How can I know the stationary phase of growth of several bacteria?
We are aiming to collect exoproteome of several bacteria. We know that the ideal time to collect exoproteome is during the stationary phase of a particular bacteria. Perhaps we have many bacteria and there is very limited literature on few bacterial stationary phase. Further the information is not available for many bacteria. Could someone suggest us any manual or a paper which describes stationary phase of these bacteria.
There is a rather... crude and time-consuming way of determining stationary growth phase that I know of - through turbidity. If there is no previous information on the growth curve details of the bacteria/bacterial strains of interest, then one good way to start is to use plot the growth curve in your laboratory by simple spectrophotometric analysis. The catch here is that you may need to stay at least overnight in your lab depending on the growth features of the bacteria (since you will have to "trace" the growth curve through time).
I found this reference the describes well what I remember on this technique: https://info.gbiosciences.com/blog/bacterial-growth-curves-turbidimetric-determination. However, I won't be surprised if there are now less laborious state-of-the-art techniques around, so let's wait for further responses here. Good luck!
Stationary phase is actually not a single thing. After a culture goes through exponential growth it then slows down and eventually enters stationary phase. As the cells remain in stationary phase then there is continued development for the bacteria to become dormant. So a cell after 12 hours of growth might be in stationary phase but it will be somewhat physiologically different than at 24 hours and certainly different than at 4 days, yet all are stationary phase.
For what you are doing, you need to decide if all the cells need to be precisely the same point.
But for practical purposes, with normal growing bacteria (not anaerobes or very slow growers), you could probably just pick 24 hours or 36 hours and they are likely to be pretty similar physiologically.
Hi,
The easiest way to check growth phase of any bacterial spp is to incubate it & after 12 hours check optical density after every 2 hours till 24 or 26 hours incubation.
By that you will can plot a graph from which you can get an idea that after how my hours your bacteria will be in stationary phase.
Your graph will be something like that after 14 hour OD will start increasing at 16-18 will be at peak (log phase) after that it starts decreasing which indicates that bacteria went into stationary phase ..
If still you have any confusion let me know.
Thanks,
Mubasher
The best way to know the stationary phase of a bacterial culture is to study the growth curve. It's a very easy spectrophotometric method where optical density has to be checked at regular interval till the culture density reached the stationary phase.
We can know the growth rate " a stationary phase " in which the number of viable bacteria cells remains the same. During the stationary phase, the rate of bacterial cell growth is equal to the rate of bacterial cell death.
In stationary phase, checked the rate of bacterial cell growth is equal with the rate of bacterial cell death.
In stationary phase living cells number are equal to dead cells and there are many secondary products
By monitoring the growth and number of cells through turbidity methods from 12 hrs,24hrs and 48hrs since the onset of the stationary phase may be different depending on the species in question
In general, in the stationary phase, the cell growth curve corresponds to the scenario when the level of cell proliferation rate equal to the level of a cell death rate. The stationary phase can be extended if certain nutritional conditions are created and toxic metabolic products are eliminated.
Stationary phase is defined as the phase when no. of bacterial binary fission/ growth becomes equal to the number of bacterial cell death. One of the most efficient and simple technique to access the different phases of bacterial growth curve is to use the Turbidimetric method which utilizes the principle of optical density (OD Value) measurement in spectrophotometer. This is done by plotting time on X axis and OD value on Y axis. As the number of bacteria increases the OD value also increases respectively until during stationary phases (which arrives at different time interval in different bacteria) is reached when the OD value becomes relatively constant. Normally OD value is calculated at 660 nm for yellow to brown samples. Sample measurement may be take from 1 to 3 hours.
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