Bacterial Culture Population Graph From 2012 Eog Review

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Hey not-user here, don't know how the hell to work this site. Make certain you read item number 3 in the Phases department. At that place's some very unacademic statements beingness tossed around ("it'southward better to forget this"), thought you might desire to fix that upwards. Love <three Edit;some other users: Omg exponential growth is really hard, all those doing biotech and bio stuff, dont requite upward........ love frank

          — Preceding unsigned comment added past 98.228.92.241 (talk) 04:08, xiii August 2012 (UTC)                      [reply]                            

The graph is certainly incorrect if "B" is supposed to look similar exponential growth. Michael Hardy 22:49, 22 May 2004 (UTC) [reply]

It says:

At exponential phase, bacteria are reproducing at their maximum rate; therefore, their number increases during this phase. It is a catamenia of exponential growth.

This is contradictory! It cannot exist growing at its maximum rate while it's growing exponentially. Run into exponential growth. While something is growing exponentially, its growth rate is e'er increasing; it's never at its maximum growth charge per unit. I can't help suspecting this of beingness a case of thinking that "exponential growth" merely means extremely or surprisingly rapid growth. Besides, the clarification makes it sound like the growth rate is jointly proportional to the present size and the amount by which the size falls brusk of the conveying capacity. That would make information technology approximately exponential in its early phases, but nowhere near exponential when the growth rate is maximum. Michael Hardy 20:36, 15 Jul 2004 (UTC)

If the number of bacteria is increasing exponentially, and each bacterium is reproducing at maximum rate, then the rate of increment tin can be increasing exponentially, no problems at all. RobertStar20 22:38, two November 2004 (UTC)

If what was meant was the each bacterium separately is reproducing at maximum charge per unit, and then the commodity is very unclear. Moreover, if each bacterium separately is reproducing faster at time t than at any other fourth dimension, so ane would look tiresome per capita growth a later times, and therefore the growth rate is non exponential. In exponential growth, the per capita growth charge per unit remains constant. If that varies, then growth is non exponential. Michael Hardy 22:44, 2 November 2004 (UTC)

If all the private bacterium are separately reproducing at maximum rate, so the whole colony is at its maximum rate at that point in time, i.eastward. it is incapable of reproducing any faster. However, I concord that the per capita growth rate at subsequently times volition be slower, then information technology is indeed non technically exponential. Looking at the exponential growth folio, possibly the logistic function is what it really is... only isn't this a flake too mathematical perchance? We demand a word which ways increasing at an increasing charge per unit, but non necessarily exponentially. Every bit for the graph existence incorrect, it's a log y-axis, so an exponential curve will become directly... if only it were really exponential :-). [Unrelated question: do your comments on this folio automatically appear on my talk page or what?] RobertStar20 23:19, ii Nov 2004 (UTC)

I'one thousand not entirely happy with the way this now reads; I'd similar to see something more explicit well-nigh the mathematical model before such a phrase as "exponential growth" is used in a way that makes it appear to exist meant literally. Simply maybe no one who knows this fabric has worked on this commodity. Michael Hardy 21:07, 8 Nov 2004 (UTC)

Bacteria definetly abound exponentially. The example of growing bacteria are used constantly to innovate, reinforce and evaluate understanding in high school math courses of exponential functions. Each bacteria has a period during which it will carve up. Obviously, atmospheric condition such as infinite, food supply, oestrus, light, etc... affect this rate, so we assume those factors are abiding. Suppose a given strain of bacteria, let's call it B1, divides every 4 hours. Assuming we start with say, 10 leaner, and the conditions don't modify, then you will have table as follows:

          Time (h)    Bacteria Count"
          0           ten
          four           20
          8           40
          12          80
          16          160
          20          320
          24          640
          .           .
          .           .
          .           .
        

          This growth is modelled by the equation B = 10 x (2 ^ h/four),   where B is the number of leaner   and h is the number of hours   (x ways multiply, ^ means exponent, / means divide)        

So, the discussion is hopefully resolved with the accepted mathematical notion: Bacteria divide at a constant charge per unit, hence their population grows exponentially.

How could that resolve the issue when the commodity says they do NOT grow exponentially? Michael Hardy 00:12, 12 December 2005 (UTC) [answer]

what yous added to the commodity was utter nonsense. The betoken at which growth is fastest, later on which information technology slows down, cannot be a time when it is growing exponentially. Michael Hardy 00:18, 12 December 2005 (UTC) [respond]

Sorry you experience that way. Perhaps i didn't explain it clearly? Or maybe I don't empathize the confusion. Maybe someone could help me format the table higher up...or could you at least explain what you mean by utter nonsense? Do you mean my assumption that bacteria sectionalization is constant?

I merely tried to reread your page, and information technology referenced the exponential growth page, which says, "Examples of exponential growth Biology. Microorganisms in a culture dish will abound exponentially, at beginning, subsequently the beginning microorganism appears (only and then logistically until the bachelor food is exhausted, when growth stops). "

If we assume the division of bacteria occurs at a constant rate (environment, other factors are constant) then the number of leaner in any population volition grow exponentially. It's the same for many types of populations, from rabbits to humans. If you lot assume that in that location is a abiding steady growth rate, then the number in a population grows exponentially over time.

Or put another style, without external stressors, a population size volition grow exponentially over time.

Have I missed something? This concept is equally old every bit Malthus at to the lowest degree, who, I believe, pointed out that a population grows exponentially but resource tend to grow linearly and hence each population volition tend to exhaust it's resource, inevitably.

I'd sure like to understand amend if there is something I'm missing, or something I'm non explaining well. I thought the confusion was whether or not bacteria divide exponentially. They don't, or at least, as far as i understand, the rate of division is constant for given environmental factors. Only because they carve up, they double there number every time, which gives rise to an exponential function (base two).

I appreciate you taking the time to respond to my comments. Please retrieve I am very new to Wikipedia, and if I break ediquette I don't mean to. Jess.

http://www.cellsalive.com/ecoli.htm "LOG Phase: Once the metabolic mechanism is running, they start multiplying exponentially, doubling in number every few minutes."

http://www.ugrad.math.ubc.ca/coursedoc/math100/notes/zoo/andromed.html

http://www.abc.cyberspace.au/science/experimentals/stories/s1168046.htm "Bacteria double in numbers about every 20 minutes - that'south exponential growth!"

Yeah, you have missed something. What you missed is what this present article says. Bacteria do grow exponentially nether some circumstances, but this article is entirely explicit that those are not the circumstances considered here. Michael Hardy 00:33, 6 January 2006 (UTC) [reply]

I can't believe you're beingness and so difficult. I just looked again: it says "exponential phase" is when they're growing fastest. Obviously a misnomer. They're growing approximately exponentially only when they're growing much more than slowly. Why don't yous read what this article actually says? Michael Hardy 00:35, 6 January 2006 (UTC) [reply]

4 years on and the graph is all the same misleading... Since this graph represents the behaviour of many millions of bacteria, all transitions should be continuous (i.e. smooth) so the lag to log should curve to a straight line, the log to lag should curve to an approximately horizontal line, earlier curving down to the decease stage line (i'thou non certain what maths governs this stage). I'1000 no biologist, so my expertise is express certainly, but Michael Hardy was correct to question the graph on the basis of its maths, atleast. Perhaps we could ask the user who created the graph epitome to edit it.Hai2410 (talk) 17:17, 20 February 2010 (UTC) [reply]

Determination of maximum growth rate(viagra) [edit]

First of all this is what I sympathise of information technology anyways. One time a bacterial population enter exponential phase as seen on the graph a theoretial maximum specific growth rate can exist derived from from the graph.

(The difference between the theoretical and actual growth charge per unit is determined by the concentration of limiting nutrient which is an essential growth factor necessary for bacterial growth that is consumed by bacteria earlier exhausting whatever other of the essential nutrients in the media.) The actual maximum specific growth rate or true maximum specific growth rate is determined in a chemostat. run across http://mic.sgmjournals.org/cgi/reprint/151/ten/3153 (for ref which states the reason they are growing approximately exponentially) They therefore could grow exponentially merely they don't for these reasons.

Determining maxium specific growth rate is a two footstep calculation.

Step 1: Determine the doubling time (generation time) the amount of fourth dimension taken for the amount of cells in a population to double. (Too chosen doubling time) for the population. The fourth dimension taken for the y value (bacterial cell number or turbidity of culture) to double. If the value doesn't increase extrapolate the line and read off your values.

Footstep ii:

Derive maximum specific growth charge per unit

maximum specific growth rate=Ln ii/doubling fourth dimension

For the sake of the adding, the fact that information technology is an approx value is close to the actual value is but going to make a small difference in the calculation of growth charge per unit. (follow this methodology and repeat it a number of times to reduce your error). Leaner have different maximum specific growth rates depending on the experimental conditions such as the media used if non stressed diverting the energy used for growth into non-growth processes into adaptation I think the merely variable is the concentration of limiting nutrient which changes depending on the media used.

If you would similar to determine the actual growth charge per unit you need to found a bacterial civilisation in a chemostat.

Alter the dilution rate of the chemostat such that the bacterial population (as measured by culture turbidity, or cell number cfu/ml) remains abiding over time.

Oh yeah dilution rate = menses charge per unit (the rate of addition of media to the chemostat) divided by the volume of the chemostat civilisation. likewise run into paper maths explained ameliorate http://mic.sgmjournals.org/cgi/reprint/151/10/3153

Compare to values obained for batch civilization and volia you accept calculated your actual maximum specific growth charge per unit and validated your result using two methods. The results concord (I've washed it myself)

So exponential phase or is where a close approximation of exponential growth is used to calculate a close approximation of doubling time which is in plow used to derive a close approximation of maximum specific growth charge per unit as obtained past a graph monitoring bacterial growth in batch culture is a method of determining growth.

A graph displaying exponential growth and does non look all that different from the ane displayed in the figure depicting a bacterial population experiencing log growth occuring during log phase associated with this article. However it is not quite exactly strictly speaking true every bit true log growth cannot be derived because of the dependency on concentration of limiting nutrient in the media Lilypink (talk) 18:03, 24 January 2008 (UTC) [reply]

Actually this is part of a much larger discussion almost what happens in nature and what happens in culture; the question might exist phrased: "What is acclimation and what is development?" Information technology is a problem inherent in typological thinking. As a signal of fact, bacteria are never (information technology seems) adjusted to an surroundings in which every nutrient is nowadays completely in backlog. Instead, they have all sorts of throttles on their growth, which can be removed by diverse means. The 'deeper' the throttle, the more difficult to remove and the more difficult to reestablish. So there are all sorts of little things that a bacteria can do to suit to slightly more rich environs for a short time, but over time information technology becomes further and further adapted to a regularly rich environment. Eventually it will showtime picking up mutations, some more routine and predictable than others (like cassette mechanisms), to more or less permanently change its maximum doubling rate. The shortest term up and downward regulation we probably never see in the lab, unless we produce microscale nutrient patches in a microfluidics device (come across the work of F. Azam, J. Seymour, or R. Stocker). The medium scale is probably what we depict as lag stage, where the growth rate is less than we will see later in the civilization. People who work on this know that max. growth rate is actually highly dependent non only on strain and media and temperature, but on inoculation size and observable population density. Anyway, you lot can create a system in which there is no limiting food - every nutrient is in excess - and try to measure the growth rate, simply this charge per unit keeps changing equally the organisms keep to adapt. Anyway, yous practice have periods of truthful log growth, with a fixed doubling fourth dimension, to be sure. You just have to discover at the appropriate temporal and spatial scales. Bckirkup (talk) 15:26, 25 January 2008 (UTC) [answer]

I call back "Bacterial Growth Curve" should redirect to this folio. It doesn't seem to exist equally a page on its ain, just it would make sense for it to signal here. No? —Preceding unsigned comment added by 24.47.186.143 (talk) 17:37, 2 April 2008 (UTC) [respond]

As I empathise it, exponential growth refers to the population, which doubles at a constant rate. An alternative term is "logarithmic growth" and this is defined in the Oxford Lexicon of Biochemistry and Molecular Biological science as "when the number of cells, or the cell mass, increases logarithmically (exponentially) with fourth dimension. The rate of increase at any time is proportional to the number of cells, or prison cell mass, present." The diagram with the growth phases colored in diverse shades of blue is a piddling inaccurate, as the menstruation between lag phase and the onset of exponential growth is marked as log phase, rather than lag stage. Log phase is merely the portion of the semi-log graph that is a straight line. Tim Vickers (talk) 17:07, 14 September 2009 (UTC) [reply]

I recollect that the term "logarithmic growth" should non be used in a full general encyclopedia like Wikipedia and I replaced it in some articles. No i but microbiologists volition understand it because the log is the Inverse role of the exponential, and many processes with a very irksome growth N(t)~log(t) are called logarithmic elsewhere (eastward.g. Binary search algorithm). No one would employ "quadratic growth" and "square-root growth" synonymously, either. --Tinz (talk) fifteen:22, xxx May 2010 (UTC) [reply]

As a mathematician, I agree that the term "log phase" is an atrocious misuse. "exponential phase" makes a lot more sense. But we are not in a position to modify the terms people apply.

Another point I would make is that Michael Hardy's complaint that the growth cannot exist maximal because it is increasing is merely a matter of choosing the right definition. The growth rate is best defined by something like the inverse of the time it takes the number of organisms to double. This growth rate remains constant in the ideal exponential growth.

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1. Re = constructive reproduction number, sometimes besides chosen Rt, is the number of people in a population who can be infected by an individual at any specific time. Information technology changes as the population becomes increasingly immunized, either by private immunity following infection or past vaccination, and too equally people die; and
2. R0 = the basic reproduction number is defined as the number of cases that are expected to occur on average in a homogeneous population equally a result of infection by a single private, when the population is susceptible at the get-go of an epidemic, earlier widespread immunity starts to develop and before any attempt has been made at immunization - then if one person develops the infection and passes it on to two others, the R0 is 2.

Can anybody assist how these Ro and Re fit in a bacterial growth formula? Thy SvenAERTS (talk) 09:05, 19 July 2020 (UTC) [reply]

swainfial1942.blogspot.com

Source: https://en.wikipedia.org/wiki/Talk%3ABacterial_growth

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