdoor grazing was certainly not any greater than under semi-controlled conditions indoors.4. The stability with which cattle grew appeared to depend on their genotype. Identical twins of the Shorthorn breed were somewhat more alike in size than were the twins of other breed-types; crossbreds were, on average, 50 % less stable than purebreds in average size () ; although crossbreds grew with somewhat greater stability ().5. Whatever their mean size, all pairs of identical twins of the same breed appeared to grow postnatally with more or less equal stability (). Small, slow growing pairs showed a greater disparity in average size ().6. Stability of development continually changed with age but not violently. Each body measurement appeared to have its own characteristic age trend. It is false to believe that variation automatically increases with increasing age. As they grew older, identical twins tended to become less alike in their later maturing body measurements whereas their early maturing body measurements tended to decline in variability. There was an overall trend with degree of maturity; variability steadily increased to a maximum and subsequently declined.7. It is suggested that environmentally induced instability of development may remain at a minimum level so long as growth curves are not seriously distorted from their exponential path to maturity.

scholarly journals Erosion and Subsequent Transport State of Escherichia coli from Cowpats

2005 ◽  
Vol 71 (6) ◽  
pp. 2875-2879 ◽  
Author(s):  
Richard William Muirhead ◽  
Robert Peter Collins ◽  
Philip James Bremer
Keyword(s):  
Escherichia Coli ◽  
Surface Waters ◽  
Overland Flow ◽  
Single Cells ◽  
Rainfall Event ◽  
Buffer Strips ◽  
Simulated Rainfall ◽  
E Coli ◽  
Unattached Fraction ◽  
Over Time

ABSTRACT Processes by which fecal bacteria enter overland flow and their transportation state to surface waters are poorly understood, making the effectiveness of measures designed to intercept this pathway, such as vegetated buffer strips, difficult to predict. Freshly made and aged (up to 30 days) cowpats were exposed to simulated rainfall, and samples of the cowpat material and runoff were collected. Escherichia coli in the runoff samples were separated into attached (to particles) and unattached fractions, and the unattached fraction was analyzed to determine if the cells were clumped. Within cowpats, E. coli grew for 6 to 14 days, rather than following a typical logarithmic die-off curve. E. coli numbers in the runoff correlated with numbers inside the cowpat. Most of the E. coli organisms eroded from the cowpats were transported as single cells, and only a small percentage (about 8%) attached to particles. The erosion of E. coli from cowpats and the state in which the cells were transported did not vary with time within a single rainfall event or over time as the cowpats aged and dried out. These findings indicate that cowpats can remain a significant source of E. coli in overland flow for more than 30 days. As well, most of the E. coli organisms eroded from cowpats will occur as readily transportable single cells.

Growth and development of the barren-ground caribou. II. Postnatal growth rates

1968 ◽  
Vol 46 (5) ◽  
pp. 1023-1029 ◽  
Author(s):  
E. H. McEwan
Keyword(s):  
Growth And Development ◽  
Growth Characteristic ◽  
Growth Curves ◽  
Postnatal Growth ◽  
Maintenance Costs ◽  
Cyclical Pattern ◽  
Body Weights ◽  
In Captivity ◽  
Growth Constants ◽  
Slow Growing

The growth curves of minimum body weights of fast-growing caribou reared in captivity and slow-growing wild caribou are compared. Captive animals exhibit a cyclical pattern of growth characteristic of other cervid species. The differences in the declining growth constants of wild caribou compared to captive caribou are attributed to environmental factors and activity, resulting in higher maintenance costs.

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