Tests for 'how well' a bacterial &/or fungal culture is growing in d - (Dec/02/2015 )

Hi all, I've recently been put in charge of making and running my own experiment for the first time(3rd year biotech undergrad), I've run into a bit of a block, but first I'll give you the low down:

• Making up a number of media types using molasses and some other supplementation
• Using Aspergillus, Saccharomyces, and Escherichia as test organisms

Now the question:

• I'm looking for some methods to test how well the organisms are growing~ So I can compare the different concentrations and make ups of media.

What I have so far is: 

• Measure absorbance of broth cultures at 24, 48, 72 hours~
• For E. coli, check the acid content of the culture
• For Saccaromyces~ distill the alcohol content of fermentation and use a hydrometer to measure it.

I have at my disposal:

• FT-IR spectrometer
• UV/VIS spectrometer
• Some columns for chromatography~ though I must find out which ones we have.

I thank all of you for reading this far and appreciate all input,

Jesse

Synectome on Wed Dec 2 22:56:01 2015 said:

Hi all, I've recently been put in charge of making and running my own experiment for the first time(3rd year biotech undergrad), I've run into a bit of a block, but first I'll give you the low down:

• Making up a number of media types using molasses and some other supplementation
• Using Aspergillus, Saccharomyces, and Escherichia as test organisms

Now the question:

• I'm looking for some methods to test how well the organisms are growing~ So I can compare the different concentrations and make ups of media.

What I have so far is: 

• Measure absorbance of broth cultures at 24, 48, 72 hours~
• For E. coli, check the acid content of the culture
• For Saccaromyces~ distill the alcohol content of fermentation and use a hydrometer to measure it.

I have at my disposal:

• FT-IR spectrometer
• UV/VIS spectrometer
• Some columns for chromatography~ though I must find out which ones we have.

I thank all of you for reading this far and appreciate all input,

Jesse

 

You can also do a simple colony count.

I am not so sure how you start your experiment.

You have those cultures, ready at hand? or ?

Hi, thanks for the reply.

We haven't started the experiment yet, but this is the idea:

1) The media is prepared, we have the the cultures ready for inoculation.

2) when we grow them on these different types of media ~ What kind of tests are available to determine the success of growth ~ other than absorbence of broth media, and plate counts?

We will be doing both of those, I was just wondering what other things can we look at to make a comparison between the growth on one media versus another. Population is the obvious answer, I agree, I was just searching for another way to make comparisons.

Cheers,

Jesse

Synectome on Sun Dec 6 16:40:33 2015 said:

Hi, thanks for the reply.

 

We haven't started the experiment yet, but this is the idea:

 

1) The media is prepared, we have the the cultures ready for inoculation.

2) when we grow them on these different types of media ~ What kind of tests are available to determine the success of growth ~ other than absorbence of broth media, and plate counts?

 

We will be doing both of those, I was just wondering what other things can we look at to make a comparison between the growth on one media versus another. Population is the obvious answer, I agree, I was just searching for another way to make comparisons.

 

Cheers,

Jesse

Those are pretty much the best tests out there.

Plate colony count is often done so is measuring the OD.

Thank you~ I'm happy to have found this website, so many resources.

Synectome on Mon Dec 7 12:49:20 2015 said:

Thank you~ I'm happy to have found this website, so many resources.

A few remarks:

==> Measure absorbance of broth cultures at 24, 48, 72 hours~ => you are most likely going to inoculate the samples with the tip of a pipette? Or how are you going to do this?

Something you could do is the following: grow a pre-culture of the organisms to a specific OD, use the exact same volume (with the same OD) for every test you do (for every organism) to check the growhspeed-curve, starting from the same OD. This way you start with +- similar initial cell.

==> For E. coli, check the acid content of the culture

Not sure what the idea behind this is? Not all strains have the same effect, but you can use it as a general test.

==> For Saccaromyces~ distill the alcohol content of fermentation and use a hydrometer to measure it.

Thats a cool test, but again, hard to link it with growth. Not all of them will ferment at the same speed, but you can test it.

What is the test actually? Just to see how well they grow?

You can try different media, different incubation times, different temperatures.. and so on...