synchronous growth of E. coli

[Chris=Michi...@agr.kuleuven.ac.be]

I read in a microbiology textbook that synchronous growth can be the result of
temperature changes, nutrient limitation and other manipulations.
Could someone tell me how synchronization is generally achieved for E. coli,
and how it can be easily monitored?
Is it possible that just diluting an overnight E. coli broth culture grown at 37°C
into fresh medium at 30°C is sufficient for a few synchronized divisions?

Thanks in advance.

Chris Michiels
Lab. Food Microbiology
KU Leuven
Belgium

[Feras Hantash]

In article <7893237...@134.58.40.4>, Chris=Michiels%LMM%A...@agr.kuleuven.ac.be says:
>
>I read in a microbiology textbook that synchronous growth can be the result of
>temperature changes, nutrient limitation and other manipulations.
>Could someone tell me how synchronization is generally achieved for E. coli,
>and how it can be easily monitored?
>Is it possible that just diluting an overnight E. coli broth culture grown at 37°C
>into fresh medium at 30°C is sufficient for a few synchronized divisions?

You can not synchronize E.coli by subculturing them.
One of the best ways is to set up a chemostat and adjust the doubling time
of the culture so that to adjust the growth rate. There are lots of
references out there about setting up chemostats.
Another way is to work with a temperature sensitive mutant (that is not
a lethal mutation). Raise the temprature to that point to stop growth
then shift the temperature down to normal (say 37). this would provise
synchrony for a while.

Good Luck

Feras

[John W. Patching]

>Resent-date: Sun, 08 Jan 1995 21:00:34 +0000 (UT)
>Date: Sun, 08 Jan 1995 20:26:58 +0000 (GMT)
>Resent-from: server...@dl.ac.uk
>From: han...@ccwf.cc.utexas.edu (Feras Hantash)
>Subject: Re: synchronous growth of E. coli
>Sender: "bionet.microbiology mail newsgroup" <server...@dl.ac.uk>
>To: "bionet.microbiology mail newsgroup" <bione...@dl.ac.uk>
>Reply-to: han...@ccwf.cc.utexas.edu (Feras Hantash)
>X-Mailer: MXT V 12.16.1 Precedence: list X-Article-Number: bionet.microbiol=
ogy
> Msg # 1099 X-Listpath: bionet-news
>Comments: List problems/queries to <bio...@dl.ac.uk>
>Comments: To mail both the group and netnews send to (micr...@dl.ac.uk)
>
>In article <7893237...@134.58.40.4>,
>Chris=3DMichiels%LMM%A...@agr.kuleuven.ac.be says:
>>
>>I read in a microbiology textbook that synchronous growth can be=

the result of
>>temperature changes, nutrient limitation and other manipulations.

>>Could someone tell me how synchronization is generally achieved=

for E. coli,
>>and how it can be easily monitored?

>>Is it possible that just diluting an overnight E. coli broth culture=
grown at
>>37=83C
>>into fresh medium at 30=83C is sufficient for a few synchronized=
divisions?
>
>You can not synchronize E.coli by subculturing them.=20
>One of the best ways is to set up a chemostat and adjust the doubling=
time
>of the culture so that to adjust the growth rate. There are lots=

of
>references out there about setting up chemostats.

>Another way is to work with a temperature sensitive mutant (that=

is not
>a lethal mutation). Raise the temprature to that point to stop growth
>then shift the temperature down to normal (say 37). this would provise
>synchrony for a while.
>
>Good Luck
>
>Feras
>
>

Whilst you can do many things with chemostat cultures, I am afraid=
that
they cannot be used to produce synchronous growth in the way that=
is
suggested here.

John W. Patching
The Martin Ryan Marine Science Institute
University College Galway, Ireland

Email: John.P...@UCG.IE
Phone: +353-91-24411 Ext 2398
=46ax: +353-91-750456

[Ives100]

Unfortunately, it is not possible to obtain synchronous growth just by
diluting an
overnight culture. The best discussion of bacterial synchronization
techniques, with critiques of each is "Bacterial Growth and Division" by
Stephen Cooper (Academic Press) 1991. See chapter three for a discussion
and critique of several methods. Measuring synchrony entails making plate
counts of viable bacteria at frequent (10 min or less) intervals. Optical
density measurements will not work, as this technique measures cell mass
and not cell number.
Tom
Dougherty

[Feras Hantash]

>>You can not synchronize E.coli by subculturing them.=20
>>One of the best ways is to set up a chemostat and adjust the doubling=
> time
>>of the culture so that to adjust the growth rate. There are lots=
> of
>>references out there about setting up chemostats.
>>Another way is to work with a temperature sensitive mutant (that=
> is not
>>a lethal mutation). Raise the temprature to that point to stop growth
>>then shift the temperature down to normal (say 37). this would provise
>>synchrony for a while.
>>
>>Good Luck
>>
>>Feras
>>
>>
>Whilst you can do many things with chemostat cultures, I am afraid=
> that
>they cannot be used to produce synchronous growth in the way that=
> is
>suggested here.
>

I agree that setting up a chemostat by it self will not synchronize

the culture. However, in theory, you can use the chemostat to in induce

synchrony for a couple of generations. This can be accomplished by taking

a steady state growing culture under the nutrient limitation of choice,

and shutting down the nutrient supply. This would bring all the cells

in the population to the same growth point, i.e. finshed replication.

Now by starting the limiting nutrient supply again, a synchronized

culture should start. This process resembles the methods utilized

using the conventional batch cultures with nutrient shift down. The

advantage of utilizing a chemostat is that you know where the culture

to be synchronized is starting from, i.e. growth rate, limiting nutrient, mass doubling time

..etc.

The problem with this is the laborious techniques involved in setting

up a chemostat.

Best Regards

Feras Hantash